Open AccessTransient absorption spectral dynamics of hybrid associates of CdS quantum dots and methylene blue dye
Author(s) -
С. А. Тихомиров
Publication year - 2021
Publication title -
doklady nacionalʹnoj akademii nauk belarusi
Language(s) - English
Resource type - Journals
eISSN - 2524-2431
pISSN - 1561-8323
DOI - 10.29235/1561-8323-2021-65-3-281-289
Subject(s) - ultrafast laser spectroscopy , thioglycolic acid , quantum dot , photochemistry , methylene blue , absorption (acoustics) , absorption spectroscopy , chemistry , spectroscopy , materials science , relaxation (psychology) , femtosecond , optoelectronics , photocatalysis , organic chemistry , optics , physics , psychology , social psychology , quantum mechanics , composite material , catalysis , laser
The transient absorption spectra dynamics for hybrid associates of colloidal CdS quantum dots, passivated by thioglycolic acid (CdS/TGA QDs), and methylene blue cationic dye molecules (MB+) were studied by femtosecond spectroscopy. It was established that one of the main channels of relaxation of the CdS/TGA QDs excitation energy in hybrid associates based on CdS/TGA QDs and MB+ is a fast energy transfer to the reduced forms of MB+ (MBOH•, MB•) that are formed still at the synthesis stage of samples. This channel strongly competes with the resonant energy transfer from the centers of radiative recombination in quantum dots to MB+. Therefore, for hybrid associates based on QDs/TGA and methylene blue, there is no any noticeable signal of the transient absorption corresponding to the triplet state of MB+ dye, which is then known to be actively involved in charge transfer.