Solution‐Processed Pure Sulfide Cu<sub>2</sub>(Zn<sub>0.6</sub>Cd<sub>0.4</sub>)SnS<sub>4</sub> Solar Cells with Efficiency 10.8% Using Ultrathin CuO Intermediate Layer
Siarhei Zhuk, T.K.S. Wong, Miloš Petrović, Emmanuel Kymakis, Shreyash Hadke, Stener Lie, Lydia Helena Wong, Prashant Sonar, Avishek Dey, Satheesh Krishnamurthy, Goutam Kumar Dalapati
Abstract
Herein, it is demonstrated that incorporating ultrathin p‐type cupric oxide (CuO) enhances the performance and stability of solution‐processed Cu 2 (Zn 0.6 Cd 0.4 )SnS 4 (CZCTS)/CdS thin film solar cells. In sol–gel CZCTS/CdS thin film solar cells, nanoscale CuO films (4–32 nm) are deposited on top of molybdenum (Mo) by magnetron sputtering and this is used as an intermediate layer (IL). The CuO IL thickness has a significant effect on the short‐circuit current density ( J SC ) in CZCTS/CdS solar cell devices. As a result, a maximum power conversion efficiency (PCE) of 10.77% is measured for the optimized device with 4 nm CuO compared with 10.03% for the reference device without a CuO layer. Furthermore, the stability of the devices is enhanced significantly by incorporating the CuO IL. This work demonstrates that through proper design of the CuO IL thickness, both the back interface quality and optical property of the CZCTS absorber can be tuned to enhance the device performance.