Production of Cu2Sn(S,Se)3 thin films and investigation of device properties

In this study, ternary compounds Cu2SnS3 (CTS), Cu2Sn(SSe)3 (CTSSe) and Cu2SnSe3 (CTSe) thin films were prepared by two-stage process. In the first stage, the Cu2Sn precursor layer was deposited on the glass substrate by dip coating method. Then, sulfurization/selenization process of precursors was performed via Rapid Thermal Processing at 525 °C, 550 °C and 575 °C temperatures. Structural, optical and electrical characterizations of synthesized thin films have been performed and the effect of sulfurization/selenization temperature on properties of CT(S,Se) thin films was investigated. For the second part of the study, the p-CT(S,Se) semiconductor thin films reacted at 550 °C were selected for device fabrication due to more promising properties amongst the other samples. Al/n-Si/p-CT(S,Se)/Mo heterojunctions structure was formed and electrical characterizations were performed. X-ray diffraction patterns and Raman spectra of the samples showed that both glass/p-CT(S,Se) and n-Si/P-CT(S,Se) thin films had a monoclinic structure as a dominant phase and additionally some secondary phases were also observed. According to the data obtained from the dV/dln(I)-I graph, it was determined that the sample with the closest ideal diode value among the diodes produced was p-CTSe (n=2.87). It was observed that the selenium contribution reduced the series resistance (Rs) value in CT(S,Se) thin films from 8.27102 Ω to 2.42102 Ω. While two band edge transitions were observed in the CTS thin film produced on glass substrate at 525 °C, a single band edge transition was observed in the CTS thin films produced on n-Si wafer. The carrier concentration values obtained from the capacitance-voltage measurements were found 2.701018 cm3, 3.501018 cm3 ve 5.501018 cm3 for n-Si/p-CTS, n-Si/p-CTSSe, n-Si/p-CTSe structures, respectively.