Spectroscopy and femtosecond dynamics of type-II CdSe/ZnTe core-shell semiconductor synthesized via the CdO precursor

Abstract

CdSe/ZnTe type-II quantum dots (QDs) synthesized via the CdO precursor are reported. Spectroscopic and femtosecond dynamic measurements reveal that the rate of photoinduced electron/hole spatial separation decreases with increases in the size of the core, and it is independent of the thickness of the shell in the CdSe/ZnTe QDs. The results are consistent with the binding strength of the electron and hole confined at the center of CdSe. The correlation between the core/shell size and the electron/hole spatial separation rate resolved in this study may provide valuable information for applications where rapid photoinduced carrier separation followed by charge transfer into a matrix or electrode is crucial, such as in photovoltaic devices.