Optical Properties of Single CdS Nanosheets

Abstract

We study the optical properties of single CdS nanosheets using micro-photoluminescence and time-resolved photoluminescence (PL) techniques. At low temperature, we observe high quantum efficiency and strongly polarized PL emission, indicating high-quality single-crystal nanosheet growth. Photoluminescence from A and B exciton states is observed with different spatial distributions, suggesting the existence of a variation in strain in the nanosheets. Time-resolved photoluminescence measurements show the exciton lifetime to be similar to 230 ps, longer than that of the near-band-edge emission, but shorter than the lifetime of defect-related emission in single CdS nanowires.