CdS-Sensitized ZnO Nanorod Photoelectrodes : Photoelectrochemistry and Photoinduced Absorption Spectroscopy

Abstract EN

Thin films of ZnO semiconductor nanorods (ZnO-nr) of 6 μm length and thin ZnO nanoparticulate films (ZnO-np) have been prepared and modified with Q-dots CdS for comparison study.

PIA (photoinduced absorption spectroscopy), a multipurpose tool in the study of dye-sensitized solar cells, is used to study a quantum-dot-modified metal-oxide nanostrucutred electrode.

Q-dot CdS-sensitized ZnO-nr (1D network) sensitized photoelectrode has demonstrated best performances in both photoelectrical response (IPCE max = 92%) and broadening response into far visible comparing to ZnO-np-based CdS solar cell.

Preadsorbing ZnO-nr with ZnO-np does not bring further improvement.

Time constant for electron injection into ZnO-nr conduction band was relatively fast decay of 6.5 ms, similar to TiO2-coated CdS, and proves at least a well pore filling of ZnO-nr film by ultrafine CdS particles.

Unidirectional electron transfer mechanistic in ZnO-nr has played a major role in these performances.