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Фотоэлектрические свойства полиимидов на основе N,N’,N’’,N’’’ - замещенного парафенилендиамина и диангидридов ароматических тетракарбоновых кислот и их композитов с нанокристаллическим кремниемстатья
- Авторы: Румянцев Б.М., Der-Jang Liaw, Ying-Chi Huang, Берендяев В.И., Дорофеев С.Г., Кононов Н.Н., Зубов В.П., Ольхов А.А., Фетисов Г.В., Ищенко А.А.
- Журнал: Нанотехника
- Номер: 1
- Год издания: 2012
- Первая страница: 35
- Последняя страница: 41
- Аннотация: The photoelectric characteristics of the films of newly synthesized polyimides (PI) based on N, N ‘, N’’, N’’’-parafenilendiamin substituted dianhydrides and aromatic tetracarboxylic acids and their composites with nanocrystalline silicon (nc-Si) were investigated by Electrophotographic method. The photoelectric sensitivity (PES) of the films was observed in both visible and UV spectral regions. The analyses of experimental results demonstrate that the observed PES is due to the EDA charge-transfer interaction between donor and acceptor fragments of the PI chains, i. e. electronic D-A charge-transfer complexes (CTC). Main mechanism of photogeneration consists of a thermal field dissociation of the ion-radical pairs, kinetically coupled with the excited charge-transfer complexes. The second mechanism is photogeneration of long-lived photostimulated stabilized cation radicals of the donor fragments of the PI, which are holes (majority carriers) captured by deep centers (photostimulated currents). A sharp increase in the effective quantum yield of photogeneration at low field strengths (E < 10^5 V/cm) was observed for PI-containing nc-Si, which may explain the decrease in collection efficiency of charge carriers due to a decrease in the length of the migration of holes. Reducing the length of the migration of charge carriers by adding nc-Si indicates that the nanoparticles are scavengers of holes in the composite material. Nc-Si exhibit electron-donor properties and, as a more effective trapping centers of holes contribute to the stabilization and accumulation of radical cations.
- Добавил в систему: Фетисов Геннадий Владимирович