TY  - JOUR
AU  - Djurišić, Ivana
AU  - Dražić, Miloš
AU  - Tomović, Aleksandar
AU  - Spasenović, Marko
AU  - Sljivancanin, Zeljko
AU  - Jovanović, Vladimir P.
AU  - Žikić, Radomir
PY  - 2020
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1346
AB  - Fast, reliable, and inexpensive DNA sequencing is an important pursuit in healthcare, especially in personalized medicine with possible deep societal impacts. Despite significant progress in various nanopore-based sequencing configurations, challenges that remain in resolution and chromosome-size-long readout call for new approaches. Here we found strong rectification in the transversal current during single-stranded DNA translocation through a nanopore with side-embedded N-terminated carbon nanotube electrodes. Employing density functional theory and nonequilibrium Green's function formalisms, we show that the rectifying ratio (response to square pulses of alternating bias) bears high nucleobase specificity. Rectification arises because of bias-dependent resistance asymmetry on the deoxyribonucleotide-electrode interfaces. The asymmetry induces molecular charging and highest occupied molecular orbital pinning to the electrochemical potential of one of the electrodes, assisted by an in-gap electric-field effect caused by dipoles at the terminated electrode ends. We propose the rectifying ratio, due to its order-of-magnitude-difference nucleobase selectivity and robustness to electrode-molecule orientation, as a promising readout quantifier for single-base resolution and chromosome-size-long single-read DNA sequencing. The proposed configurations are within experimental reach from the viewpoint of both nanofabrication and small current measurement.
PB  - Amer Chemical Soc, Washington
T2  - Acs Applied Nano Materials
T1  - DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N-Terminated Carbon Nanotube Electrodes
EP  - 3043
IS  - 3
SP  - 3034
VL  - 3
DO  - 10.1021/acsanm.0c00385
ER  - 

@article{
author = "Djurišić, Ivana and Dražić, Miloš and Tomović, Aleksandar and Spasenović, Marko and Sljivancanin, Zeljko and Jovanović, Vladimir P. and Žikić, Radomir",
year = "2020",
abstract = "Fast, reliable, and inexpensive DNA sequencing is an important pursuit in healthcare, especially in personalized medicine with possible deep societal impacts. Despite significant progress in various nanopore-based sequencing configurations, challenges that remain in resolution and chromosome-size-long readout call for new approaches. Here we found strong rectification in the transversal current during single-stranded DNA translocation through a nanopore with side-embedded N-terminated carbon nanotube electrodes. Employing density functional theory and nonequilibrium Green's function formalisms, we show that the rectifying ratio (response to square pulses of alternating bias) bears high nucleobase specificity. Rectification arises because of bias-dependent resistance asymmetry on the deoxyribonucleotide-electrode interfaces. The asymmetry induces molecular charging and highest occupied molecular orbital pinning to the electrochemical potential of one of the electrodes, assisted by an in-gap electric-field effect caused by dipoles at the terminated electrode ends. We propose the rectifying ratio, due to its order-of-magnitude-difference nucleobase selectivity and robustness to electrode-molecule orientation, as a promising readout quantifier for single-base resolution and chromosome-size-long single-read DNA sequencing. The proposed configurations are within experimental reach from the viewpoint of both nanofabrication and small current measurement.",
publisher = "Amer Chemical Soc, Washington",
journal = "Acs Applied Nano Materials",
title = "DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N-Terminated Carbon Nanotube Electrodes",
pages = "3043-3034",
number = "3",
volume = "3",
doi = "10.1021/acsanm.0c00385"
}

Djurišić, I., Dražić, M., Tomović, A., Spasenović, M., Sljivancanin, Z., Jovanović, V. P.,& Žikić, R.. (2020). DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N-Terminated Carbon Nanotube Electrodes. in Acs Applied Nano Materials
Amer Chemical Soc, Washington., 3(3), 3034-3043.
https://doi.org/10.1021/acsanm.0c00385

Djurišić I, Dražić M, Tomović A, Spasenović M, Sljivancanin Z, Jovanović VP, Žikić R. DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N-Terminated Carbon Nanotube Electrodes. in Acs Applied Nano Materials. 2020;3(3):3034-3043.
doi:10.1021/acsanm.0c00385 .

Djurišić, Ivana, Dražić, Miloš, Tomović, Aleksandar, Spasenović, Marko, Sljivancanin, Zeljko, Jovanović, Vladimir P., Žikić, Radomir, "DNA Sequencing with Single-Stranded DNA Rectification in a Nanogap Gated by N-Terminated Carbon Nanotube Electrodes" in Acs Applied Nano Materials, 3, no. 3 (2020):3034-3043,
https://doi.org/10.1021/acsanm.0c00385 . .

TY  - JOUR
AU  - Matic, Zoran
AU  - Platisa, Mirjana M.
AU  - Kalauzi, Aleksandar
AU  - Bojic, Tijana
PY  - 2020
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1293
AB  - Objective: We explored the physiological background of the non-linear operating mode of cardiorespiratory oscillators as the fundamental question of cardiorespiratory homeodynamics and as a prerequisite for the understanding of neurocardiovascular diseases. We investigated 20 healthy human subjects for changes using electrocardiac RR interval (RRI) and respiratory signal (Resp) Detrended Fluctuation Analysis (DFA, alpha(1RRI), alpha(2RRI), alpha(1Resp), alpha(2Resp)), Multiple Scaling Entropy (MSERRI1-4, MSERRI5-10, MSEResp1-4, MSEResp5-10), spectral coherence (Coh(RRI-Resp)), cross DFA (rho(1) and rho(2)) and cross MSE (XMSE1-4 and XMSE5-10) indices in four physiological conditions: supine with spontaneous breathing, standing with spontaneous breathing, supine with 0.1 Hz breathing and standing with 0.1 Hz breathing. Main results: Standing is primarily characterized by the change of RRI parameters, insensitivity to change with respiratory parameters, decrease of Coh(RRI-Resp) and insensitivity to change of in rho(1), rho(2), XMSE1-4, and XMSE5-10. Slow breathing in supine position was characterized by the change of the linear and non-linear parameters of both signals, reflecting the dominant vagal RRI modulation and the impact of slow 0.1 Hz breathing on Resp parameters. Coh(RRI-Resp) did not change with respect to supine position, while rho(1) increased. Slow breathing in standing reflected the qualitatively specific state of autonomic regulation with striking impact on both cardiac and respiratory parameters, with specific patterns of cardiorespiratory coupling.
PB  - Frontiers Media Sa, Lausanne
T2  - Frontiers in Physiology
T1  - Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling
VL  - 11
DO  - 10.3389/fphys.2020.00024
ER  - 

