Fabrication of patterned CdS/TiO2 heterojunction by wettability template-assisted electrodeposition

A wettability template-assisted process was applied to selectively deposit cadmium sulfide (CdS) nanospheres on TiO2 nanotube layers to form uniformly coupled CdS/TiO2 semiconductor heterojunction micropatterns. The effect of deposition time on the size and morphology of the as-prepared CdS/TiO2 array patterns was investigated. It is shown that the CdS nanocrystals with a highly ordered, hierarchically porous structure in nano-micro dual scales could be selectively grown within the superhydrophilic regions. The patterned CdS/TiO2 heterojunctions have demonstrated enhanced photo-response under both UV and visible light irradiation. This novel template patterning technique, which is based on wettability contrast, can be applied to a broad range of technological areas, such as sensor arrays and optoelectronic devices. (C) 2010 Elsevier B.V. All rights reserved.