Superior Photocurrent of Quantum Dot Sensitized Solar Cells Based on PbS: In/CdS Quantum Dots

Abstract

PbS: In and CdS quantum dots (QDs) are sequentially assembled onto a nanocrystalline TiOfilm to prepare a PbS: In/CdS cosensitized photoelectrode for QD sensitized solar cells (QDSCs). The results show that PbS: In/CdS QDs have exhibited a significant effect in the light harvest and performance of the QDSC. In the cascade structure of the electrode, the reorganization of energy levels between PbS and TiOforms a stepwise structure of band-edge levels which is advantageous to the electron injection into TiO Energy conversion efficiency of 2.3% is achieved with the doped electrode, under the illumination of one sun (AM1.5, 100 mW cm2). Besides, a remarkable short circuit current density (up to 23 mA·cm-2) is achieved in the resulting PbS: In/CdS quantum dot sensitized solar cell, and the related mechanism is discussed.