@article{
author = "Matic, Zoran and Platisa, Mirjana M. and Kalauzi, Aleksandar and Bojic, Tijana",
year = "2020",
abstract = "Objective: We explored the physiological background of the non-linear operating mode of cardiorespiratory oscillators as the fundamental question of cardiorespiratory homeodynamics and as a prerequisite for the understanding of neurocardiovascular diseases. We investigated 20 healthy human subjects for changes using electrocardiac RR interval (RRI) and respiratory signal (Resp) Detrended Fluctuation Analysis (DFA, alpha(1RRI), alpha(2RRI), alpha(1Resp), alpha(2Resp)), Multiple Scaling Entropy (MSERRI1-4, MSERRI5-10, MSEResp1-4, MSEResp5-10), spectral coherence (Coh(RRI-Resp)), cross DFA (rho(1) and rho(2)) and cross MSE (XMSE1-4 and XMSE5-10) indices in four physiological conditions: supine with spontaneous breathing, standing with spontaneous breathing, supine with 0.1 Hz breathing and standing with 0.1 Hz breathing. Main results: Standing is primarily characterized by the change of RRI parameters, insensitivity to change with respiratory parameters, decrease of Coh(RRI-Resp) and insensitivity to change of in rho(1), rho(2), XMSE1-4, and XMSE5-10. Slow breathing in supine position was characterized by the change of the linear and non-linear parameters of both signals, reflecting the dominant vagal RRI modulation and the impact of slow 0.1 Hz breathing on Resp parameters. Coh(RRI-Resp) did not change with respect to supine position, while rho(1) increased. Slow breathing in standing reflected the qualitatively specific state of autonomic regulation with striking impact on both cardiac and respiratory parameters, with specific patterns of cardiorespiratory coupling.",
publisher = "Frontiers Media Sa, Lausanne",
journal = "Frontiers in Physiology",
title = "Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling",
volume = "11",
doi = "10.3389/fphys.2020.00024"
}

Matic, Z., Platisa, M. M., Kalauzi, A.,& Bojic, T.. (2020). Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling. in Frontiers in Physiology
Frontiers Media Sa, Lausanne., 11.
https://doi.org/10.3389/fphys.2020.00024

Matic Z, Platisa MM, Kalauzi A, Bojic T. Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling. in Frontiers in Physiology. 2020;11.
doi:10.3389/fphys.2020.00024 .

Matic, Zoran, Platisa, Mirjana M., Kalauzi, Aleksandar, Bojic, Tijana, "Slow 0.1 Hz Breathing and Body Posture Induced Perturbations of RRI and Respiratory Signal Complexity and Cardiorespiratory Coupling" in Frontiers in Physiology, 11 (2020),
https://doi.org/10.3389/fphys.2020.00024 . .

TY  - CHAP
AU  - Tomović, Aleksandar
AU  - Djurišić, Ivana
AU  - Žikić, Radomir
AU  - Pejić, Milan
AU  - Jovanović, Vladimir P.
PY  - 2017
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1898
AB  - There is an ongoing interest in organic materials due to their application in various organic electronic devices. However stability of organic materials limits their potential use. They are prone to degradation both during the working life and storage. One of the main causes is extrinsic degradation, under the influence of oxygen and moisture. This problem can be solved by encapsulation of devices. However no encapsulation is perfect. This paper presents a study of interaction of thin films of well-known organic blue emitters, namely N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) and 4,4′-bis(2,2-diphenylvinyl)-1,1′-biphenyl (DPVBi), with UV light in air. Films of both materials are stable in vacuum, but readily degrade in the presence of oxygen. Thus, the necessary condition for interaction (degradation) is the simultaneous presence of UV light and oxygen. Chemical analysis of irradiated films by mass and infrared spectroscopy revealed presence of oxidized species (impurities). These impurities are responsible for increased morphological stability of irradiated films and quenching of photoluminescence (PL). Only small amount of impurities, 0.4 % (0.2 %) for TPD (DPVBi), causes 50 % decrease of PL. This implies a non-trivial mechanism of quenching. For both molecules it was found that distance between impurities is smaller or equal to exciton diffusion length, which is the necessary condition for quenching. Following mechanism of quenching is proposed: exciton diffuses by hopping form one host molecule (DPVBi or TPD) to another through Förster resonant energy transfer in a random walk manner. If, during its lifetime, it comes to proximity of an impurity, a PL quenching process occurs. Findings of this study are important because they show that even a small amount of oxygen that penetrates a blue emitter layer would impair luminescence efficiency of a device. Moreover, the absorption of its own radiation would additionally contribute to the rate of degradation of a device. It is reasonable to expect that transport properties would also be affected when materials are used as a hole-transporting layer in OLEDs.
PB  - Atlantis Press, Paris
T2  - Proceedings of the IV Advanced Ceramics and Applications Conference
T1  - Interaction of UV Irradiation with Thin Films of Organic Molecules
EP  - 347
SP  - 317
DO  - 10.2991/978-94-6239-213-7_23
ER  - 

@inbook{
author = "Tomović, Aleksandar and Djurišić, Ivana and Žikić, Radomir and Pejić, Milan and Jovanović, Vladimir P.",
year = "2017",
abstract = "There is an ongoing interest in organic materials due to their application in various organic electronic devices. However stability of organic materials limits their potential use. They are prone to degradation both during the working life and storage. One of the main causes is extrinsic degradation, under the influence of oxygen and moisture. This problem can be solved by encapsulation of devices. However no encapsulation is perfect. This paper presents a study of interaction of thin films of well-known organic blue emitters, namely N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) and 4,4′-bis(2,2-diphenylvinyl)-1,1′-biphenyl (DPVBi), with UV light in air. Films of both materials are stable in vacuum, but readily degrade in the presence of oxygen. Thus, the necessary condition for interaction (degradation) is the simultaneous presence of UV light and oxygen. Chemical analysis of irradiated films by mass and infrared spectroscopy revealed presence of oxidized species (impurities). These impurities are responsible for increased morphological stability of irradiated films and quenching of photoluminescence (PL). Only small amount of impurities, 0.4 % (0.2 %) for TPD (DPVBi), causes 50 % decrease of PL. This implies a non-trivial mechanism of quenching. For both molecules it was found that distance between impurities is smaller or equal to exciton diffusion length, which is the necessary condition for quenching. Following mechanism of quenching is proposed: exciton diffuses by hopping form one host molecule (DPVBi or TPD) to another through Förster resonant energy transfer in a random walk manner. If, during its lifetime, it comes to proximity of an impurity, a PL quenching process occurs. Findings of this study are important because they show that even a small amount of oxygen that penetrates a blue emitter layer would impair luminescence efficiency of a device. Moreover, the absorption of its own radiation would additionally contribute to the rate of degradation of a device. It is reasonable to expect that transport properties would also be affected when materials are used as a hole-transporting layer in OLEDs.",
publisher = "Atlantis Press, Paris",
journal = "Proceedings of the IV Advanced Ceramics and Applications Conference",
booktitle = "Interaction of UV Irradiation with Thin Films of Organic Molecules",
pages = "347-317",
doi = "10.2991/978-94-6239-213-7_23"
}

