One-pot synthesis of Ag–In–Ga–S nanocrystals embedded in a Ga2O3 matrix and enhancement of band-edge emission by Na+ doping

Abstract

I–III–VI-based semiconductor quantum dots (QDs) have been intensively explored because of their unique controllable optoelectronic properties. Here we report one-pot synthesis of Na-doped Ag–In–Ga–S (AIGS) QDs incorporated in a Ga₂O₃ matrix. The obtained QDs showed a sharp band-edge photoluminescence peak at 557 nm without a broad-defect site emission. The PL quantum yield (QY) of such QDs was 58%, being much higher than that of AIGS QDs without Na⁺ doping, 29%. The obtained Na-doped AIGS/Ga₂O₃ composite particles were used as an emitting layer of green QD light-emitted diodes. A sharp electroluminescence (EL) peak was observed at 563 nm, being similar to that in the PL spectrum of the QDs used. The external quantum efficiency of the device was 0.6%.