Photostimulated Luminescence of CuCl Quantum Dots in NaCl Crystals

Abstract

Photostimulated luminescence (PSL) was observed in CuCl quantum dots embedded in NaCl crystals at low temperatures of up to 120 K. This observation demonstrates that the quantum dot system is a new class of PSL materials. The thermal quenching, spontaneous decay and excitation-fluence dependence of the PSL are almost the same as those of persistent spectral hole burning (PSHB), indicating that the photoionization of quantum dots and the subsequent carrier capture at the traps near the quantum dots bring forth both PSL and PSHB. The traps form a Gaussian band and are considered to arise from Cu+ in NaCl. The requirement for the new class of PSL materials is the presence of quantum dots and nearby carrier traps in the host materials.