Tomović, A., Djurišić, I., Žikić, R., Pejić, M.,& Jovanović, V. P.. (2017). Interaction of UV Irradiation with Thin Films of Organic Molecules. in Proceedings of the IV Advanced Ceramics and Applications Conference
Atlantis Press, Paris., 317-347.
https://doi.org/10.2991/978-94-6239-213-7_23

Tomović A, Djurišić I, Žikić R, Pejić M, Jovanović VP. Interaction of UV Irradiation with Thin Films of Organic Molecules. in Proceedings of the IV Advanced Ceramics and Applications Conference. 2017;:317-347.
doi:10.2991/978-94-6239-213-7_23 .

Tomović, Aleksandar, Djurišić, Ivana, Žikić, Radomir, Pejić, Milan, Jovanović, Vladimir P., "Interaction of UV Irradiation with Thin Films of Organic Molecules" in Proceedings of the IV Advanced Ceramics and Applications Conference (2017):317-347,
https://doi.org/10.2991/978-94-6239-213-7_23 . .

TY  - JOUR
AU  - Tomović, Aleksandar
AU  - Savić, J. J.
AU  - Bakic, N. Lj.
AU  - Bortel, G.
AU  - Faigel, G.
AU  - Žikić, Radomir
AU  - Jovanović, Vladimir P.
PY  - 2017
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1091
AB  - Prolonged annealing of pentacene thin films in air leads to the formation of nano- and micro-scale rod-shaped structures at temperatures equal to or higher than 130 degrees C. Scanning electron microscopy measurements indicated their crystalline structure, while UV-vis absorption spectra revealed presence of different species of oxidized pentacene, including 6,13-pentacenequinone. The mechanism of growth of microcrystals from oxidized pentacene molecules is discussed. Raman and UV-vis absorption spectra dependences on film thickness (in 30-300 nm range) and on thermal annealing conditions (in air and nitrogen at ambient pressure at 100 and 150 degrees C) were also studied. These spectra are not largely affected by annealing if it is performed in nitrogen at any of studied temperatures and annealing times (few hours to few days). However, if annealing is performed in air, at temperatures 130 degrees C and higher, changes in spectral features are significant due to film oxidation.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Vacuum
T1  - Oxidized pentacene micro-rods obtained by thermal annealing of pentacene thin films in air
EP  - 42
SP  - 36
VL  - 144
DO  - 10.1016/j.vacuum.2017.07.012
ER  - 

@article{
author = "Tomović, Aleksandar and Savić, J. J. and Bakic, N. Lj. and Bortel, G. and Faigel, G. and Žikić, Radomir and Jovanović, Vladimir P.",
year = "2017",
abstract = "Prolonged annealing of pentacene thin films in air leads to the formation of nano- and micro-scale rod-shaped structures at temperatures equal to or higher than 130 degrees C. Scanning electron microscopy measurements indicated their crystalline structure, while UV-vis absorption spectra revealed presence of different species of oxidized pentacene, including 6,13-pentacenequinone. The mechanism of growth of microcrystals from oxidized pentacene molecules is discussed. Raman and UV-vis absorption spectra dependences on film thickness (in 30-300 nm range) and on thermal annealing conditions (in air and nitrogen at ambient pressure at 100 and 150 degrees C) were also studied. These spectra are not largely affected by annealing if it is performed in nitrogen at any of studied temperatures and annealing times (few hours to few days). However, if annealing is performed in air, at temperatures 130 degrees C and higher, changes in spectral features are significant due to film oxidation.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Vacuum",
title = "Oxidized pentacene micro-rods obtained by thermal annealing of pentacene thin films in air",
pages = "42-36",
volume = "144",
doi = "10.1016/j.vacuum.2017.07.012"
}

Tomović, A., Savić, J. J., Bakic, N. Lj., Bortel, G., Faigel, G., Žikić, R.,& Jovanović, V. P.. (2017). Oxidized pentacene micro-rods obtained by thermal annealing of pentacene thin films in air. in Vacuum
Pergamon-Elsevier Science Ltd, Oxford., 144, 36-42.
https://doi.org/10.1016/j.vacuum.2017.07.012

Tomović A, Savić JJ, Bakic NL, Bortel G, Faigel G, Žikić R, Jovanović VP. Oxidized pentacene micro-rods obtained by thermal annealing of pentacene thin films in air. in Vacuum. 2017;144:36-42.
doi:10.1016/j.vacuum.2017.07.012 .

Tomović, Aleksandar, Savić, J. J., Bakic, N. Lj., Bortel, G., Faigel, G., Žikić, Radomir, Jovanović, Vladimir P., "Oxidized pentacene micro-rods obtained by thermal annealing of pentacene thin films in air" in Vacuum, 144 (2017):36-42,
https://doi.org/10.1016/j.vacuum.2017.07.012 . .

TY  - JOUR
AU  - Tomović, Aleksandar
AU  - Žikić, Radomir
AU  - Savić, Jelena J.
AU  - Bakić, Nataša Lj.
AU  - Jovanović, Vladimir P.
PY  - 2016
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1901
AB  - The influence of thermal annealing (in air and nitrogen at ambient pressure) on optical properties
of pentacene films, well-known material widely used in organic electronic devices, was studied. Pentacene films, whose thickness varies an order of magnitude (30 – 300 nm) depending on the position on the substrate, were polycrystalline at all thicknesses. Raman and UV-vis absorption spectra depend on the position on film implies changes of the film structure with the thickness. These spectra are not largely affected by annealing if it is not performed in air at temperatures higher than 100°C. Prolonged annealing in air, at temperatures higher than 100°C, leads to formation of nano- and micro-scale rod-shaped structures on film surface. Based on scanning electron microscopy measurements, it is supposed that these structures are crystalline. Their UV-vis absorbance indicates that they are composed of more than one species of oxidized pentacene molecules, including 6,13-pentacenequinone. Further study is necessary to precisely determine composition and structure of micro-rods, as well as the mechanism of their formation.
PB  - Serbian Ceramic Society
T2  - ADVANCED CERAMICS AND APPLICATION V - PROGRAM AND THE BOOK OF ABSTRACTS
T1  - Micro-rods of oxidized pentacene obtained by thermal annealing in air of pentacene thin films
SP  - 80
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_1901
ER  - 

