Sulfurization of Electrodeposited Sb/Cu Precursors for CuSbS2: Potential Absorber Materials for Thin-Film Solar Cells

CuSbS2, as a direct bandgap semiconductor, is a promising candidate for fabricating flexible thin-film solar cells due to its low grain growth temperature (300 degrees C-450 degrees C). Uniform and highly crystalline CuSbS2 thin films are crucial to improving device performance. However, uniform CuSbS2 is difficult to obtain during electrodeposition and post-sulfurization due to the dendritic deposition of Cu on Mo substrates. In this study, Sb/Cu layers were sequentially pulse electrodeposited on Mo substrates. By adjusting the pulse parameters, smooth and uniform Sb layers were prepared on Mo, and a flat Cu layer was obtained on Sb without any dendritic clusters. A two-step annealing process was employed to fabricate CuSbS2 thin films. The effects of temperature on phases and morphologies were investigated. CuSbS2 thin films with good crystallinity were obtained at 360 degrees C. As the annealing temperature increased, the crystallinity of the films decreased. The CuSbS2 phase transformed into a Cu3SbS4 phase with the temperature increase to 400 degrees C. Finally, a 0.90% efficient solar cell was obtained using the CuSbS2 thin films annealed at 360 degrees C.

Automated summary

CuSbS2 has promising potential for fabricating flexible thin-film solar cells due to its direct bandgap and low grain growth temperature. In this study, uniform and highly crystalline CuSbS2 thin films were successfully obtained by adjusting the pulse parameters and employing a two-step annealing process, leading to a solar cell with an efficiency of 0.90%.