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Dynamic Evolution from Negative to Positive Photocharging in Colloidal CdS Quantum Dotsстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 16 января 2019 г.
- Авторы: Feng Donghai, Yakovlev Dmitri R., Pavlov Victor V., Rodina Anna V., Shornikova Elena V., Mund Johannes, Bayer Manfred
- Журнал: Nano Letters
- Том: 17
- Номер: 5
- Год издания: 2017
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 2844
- Последняя страница: 2851
- DOI: 10.1021/acs.nanolett.6b05305
- Аннотация: The optical properties of colloidal semiconductor nanocrystals are largely influenced by the trapping of charge carriers on the nano crystal surface. Different concentrations of electron and hole traps and different rates of their capture to the traps provide dynamical charging of otherwise neutral nanocrystals. We study the photocharging formation and evolution dynamics in CdS colloidal quantum dots with native oleic acid surface ligands. A time-resolved technique with three laser pulses (pump, orientation, and probe) is developed to monitor the photocharging dynamics with picosecond resolution on wide time scales ranging from picoseconds to milliseconds. The detection is based on measuring the coherent spin dynamics of electrons, allowing us to distinguish the type of carrier in the QD core (electron or hole). We find that although initially negative photocharging happens because of fast hole trapping, it eventually evolves to positive photocharging due to electron trapping and hole detrapping. The positive photocharging lasts up to hundreds of microseconds, at room temperature. These findings give insight into the photocharging process and provide valuable information for understanding the mechanisms responsible for the emission blinking in colloidal nanostructures.
- Добавил в систему: Мерзликин Александр Михайлович