@article{
author = "Tomović, Aleksandar and Žikić, Radomir and Savić, Jelena J. and Bakić, Nataša Lj. and Jovanović, Vladimir P.",
year = "2016",
abstract = "The influence of thermal annealing (in air and nitrogen at ambient pressure) on optical properties
of pentacene films, well-known material widely used in organic electronic devices, was studied. Pentacene films, whose thickness varies an order of magnitude (30 – 300 nm) depending on the position on the substrate, were polycrystalline at all thicknesses. Raman and UV-vis absorption spectra depend on the position on film implies changes of the film structure with the thickness. These spectra are not largely affected by annealing if it is not performed in air at temperatures higher than 100°C. Prolonged annealing in air, at temperatures higher than 100°C, leads to formation of nano- and micro-scale rod-shaped structures on film surface. Based on scanning electron microscopy measurements, it is supposed that these structures are crystalline. Their UV-vis absorbance indicates that they are composed of more than one species of oxidized pentacene molecules, including 6,13-pentacenequinone. Further study is necessary to precisely determine composition and structure of micro-rods, as well as the mechanism of their formation.",
publisher = "Serbian Ceramic Society",
journal = "ADVANCED CERAMICS AND APPLICATION V - PROGRAM AND THE BOOK OF ABSTRACTS",
title = "Micro-rods of oxidized pentacene obtained by thermal annealing in air of pentacene thin films",
pages = "80",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_1901"
}

Tomović, A., Žikić, R., Savić, J. J., Bakić, N. Lj.,& Jovanović, V. P.. (2016). Micro-rods of oxidized pentacene obtained by thermal annealing in air of pentacene thin films. in ADVANCED CERAMICS AND APPLICATION V - PROGRAM AND THE BOOK OF ABSTRACTS
Serbian Ceramic Society., 80.
https://hdl.handle.net/21.15107/rcub_rimsi_1901

Tomović A, Žikić R, Savić JJ, Bakić NL, Jovanović VP. Micro-rods of oxidized pentacene obtained by thermal annealing in air of pentacene thin films. in ADVANCED CERAMICS AND APPLICATION V - PROGRAM AND THE BOOK OF ABSTRACTS. 2016;:80.
https://hdl.handle.net/21.15107/rcub_rimsi_1901 .

Tomović, Aleksandar, Žikić, Radomir, Savić, Jelena J., Bakić, Nataša Lj., Jovanović, Vladimir P., "Micro-rods of oxidized pentacene obtained by thermal annealing in air of pentacene thin films" in ADVANCED CERAMICS AND APPLICATION V - PROGRAM AND THE BOOK OF ABSTRACTS (2016):80,
https://hdl.handle.net/21.15107/rcub_rimsi_1901 .

TY  - THES
AU  - Tomović, Aleksandar
PY  - 2015
UR  - https://nardus.mpn.gov.rs/handle/123456789/5766
UR  - http://eteze.bg.ac.rs/application/showtheses?thesesId=3070
UR  - https://fedorabg.bg.ac.rs/fedora/get/o:11332/bdef:Content/download
UR  - http://vbs.rs/scripts/cobiss?command=DISPLAY&base=70036&RID=47619599
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/6
AB  - Postoji veliki interes za organske materijale zbog njihove primene u različitim organskim elektronskim uređajima. Međutim stabilnost oragnskih materijala ograničava njihovu primenu. Oni su podložni degradaciji ne samo za vreme operacije uređaja već i za vreme skladištenja. Jedan od glavnih uzroka je degradacija usled spoljnih uticaja: svetlosti, vlage i kiseonika. Ovaj problem može da se prevaziđe putem enkapsulacije uređaja, ali nijedan vid enkapsulacije nije savršen. U prvom delu rada biće izložena studija degradacije tankih filmova N,N′- bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) i 4,4′-bis(2,2-diphenylvinyl)- 1,1′-biphenyl (DPVBi) pod uticajem UV zračenja u vazduhu. Filmovi oba materijala su stabilni u vakuumu, ali degradiraju u prisustvu kiseonika. Dakle, nepohodan uslov za degradaciju, potrebno je istovremeno prisustvo UV svetlosti i kiseonika. Hemijska analiza osvetljenih filmova izvršena uz pomoć NMR, masene i infracrvene spektroskopije pokazala je prisustvo oksidovanih vrsta (nečistoća). Nečistoće su odgovorne za povećanu morfološku stabilnost osvetljenih filmova i gašenje fotoluminescencije. Mala količina nečistoća, 0.4 % (0.2 %) u slučaju TPD (DPVBi), izaziva pad intenziteta fotoluminescencije od 50 %. Ovo implicira netrivijalni mehanizam gašenja fotoluminescencije. Za oba molekula je nađeno da je rastojanja između nečistoća manje ili približno jednako dužini difuzije ekscitona što je neophodan uslov za gašenje fotoluminescencije. Predložen je mehanizam gašenja: ekscitoni difunduju u skokovima od jednog do drugog molekula DPVBi (TPD) slučajnim hodom putem Forsterovog rezonatnog transfera energije. Ako u toku svog vremena života eksciton dođe u blizinu nečistoće dolazi do Deksterovog transfera energije i gašenja fotoluminescencije. Rezultati studije za DPVBi molekul su važni zato što pokazuju da i mala količina kiseonika u sloju DPVBi može ozbiljno da utiče na fotoluminescentnu efikasnost uređaja. Štaviše, apsorpcija sopstvenog zračenja (kod oba molekula, DPVBi i TPD) će dodatno da doprinese brzini degradacije uređaja. Razumno je pretpostaviti da će i transportne osobine biti narušene u slučaju kada se ovi materijali koriste kao sloj za transport šupljina u organskim svetlećim diodama.
AB  - There is an ongoing interest in organic materials due to their application in various organic electronic devices. However stability of organic materials limits their potential use. They are prone to degradation both during the working life and storage. One of the main causes is extrinsic degradation, under the influence of oxygen and moisture. This problem can be solved by encapsulation of devices. However no encapsulation is perfect. In the first part of this work a study of degradation of thin films of N,N′-bis(3- methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) and 4,4′-bis(2,2-diphenylvinyl)-1,1′-biphenyl (DPVBi) under UV irradiation in air is given. Films of both materials are stable in vacuum, but readily degrade in the presence of oxygen. Thus, the necessary condition for degradation is the simultaneous presence of UV light and oxygen. Chemical analysis of irradiated films by NMR, mass and infrared spectroscopy revealed presence of oxidized species (impurities). These impurities are responsible for increased morphological stability of irradiated films and quenching of photoluminescence. Only small amount of impurities, 0.4 % (0.2 %) for TPD (DPVBi), causes 50 % decrease of photoluminescence. This implies a non-trivial mechanism of quenching. For both molecules it was found that distance between impurities is smaller or equal to exciton diffusion length, which is the necessary condition for quenching. Following mechanism of quenching is proposed: exciton diffuses by hopping form one DPVBi (TPD) to another through FRET in a random walk manner. If, during its lifetime, it comes to proximity of an impurity, a Dexter-type energy transfer occurs and PL is quenched. Findings of DPVBi study are important because they show that even a small amount of oxygen that penetrates a DPVBi layer would impair luminescence efficiency of a device. Moreover, the absorption of own radiation (for DPVBi and TPD both) would additionally contribute to the rate of degradation of a device. It is reasonable to expect that transport properties would also be affected when materials are used as a holetransporting layer in OLEDs.
PB  - Univerzitet u Beogradu, Fizički fakultet
T1  - Elektronske osobine i morfologija tankih filmova organskih materijala dobijenih kombinatorijalnim naparavanjem iz gasne faze
T1  - Electronic properties and morphologies of thin films of organic molecules obtained by combinatorial deposition from gaseous phase
UR  - https://hdl.handle.net/21.15107/rcub_nardus_5766
ER  - 

