Structural and Electrical Properties of Chemical-Solution-Deposited CdS Films for Solar Cells

The structural and electrical properties of CdS films prepared by chemical-solution deposition have been studied. As-deposited films have about 0.4 µm thickness, a grain size of about 0.3 µm and consist of the coalesence of columnar structure. The dark resistivity of more than 104 Ωcm of as-deposited films decreased by about three orders of magnitude to about 10 Ωcm upon annealing in N2 atmosphere at 300–500°C for 20 minutes. The decrease in resistivity was caused by an increase in electron concentration. The resistivity of annealed CdS films was low enough to use as a window layer of thin-film solar cells.