Fabrication and characterization of titanium dioxide/copper indium disulfide solar cells

Copper indium disulfide (CIS)-based solar cells with titanium dioxide (TiO2) were produced on F-doped SnO2 (FTO) by a spin-coating method. The effect of the stacking sequence of the CIS and TiO2 layers on the electronic properties of the solar cells was investigated. A device based on an FTO/CIS/TiO2 structure provided better cell performance compared to that based on an FTO/TiO2/CIS structure. The microstructure of TiO2/CIS was examined using energy dispersive X-ray analysis, X-ray diffraction, and transmission electron microscopy, and the TiO2/CIS solar cells provided bulk heterojunction structures. The energy levels of the present solar cells are also discussed.