Deposition of the N-type (CdS) Thin Film on the P-type (CuInSe2) Thin Film as a Buffer for CIS Solar Cell

The N-type CdS thin films have been deposited on the P-type CulnSe2 thin film on glass substrate by using dc sputtering technique. The purpose of this research is to obtain the influence of the CulnSe2/CdS on the type conductivity of thin film. To obtain the optimum of CdS thin film, the sputtering parameters were variate. The time deposition is 30, 60, 90 and 120 min, the gas pressure is at 1.1 x 10-1; 1.2 x 10-1; 1.3 x 10-1 and 1.4 x 10-1 Torr and other parameters were kept constant at 200 ℃, 3 kV and 40 mA. The resistance and type conductivity were measured by four point probe. The minimum resistance was achieved at the condition of time deposition 60 min, 1.3 x 10-1Torr of gas pressure, the resistance R 5.14 kΩ with the type of conductivity is N-type. Crystal structure of the layer is oriented at (103), (004) and (200) plane for CuInSe2 layer and (100), (110), (220) plane for CdS layer. From microstructure analysis it was observed that the grains were distributed homogeneously with the thickness of CulnSe2 and CdS layer were in order of 1.0 µm and 0.6 µm. (author)