Energy level alignment, electron injection, and charge recombination characteristics in CdS/CdSe cosensitized TiO2 photoelectrode
Journal
Applied Physics Letters
Journal Volume
98
Journal Issue
1
Pages
012101-1 - 012101-3
Date Issued
2011
Author(s)
Abstract
The band-edge levels of CdS-, CdSe-, and CdS/CdSe-sensitized TiO2 electrodes were determined by ultraviolet photoelectron spectroscopy (UPS) to explore the reason leading to the high performance of the TiO2/CdS/CdSe electrode. The obtained UPS results show the stepwise energy level in the TiO2/CdS/CdSe electrode, indicating energy level alignment occurrence between CdS and CdSe in the TiO2/CdS/CdSe. Time-resolved photoluminescence and open-circuit photovoltage decay experiments reveal that the photogenerated electrons in the TiO2/CdS/CdSe have higher injection efficiency, but lower recombination rate to the electrolyte, attributable to the stepwise structure of band-edge levels constructed by the effect of the energy level alignment.
SDGs
Publisher
American Institute of Physics
Type
journal article