Optimization of annealing temperature on the formation CZTSe absorber layer

In the present work, we studied the optimization of annealing temperature on the formation of Cu 2 ZnSnSe 4 (CZTSe) thin films and its impact on the film properties. The CZTSe films were deposited on Mo/SLG substrate by the thermal evaporation method. All the elements of the compound were deposited in the stack using its pellets. After the successful deposition of the films, the composition of the as deposited film was measured, then it was proceeded further for two steps annealing. The annealing parameter is one of the crucial steps for obtaining good quality kesterite-based absorber layer. In the present work, we have utilized two-step annealing to achieve the absorber layer suitable for device fabrication. The annealing in Se atmosphere were carried out at 230 °C for 10 min in first step followed by another 10 min annealing in second step with a temperature variation from 430 to 490 °C. The final temperature was varied to investigate the influence of annealing temperature on the absorber layer (CZTSe) film properties and its optimization. The films annealed between 470 and 490 °C are showing better structural, optical, electrical and morphological properties for further processing.