Fabrication of Cu-Doped CdS Cell by an All-Evaporation Process and Its Photovoltaic Properties

Abstract

Thin-film photovoltaic cells using a Cu-doped CdS layer have been fabricated by an all-evaporation process. The cells were fabricated by successive deposition of Cu(≃ 10 nm), thin CdS(≃ 0.5 µm), thick CdS(≃ 4 µm) and Al(≃ 0.1 µm) layers on the transparent SnO2:F film of the glass substrate. Deposition conditions such as substrate temperature during each deposition process and the thickness of each layer determine the distribution of Cu in the CdS layer and strongly affect the spectral response and the total efficiency. The conversion efficiency of the best cell was 6.3% for the illumination from the W-lamp. The i-n homojunction model was proposed for the formation of a potential barrier of 0.60∼0.65 eV.