TiO$_{2}$-Loaded WO$_{3}$ Composite Films for Enhancement of Photocurrent Density
Wen-Gui Wang, Li Zhu, Yu-Yan Weng**, Wen Dong**
College of Physics, Optoelectronics and Energy, Collaborative Innovation Center of Suzhou Nano Science and Jiangsu Key Laboratory of Thin Films, Soochow University, Suzhou 215006
Abstract：Titanium dioxide (TiO$_{2}$) loaded tungsten trioxide (WO$_{3}$) composite films are prepared by an E-beam vapor system. Associated with the existence of a heterojunction at the interface of TiO$_{2}$ and WO$_{3}$, the prepared TiO$_{2}$-WO$_{3}$ composite film shows enhanced photocurrent density, four times than the pure WO$_{3}$ film illuminated under xenon lamp, and higher incident-photon-to-current conversion efficiency. By varying the initial TiO$_{2}$ film thickness, such composite structures could be optimized to obtain the highest photocurrent density. We believe that thin TiO$_{2}$ films improve the light response and increase the surface roughness of WO$_{3}$ films. Furthermore, the existence of the heterojunction results in the efficient charge carriers' separation, transfer process, and a lower recombination of electron-hole pairs, which is beneficial for the enhancement of photocurrent density.
2017, Vol. 34 
