Fractals of graphene quantum dots in photoluminescence of shungite

Viewing shungite as loosely packed fractal nets of graphene-based (reduced graphene oxide, rGO) quantum dots (GQDs), we consider photoluminescence of the latter as a convincing proof of the structural concept as well as of the GQD attribution to individual rGO fragments. We study emission from shungite GQDs for colloidal dispersions in water, carbon tetrachloride, and toluene at both room and low temperatures. As expected, the photoluminescence of the GQD aqueous dispersions is quite similar to that of synthetic GQDs of the rGO origin. The morphological study of shungite dispersions shows a steady trend of GQDs to form fractals and to drastically change the colloid fractal structure caused by the solvent exchange. Spectral study reveals a dual character of the emitting centers: individual GQDs are responsible for the spectra position while the fractal structure of GQD colloids ensures high broadening of the spectra due to structural inhomogeneity, thus causing a peculiar dependence of the photoluminescence spectra on the excitation wavelength. For the first time, photoluminescence spectra of individual GQDs were observed in frozen toluene dispersions, which paves the way for a theoretical treatment of the GQD photonics. © 2014 Pleiades Publishing, Inc.

Авторы
Razbirin B.S.1 , Rozhkova N.N.2 , Sheka E.F. 3 , Nelson D.K.1 , Starukhin A.N.1
Редакторы
-
Издательство
-
Номер выпуска
5
Язык
Английский
Страницы
735-746
Статус
Опубликовано
Подразделение
-
Номер
-
Том
118
Год
2014
Организации
  • 1 Ioffe Physicotechnical Institute, Russian Academy of Sciences, St.-Petersburg 194021, Russian Federation
  • 2 Institute of Geology, Karelian Research Centre, Russian Academy of Sciences, Petrozavodsk 185910, Russian Federation
  • 3 Peoples' Friendship University of Russia, Moscow 117198, Russian Federation
Ключевые слова
Colloids; Fractals; Graphene; Semiconductor quantum dots; Spectroscopic analysis; Toluene; Aqueous dispersions; Colloidal dispersion; Excitation wavelength; Morphological study; Photoluminescence spectrum; Reduced graphene oxides; Structural inhomogeneities; Theoretical treatments; Photoluminescence
Дата создания
19.10.2018
Дата изменения
19.10.2018
Постоянная ссылка
https://repository.rudn.ru/ru/records/article/record/5009/