KCS

Quantum dots (QDs) prepared by colloidal synthesis usually show a monodisperse but wide size distribution that results in a rather broad emission spectrum. To reduce the emission band width and to tune the emission color, we carried out the photochemical etching of InP QDs. InP QDs were synthesized by a one-pot process and the photochemical etching of as-synthesized InP QDs was performed in chloroform by using a high power 532 nm laser. Photochemical etching processes were monitored by absorption and emission spectroscopy. After photoirradiation, the band-edge wavelength was shifted to blue, indicating the reduction in quantum size. The rate of etching varied with additives. After reducing the size by photochemical etching, resulting InP QDs were overcoated with a layer of ZnS shell, and their optical properties were characterized. The photochemical etching of compound semiconductor QDs is a useful tool to overcome the batch-to-batch variation in colloidal growth processes.