Effect of annealing temperature on p-n junction formation in Cu2SnS3thin-film solar cells fabricated via the co-evaporation of elemental precursors

Abstract

Cu2SnS3 (CTS) thin-film solar cells were fabricated by the co-evaporation of the precursors, and the effect of annealing in N2 atmosphere on their photovoltaic properties was investigated by varying the annealing temperature after the chemical bath deposition of CdS. The characteristics of the solar cells improved as the annealing temperature was increased in the 250 °C-275 °C range (annealing time: 30 min). However, annealing temperatures exceeding 275 °C caused the deterioration of the device characteristics. Therefore, annealing in the 250 °C-275 °C range after CdS deposition is important for forming an optimum p-n junction at the CTS/CdS interface for manufacturing the CTS solar cells evaluated in this study. The best-performing solar cell fabricated using a CTS film annealed at 275 °C after CdS deposition exhibited an open circuit voltage of 0.181 V, with a short circuit current density of 20.9 mA cm-2, fill factor of 0.462, and power conversion efficiency of 1.74%.