@phdthesis{
author = "Tomović, Aleksandar",
year = "2015",
abstract = "Postoji veliki interes za organske materijale zbog njihove primene u različitim organskim elektronskim uređajima. Međutim stabilnost oragnskih materijala ograničava njihovu primenu. Oni su podložni degradaciji ne samo za vreme operacije uređaja već i za vreme skladištenja. Jedan od glavnih uzroka je degradacija usled spoljnih uticaja: svetlosti, vlage i kiseonika. Ovaj problem može da se prevaziđe putem enkapsulacije uređaja, ali nijedan vid enkapsulacije nije savršen. U prvom delu rada biće izložena studija degradacije tankih filmova N,N′- bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) i 4,4′-bis(2,2-diphenylvinyl)- 1,1′-biphenyl (DPVBi) pod uticajem UV zračenja u vazduhu. Filmovi oba materijala su stabilni u vakuumu, ali degradiraju u prisustvu kiseonika. Dakle, nepohodan uslov za degradaciju, potrebno je istovremeno prisustvo UV svetlosti i kiseonika. Hemijska analiza osvetljenih filmova izvršena uz pomoć NMR, masene i infracrvene spektroskopije pokazala je prisustvo oksidovanih vrsta (nečistoća). Nečistoće su odgovorne za povećanu morfološku stabilnost osvetljenih filmova i gašenje fotoluminescencije. Mala količina nečistoća, 0.4 % (0.2 %) u slučaju TPD (DPVBi), izaziva pad intenziteta fotoluminescencije od 50 %. Ovo implicira netrivijalni mehanizam gašenja fotoluminescencije. Za oba molekula je nađeno da je rastojanja između nečistoća manje ili približno jednako dužini difuzije ekscitona što je neophodan uslov za gašenje fotoluminescencije. Predložen je mehanizam gašenja: ekscitoni difunduju u skokovima od jednog do drugog molekula DPVBi (TPD) slučajnim hodom putem Forsterovog rezonatnog transfera energije. Ako u toku svog vremena života eksciton dođe u blizinu nečistoće dolazi do Deksterovog transfera energije i gašenja fotoluminescencije. Rezultati studije za DPVBi molekul su važni zato što pokazuju da i mala količina kiseonika u sloju DPVBi može ozbiljno da utiče na fotoluminescentnu efikasnost uređaja. Štaviše, apsorpcija sopstvenog zračenja (kod oba molekula, DPVBi i TPD) će dodatno da doprinese brzini degradacije uređaja. Razumno je pretpostaviti da će i transportne osobine biti narušene u slučaju kada se ovi materijali koriste kao sloj za transport šupljina u organskim svetlećim diodama., There is an ongoing interest in organic materials due to their application in various organic electronic devices. However stability of organic materials limits their potential use. They are prone to degradation both during the working life and storage. One of the main causes is extrinsic degradation, under the influence of oxygen and moisture. This problem can be solved by encapsulation of devices. However no encapsulation is perfect. In the first part of this work a study of degradation of thin films of N,N′-bis(3- methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) and 4,4′-bis(2,2-diphenylvinyl)-1,1′-biphenyl (DPVBi) under UV irradiation in air is given. Films of both materials are stable in vacuum, but readily degrade in the presence of oxygen. Thus, the necessary condition for degradation is the simultaneous presence of UV light and oxygen. Chemical analysis of irradiated films by NMR, mass and infrared spectroscopy revealed presence of oxidized species (impurities). These impurities are responsible for increased morphological stability of irradiated films and quenching of photoluminescence. Only small amount of impurities, 0.4 % (0.2 %) for TPD (DPVBi), causes 50 % decrease of photoluminescence. This implies a non-trivial mechanism of quenching. For both molecules it was found that distance between impurities is smaller or equal to exciton diffusion length, which is the necessary condition for quenching. Following mechanism of quenching is proposed: exciton diffuses by hopping form one DPVBi (TPD) to another through FRET in a random walk manner. If, during its lifetime, it comes to proximity of an impurity, a Dexter-type energy transfer occurs and PL is quenched. Findings of DPVBi study are important because they show that even a small amount of oxygen that penetrates a DPVBi layer would impair luminescence efficiency of a device. Moreover, the absorption of own radiation (for DPVBi and TPD both) would additionally contribute to the rate of degradation of a device. It is reasonable to expect that transport properties would also be affected when materials are used as a holetransporting layer in OLEDs.",
publisher = "Univerzitet u Beogradu, Fizički fakultet",
title = "Elektronske osobine i morfologija tankih filmova organskih materijala dobijenih kombinatorijalnim naparavanjem iz gasne faze, Electronic properties and morphologies of thin films of organic molecules obtained by combinatorial deposition from gaseous phase",
url = "https://hdl.handle.net/21.15107/rcub_nardus_5766"
}

Tomović, A.. (2015). Elektronske osobine i morfologija tankih filmova organskih materijala dobijenih kombinatorijalnim naparavanjem iz gasne faze. 
Univerzitet u Beogradu, Fizički fakultet..
https://hdl.handle.net/21.15107/rcub_nardus_5766

Tomović A. Elektronske osobine i morfologija tankih filmova organskih materijala dobijenih kombinatorijalnim naparavanjem iz gasne faze. 2015;.
https://hdl.handle.net/21.15107/rcub_nardus_5766 .

