Photoluminescence of Ⅰ-Ⅶ Semiconductor Compounds. Sensitized Luminescence from 'Deep States' Recombination in CuBr/AgBr Nanocrystals

摘要

The photoluminescence (PL) properties of CuBr and CuBr/AgBr semiconductor nanocrystals (NCs) embedded in borosilicate glasses are measured under band-to-band excitation by a 355-nm Nd: YAG laser. We observed emission from CuBr (peaked at 520 nm) doped glass, which is associated with deep states in CuBr NCs. We also observed the sensitized blue to orange-red emission in CuBr/AgBr-glass systems (peaked at 520 and 570 nm), in which the luminescence intensity of CuBr decreases with increasing AgBr concentrations, while it is enhanced significantly around 570 nm. The results are discussed by the possible energy transfer between them, or by the multi-exitonic recombination process which ejects an excited carrier from CuBr to AgBr NCs.