Two-phase approach synthesis of high photoluminescence PbS quantum dots

Abstract Colloidal PbS quantum dots (QDs) with narrow size distribution were synthesized via a facile two-phase approach in this paper. By elaborate selection of solvent and protective agent, cubic PbS QDs with nearly spherical shape and average diameter of approximately 4.0 nm were synthesized. The as-prepared PbS QDs had a relatively narrow emission in the photoluminescence (PL) spectrum with an emission of maximum about 430 nm and full width at half maximum (FWHM) of about 80 nm. The PL peak red-shifted and the FWHM increased when reaction times were extended. However, improving synthesis temperatures, the PL peaks became more sharpening. Varying Pb/S molar ratios made no difference to PL peaks due to the protection of oleic acid.