Tomović, Aleksandar, "Elektronske osobine i morfologija tankih filmova organskih materijala dobijenih kombinatorijalnim naparavanjem iz gasne faze" (2015),
https://hdl.handle.net/21.15107/rcub_nardus_5766 .

TY  - GEN
AU  - Tomović, Aleksandar
AU  - Jovanović, Vladimir P.
AU  - Žikić, Radomir
PY  - 2015
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1903
AB  - There is an ongoing interest in organic materials due to their application in various organic electronic devices. However stability of organic materials limits their potential use. They are prone to degradation both during the working life and storage. One of the main causes is extrinsic degradation, under the influence of oxygen and moisture. This problem can be solved by encapsulation of devices. However no encapsulation is perfect. In the first part of this work a study of degradation of thin films of N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) and 4,4′-bis(2,2-diphenylvinyl)-1,1′-biphenyl (DPVBi) under UV irradiation in air is given. Films of both materials are stable in vacuum, but readily degrade in the presence of oxygen. Thus, the necessary condition for degradation is the simultaneous presence of UV light and oxygen. Chemical analysis of irradiated films by NMR, mass and infrared spectroscopy revealed presence of oxidized species (impurities). These impurities are responsible for increased morphological stability of irradiated films and quenching of photoluminescence. Only small amount of impurities, 0.4 % (0.2 %) for TPD (DPVBi), causes 50 % decrease of photoluminescence. This implies a non-trivial mechanism of quenching. For both molecules it was found that distance between impurities is smaller or equal to exciton diffusion length, which is the necessary condition for quenching. Following mechanism of quenching is proposed: exciton diffuses by hopping form one DPVBi (TPD) to another through FRET in a random walk manner. If, during its lifetime, it comes to proximity of an impurity, a Dexter-type energy transfer occurs and PL is quenched. Findings of DPVBi study are important because they show that even a small amount of oxygen that penetrates a DPVBi layer would impair luminescence efficiency of a device. Moreover, the absorption of own radiation (for DPVBi and TPD both) would additionally contribute to the rate of degradation of a device. It is reasonable to expect that transport properties would also be affected when materials are used as a hole-transporting layer in OLEDs.
PB  - Serbian Ceramic Society
T2  - ADVANCED CERAMICS AND APPLICATION IV - PROGRAM AND THE BOOK OF ABSTRACTS
T1  - Interaction of UV irradiation with thin films of organic molecules
SP  - 43
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_1903
ER  - 

@misc{
author = "Tomović, Aleksandar and Jovanović, Vladimir P. and Žikić, Radomir",
year = "2015",
abstract = "There is an ongoing interest in organic materials due to their application in various organic electronic devices. However stability of organic materials limits their potential use. They are prone to degradation both during the working life and storage. One of the main causes is extrinsic degradation, under the influence of oxygen and moisture. This problem can be solved by encapsulation of devices. However no encapsulation is perfect. In the first part of this work a study of degradation of thin films of N,N′-bis(3-methylphenyl)-N,N′-bis(phenyl)benzidine (TPD) and 4,4′-bis(2,2-diphenylvinyl)-1,1′-biphenyl (DPVBi) under UV irradiation in air is given. Films of both materials are stable in vacuum, but readily degrade in the presence of oxygen. Thus, the necessary condition for degradation is the simultaneous presence of UV light and oxygen. Chemical analysis of irradiated films by NMR, mass and infrared spectroscopy revealed presence of oxidized species (impurities). These impurities are responsible for increased morphological stability of irradiated films and quenching of photoluminescence. Only small amount of impurities, 0.4 % (0.2 %) for TPD (DPVBi), causes 50 % decrease of photoluminescence. This implies a non-trivial mechanism of quenching. For both molecules it was found that distance between impurities is smaller or equal to exciton diffusion length, which is the necessary condition for quenching. Following mechanism of quenching is proposed: exciton diffuses by hopping form one DPVBi (TPD) to another through FRET in a random walk manner. If, during its lifetime, it comes to proximity of an impurity, a Dexter-type energy transfer occurs and PL is quenched. Findings of DPVBi study are important because they show that even a small amount of oxygen that penetrates a DPVBi layer would impair luminescence efficiency of a device. Moreover, the absorption of own radiation (for DPVBi and TPD both) would additionally contribute to the rate of degradation of a device. It is reasonable to expect that transport properties would also be affected when materials are used as a hole-transporting layer in OLEDs.",
publisher = "Serbian Ceramic Society",
journal = "ADVANCED CERAMICS AND APPLICATION IV - PROGRAM AND THE BOOK OF ABSTRACTS",
title = "Interaction of UV irradiation with thin films of organic molecules",
pages = "43",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_1903"
}

Tomović, A., Jovanović, V. P.,& Žikić, R.. (2015). Interaction of UV irradiation with thin films of organic molecules. in ADVANCED CERAMICS AND APPLICATION IV - PROGRAM AND THE BOOK OF ABSTRACTS
Serbian Ceramic Society., 43.
https://hdl.handle.net/21.15107/rcub_rimsi_1903

Tomović A, Jovanović VP, Žikić R. Interaction of UV irradiation with thin films of organic molecules. in ADVANCED CERAMICS AND APPLICATION IV - PROGRAM AND THE BOOK OF ABSTRACTS. 2015;:43.
https://hdl.handle.net/21.15107/rcub_rimsi_1903 .

Tomović, Aleksandar, Jovanović, Vladimir P., Žikić, Radomir, "Interaction of UV irradiation with thin films of organic molecules" in ADVANCED CERAMICS AND APPLICATION IV - PROGRAM AND THE BOOK OF ABSTRACTS (2015):43,
https://hdl.handle.net/21.15107/rcub_rimsi_1903 .

