Calculation of relative fluorescence quantum yield and Urbach energy of colloidal CdS QDs in various easily accessible solvents

Abstract

Atomically colloidal quantum dots are attractive for applications in far-reaching optoelectronic devices, due to engrossing optical properties. However, the relative low photoluminescence quantum yield (PLQY) of colloidal quantum dots was the main restriction, due to abundant defects. For the first time, we are here suggesting a possible source of deviation from the reported work is solvent dependence PLQY of CdS QDs. As most visible light-emitting QDs, colloid CdS QDs prepared in four common easily accessible solvents including water capped with thioglycolic acid (TGA) are taken into consideration here. Relative fluorescence quantum yield CdS QDs in DMSO are found to be highest i.e. 93 % among the solvents used. In addition to this Urbach energy was also calculated to have an idea about the density of states in CdS QDs.