巯基丙酸分子对CdSe核壳量子点和ZnO纳米粒子薄膜之间电荷转移的影响

Abstract

The effect of mercaptopropionic acid(MPA) molecules on the charge transfer process from the quantum dots to ZnO nanocrystal films was studied in this paper by the steady-state and time-resolved photoluminescence spectroscopy.The obtained high efficiently photoluminescent CdSe-core CdS/ZnS-multishell quantum dots with few defects are air stable in quantum dot based devices.Three samples were prepared to make the measurements of time-resolved photoluminescence spectra,CdSe quantum dots film,CdSe quantum dots spun cast on ZnO nanocrystal film(CdSe/ZnO),and MPA molecules linked CdSe quantum dots and ZnO nanocrystal film(CdSe/MPA/ZnO).The shortening of photoluminescence life times of CdSe quantum dots deposited on ZnO nanocrystal films with and without MPA molecules indicated the electron transfer process happened in the interface between CdSe quantum dots and ZnO nanocrystals.But the decreased rate of electron transfer from CdSe quantum dots to ZnO nanocrystal films with MPA molecules was found,compared to the electron transfer rate of the CdSe/ZnO sample.Considering the fact that MPA molecules did not improve the charge transfer process from CdSe quantum dots to ZnO nanocrystal films,it was indicated that the MPA molecules was not a good choice in CdSe quantum dot sensitized solar cell.The experimental result suggested that the direct adsorption of CdSe quantum dots on metal oxide nanocrystal films would obtain quantum dot sensitized solar cell with higher power conversion efficiency.