TY  - JOUR
AU  - Tomović, Aleksandar
AU  - Jovanović, Vladimir P.
AU  - Djurišić, Ivana
AU  - Cerovski, Viktor
AU  - Nastasijević, Branislav
AU  - Veielović, S. R.
AU  - Radulović, K.
AU  - Žikić, Radomir
PY  - 2015
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/876
AB  - The photoluminescence (PL) quenching mechanism of UV light and air-exposed amorphous thin films of 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi), a well-known hole-transport material used in organic light-emitting diodes, is studied. Thin films of DPVBi are stable when exposed to UV light in vacuum but tend to degrade if oxygen is present simultaneously. This is evident from the changes in UV-vis absorption spectra of the latter, showing that degradation rate of DPVBi films is linearly proportional to both oxygen concentration and UV light intensity. Mass spectrometry study of such films revealed a number of different oxygen-containing molecules and fragments of DPVBi thus confirming apparent photo-oxidation process. Also, DFT study of molecular DPVBi with and without oxygen was carried out, the IR spectra calculated for the lowest energy molecules found and the results are compared with the experiment. The most sensitive to photo-oxidation is DPVBi photoluminescence, which decays exponentially with respect to the concentration of photo-oxidized DPVBi molecules (impurities). The PL quantum yield of DPVBi thin film drops to a half of its original value for 0.2% of the impurities present, at which point an average distance between DPVBi molecules (the donors) and photo-oxidized DPVBi species (acceptors) is an order of magnitude larger than the separation between two adjacent molecules. This implies a need for a long-range Forster energy transfer, which we rule out based on the lack of a donor-acceptor spectral overlap. The apparent discrepancy can be removed by postulating exciton self-diffusion in DPVBi thin films, for which there is supporting evidence in existing literature.
PB  - Elsevier, Amsterdam
T2  - Journal of Luminescence
T1  - Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air
EP  - 210
SP  - 204
VL  - 167
DO  - 10.1016/j.jlumin.2015.06.036
ER  - 

@article{
author = "Tomović, Aleksandar and Jovanović, Vladimir P. and Djurišić, Ivana and Cerovski, Viktor and Nastasijević, Branislav and Veielović, S. R. and Radulović, K. and Žikić, Radomir",
year = "2015",
abstract = "The photoluminescence (PL) quenching mechanism of UV light and air-exposed amorphous thin films of 4,4'-bis(2,2-diphenylvinyl)-1,1'-biphenyl (DPVBi), a well-known hole-transport material used in organic light-emitting diodes, is studied. Thin films of DPVBi are stable when exposed to UV light in vacuum but tend to degrade if oxygen is present simultaneously. This is evident from the changes in UV-vis absorption spectra of the latter, showing that degradation rate of DPVBi films is linearly proportional to both oxygen concentration and UV light intensity. Mass spectrometry study of such films revealed a number of different oxygen-containing molecules and fragments of DPVBi thus confirming apparent photo-oxidation process. Also, DFT study of molecular DPVBi with and without oxygen was carried out, the IR spectra calculated for the lowest energy molecules found and the results are compared with the experiment. The most sensitive to photo-oxidation is DPVBi photoluminescence, which decays exponentially with respect to the concentration of photo-oxidized DPVBi molecules (impurities). The PL quantum yield of DPVBi thin film drops to a half of its original value for 0.2% of the impurities present, at which point an average distance between DPVBi molecules (the donors) and photo-oxidized DPVBi species (acceptors) is an order of magnitude larger than the separation between two adjacent molecules. This implies a need for a long-range Forster energy transfer, which we rule out based on the lack of a donor-acceptor spectral overlap. The apparent discrepancy can be removed by postulating exciton self-diffusion in DPVBi thin films, for which there is supporting evidence in existing literature.",
publisher = "Elsevier, Amsterdam",
journal = "Journal of Luminescence",
title = "Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air",
pages = "210-204",
volume = "167",
doi = "10.1016/j.jlumin.2015.06.036"
}

Tomović, A., Jovanović, V. P., Djurišić, I., Cerovski, V., Nastasijević, B., Veielović, S. R., Radulović, K.,& Žikić, R.. (2015). Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air. in Journal of Luminescence
Elsevier, Amsterdam., 167, 204-210.
https://doi.org/10.1016/j.jlumin.2015.06.036

Tomović A, Jovanović VP, Djurišić I, Cerovski V, Nastasijević B, Veielović SR, Radulović K, Žikić R. Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air. in Journal of Luminescence. 2015;167:204-210.
doi:10.1016/j.jlumin.2015.06.036 .

Tomović, Aleksandar, Jovanović, Vladimir P., Djurišić, Ivana, Cerovski, Viktor, Nastasijević, Branislav, Veielović, S. R., Radulović, K., Žikić, Radomir, "Fast photoluminescence quenching in thin films of 4,4 '-bis(2,2-diphenylvinyl)-1,1 '-biphenyl exposed to air" in Journal of Luminescence, 167 (2015):204-210,
https://doi.org/10.1016/j.jlumin.2015.06.036 . .

TY  - JOUR
AU  - Tomović, Aleksandar
AU  - Jovanović, Vladimir P.
AU  - Djurišić, Ivana
AU  - Cerovski, Viktor
AU  - Nastasijević, Branislav
AU  - Veličković, Suzana
AU  - Radulović, Katarina
AU  - Žikić, Radomir
AU  - Srdanov, Vojislav I.
PY  - 2014
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/1902
AB  - We studied degradation of 4,4′-bis(2,2′diphenyl vinyl)-1,1′-biphenyl (DPVBi), well know OLED material. Thermally evaporated thin films of DPVBi were irradiated with UV light in ambient, vacuum and under different oxygen pressures. The cause of degradation is reaction between UV excited DPVBi molecules and oxygen, via formation of singlet oxygen or electron transfer from excited DPVBi to molecular oxygen. Reaction rates depend on oxygen concentration and UV light intensity. These reactions lead to formation of oxidized species as evidenced by ASAP and MALDI-TOF mass spectroscopy. Photoluminescence quenching has two parts. One part is reversible and may imply formation of charge transfer complexes and the other is irreversible, caused by formation of oxidized species. IR and absorption spectra are studied by Density Functional Theory and results compared with the experiment.
PB  - Materials Research Society of Serbia
T2  - THE SIXTEENTH ANNUAL CONFERENCE YUCOMAT 2014 Programme and The Book of Abstracts
T1  - Degradation of thin 4,4′-bis(2,2′diphenyl vinyl)-1,1′-biphenyl films by UV light
SP  - 100
UR  - https://hdl.handle.net/21.15107/rcub_rimsi_1902
ER  - 

@article{
author = "Tomović, Aleksandar and Jovanović, Vladimir P. and Djurišić, Ivana and Cerovski, Viktor and Nastasijević, Branislav and Veličković, Suzana and Radulović, Katarina and Žikić, Radomir and Srdanov, Vojislav I.",
year = "2014",
abstract = "We studied degradation of 4,4′-bis(2,2′diphenyl vinyl)-1,1′-biphenyl (DPVBi), well know OLED material. Thermally evaporated thin films of DPVBi were irradiated with UV light in ambient, vacuum and under different oxygen pressures. The cause of degradation is reaction between UV excited DPVBi molecules and oxygen, via formation of singlet oxygen or electron transfer from excited DPVBi to molecular oxygen. Reaction rates depend on oxygen concentration and UV light intensity. These reactions lead to formation of oxidized species as evidenced by ASAP and MALDI-TOF mass spectroscopy. Photoluminescence quenching has two parts. One part is reversible and may imply formation of charge transfer complexes and the other is irreversible, caused by formation of oxidized species. IR and absorption spectra are studied by Density Functional Theory and results compared with the experiment.",
publisher = "Materials Research Society of Serbia",
journal = "THE SIXTEENTH ANNUAL CONFERENCE YUCOMAT 2014 Programme and The Book of Abstracts",
title = "Degradation of thin 4,4′-bis(2,2′diphenyl vinyl)-1,1′-biphenyl films by UV light",
pages = "100",
url = "https://hdl.handle.net/21.15107/rcub_rimsi_1902"
}

