Preparation of vanadium diselenide thin films and their application in CdTe solar cells

Vanadium diselenide thin films were prepared by electron beam evaporation. The properties of vanadium diselenide thin films were investigated using X-ray diffraction, scanning electron microscope, transmission spectra, electrical and Hall measurements. To further investigate the application of vanadium diselenide thin films, device performance in CdTe solar cells with a vanadium diselenide layer was also studied. The results indicate that vanadium diselenide thin films had a stable hexagonal structure after annealing. The thin films were p-type semiconductor materials with the high work function and high carrier concentration. Vanadium diselenide thin films could form a good ohmic contact to CdTe solar cells. Thus, cell performance was greatly improved when introduced a vanadium diselenide buffer layer. •VSe2 was prepared by electron beam evaporation.•VSe2 was a p-type material with the high work function and high carrier concentration.•VSe2 was used as a Cu-free buffer layer in CdTe solar cells.•Performance of CdTe solar cells was improved.