Photoinduced Degradation of the Optical Properties of Colloidal Ag2S and CdS Quantum Dots Passivated by Thioglycolic Acid

Photostimulated control of luminescence quantum yield for colloidal Ag2S/2-MPA quantum dots

“…It is known that, under the inuence of laser radiation, the colloidal QDs degrade, and new channels of non-radiative recombination are formed. 10,11 To elucidate the factors responsible for the observed nonmonotonic dependence of the luminescence QY of Ag 2 S/2-MPA QDs on the exposure time, luminescence decays were analyzed for the investigated samples (Fig. 3).…”

“…In a number of studies, manifestations of photostimulated degradation of QD luminescence intensity were detected. [8][9][10][11][12][13] Random blinking of luminescence of single quantum dots was also demonstrated. [14][15][16] Such unwanted parasitic effects in the QD luminescence strongly limit the development of many advanced applications, including those associated with single-photon light sources for quantum informatics.…”

“…An appreciable photochemical activity of silver sulde affects the stability of the optical properties of colloidal Ag 2 S QDs due to structural changes under exposure to exciting radiation. 10,11 Photoprocesses arising in this case, pose the problem of obtaining Ag 2 S QDs with high stability of luminescence parameters, as well as searching for the ways of increasing the quantum yield of IR luminescence of the QDs.…”

“…10,11,23,26,31 In the case of using molecules of thioglycolic acid (TGA) as the passivating agent, a strong dependence of the QD optical properties on the sulfur concentration and the silver-sulfur ratio is observed. 10,11,[31][32][33] In the works, 10,11,31 it was assumed that the centers of radiative recombination of Ag 2 S QDs are of an interfacial nature. The low quantum yield of the QDs is explained, as a rule, by numerous surface defects formed during rapid intense release of sulfur atoms involved in the QD growth.…”

Room Temperature Silicon Detector for IR Range Coated with Ag2S Quantum Dots

“…The aqueous solutions of AgNO 3 and Na 2 S were used as the initial reagents. Aqueous synthesis of colloidal Ag 2 S QDs was carried out under conditions similar to those described in previous studies . To remove the reaction by‐products, acetone was used in aqueous colloidal Ag 2 S QDs solution, followed by centrifuging the solution.…”