Tomović, A., Jovanović, V. P., Djurišić, I., Cerovski, V., Nastasijević, B., Veličković, S., Radulović, K., Žikić, R.,& Srdanov, V. I.. (2014). Degradation of thin 4,4′-bis(2,2′diphenyl vinyl)-1,1′-biphenyl films by UV light. in THE SIXTEENTH ANNUAL CONFERENCE YUCOMAT 2014 Programme and The Book of Abstracts
Materials Research Society of Serbia., 100.
https://hdl.handle.net/21.15107/rcub_rimsi_1902

Tomović A, Jovanović VP, Djurišić I, Cerovski V, Nastasijević B, Veličković S, Radulović K, Žikić R, Srdanov VI. Degradation of thin 4,4′-bis(2,2′diphenyl vinyl)-1,1′-biphenyl films by UV light. in THE SIXTEENTH ANNUAL CONFERENCE YUCOMAT 2014 Programme and The Book of Abstracts. 2014;:100.
https://hdl.handle.net/21.15107/rcub_rimsi_1902 .

Tomović, Aleksandar, Jovanović, Vladimir P., Djurišić, Ivana, Cerovski, Viktor, Nastasijević, Branislav, Veličković, Suzana, Radulović, Katarina, Žikić, Radomir, Srdanov, Vojislav I., "Degradation of thin 4,4′-bis(2,2′diphenyl vinyl)-1,1′-biphenyl films by UV light" in THE SIXTEENTH ANNUAL CONFERENCE YUCOMAT 2014 Programme and The Book of Abstracts (2014):100,
https://hdl.handle.net/21.15107/rcub_rimsi_1902 .

TY  - JOUR
AU  - Tomović, Aleksandar
AU  - Markesević, N.
AU  - Scarpellini, M.
AU  - Bovio, S.
AU  - Lucenti, E.
AU  - Milani, P.
AU  - Žikić, Radomir
AU  - Jovanović, Vladimir P.
AU  - Srdanov, V. I.
PY  - 2014
UR  - http://rimsi.imsi.bg.ac.rs/handle/123456789/812
AB  - Owing to their low glass transition temperature, T-g, amorphous thin films of N,N'-bis(3-methylphenyl)-N,N'bis(phenyl)benzidine (TPD) undergo morphological changes even at room temperature. It has been noticed previously that exposure to UV light can increase apparent T-g of TPD films and thus stabilize their morphology. However, the reason behind increase in structural stability was not examined at the time. Here we present evidence that TPD molecules undergo photo-oxidation in air when exposed to lambda approximate to 350 nm radiation and that less than 5% of the photo-oxidized species are needed to prevent dewetting of thin TPD films. We propose that photo-oxidized TPD species bind strongly to both ordinary TPD molecules and to terminal hydroxyl groups at the substrate surface, which decreases mobility of TPD molecules and makes thin TPD film less prone to morphology changes.
PB  - Elsevier Science Sa, Lausanne
T2  - Thin Solid Films
T1  - Stabilization of N,N '-bis(3-methylphenyl)-N,N '-bis(phenyl)benzidine thin film morphology with UV light
EP  - 103
SP  - 99
VL  - 562
DO  - 10.1016/j.tsf.2014.03.081
ER  - 

@article{
author = "Tomović, Aleksandar and Markesević, N. and Scarpellini, M. and Bovio, S. and Lucenti, E. and Milani, P. and Žikić, Radomir and Jovanović, Vladimir P. and Srdanov, V. I.",
year = "2014",
abstract = "Owing to their low glass transition temperature, T-g, amorphous thin films of N,N'-bis(3-methylphenyl)-N,N'bis(phenyl)benzidine (TPD) undergo morphological changes even at room temperature. It has been noticed previously that exposure to UV light can increase apparent T-g of TPD films and thus stabilize their morphology. However, the reason behind increase in structural stability was not examined at the time. Here we present evidence that TPD molecules undergo photo-oxidation in air when exposed to lambda approximate to 350 nm radiation and that less than 5% of the photo-oxidized species are needed to prevent dewetting of thin TPD films. We propose that photo-oxidized TPD species bind strongly to both ordinary TPD molecules and to terminal hydroxyl groups at the substrate surface, which decreases mobility of TPD molecules and makes thin TPD film less prone to morphology changes.",
publisher = "Elsevier Science Sa, Lausanne",
journal = "Thin Solid Films",
title = "Stabilization of N,N '-bis(3-methylphenyl)-N,N '-bis(phenyl)benzidine thin film morphology with UV light",
pages = "103-99",
volume = "562",
doi = "10.1016/j.tsf.2014.03.081"
}

Tomović, A., Markesević, N., Scarpellini, M., Bovio, S., Lucenti, E., Milani, P., Žikić, R., Jovanović, V. P.,& Srdanov, V. I.. (2014). Stabilization of N,N '-bis(3-methylphenyl)-N,N '-bis(phenyl)benzidine thin film morphology with UV light. in Thin Solid Films
Elsevier Science Sa, Lausanne., 562, 99-103.
https://doi.org/10.1016/j.tsf.2014.03.081

Tomović A, Markesević N, Scarpellini M, Bovio S, Lucenti E, Milani P, Žikić R, Jovanović VP, Srdanov VI. Stabilization of N,N '-bis(3-methylphenyl)-N,N '-bis(phenyl)benzidine thin film morphology with UV light. in Thin Solid Films. 2014;562:99-103.
doi:10.1016/j.tsf.2014.03.081 .

Tomović, Aleksandar, Markesević, N., Scarpellini, M., Bovio, S., Lucenti, E., Milani, P., Žikić, Radomir, Jovanović, Vladimir P., Srdanov, V. I., "Stabilization of N,N '-bis(3-methylphenyl)-N,N '-bis(phenyl)benzidine thin film morphology with UV light" in Thin Solid Films, 562 (2014):99-103,
https://doi.org/10.1016/j.tsf.2014.03.081 . .