Light management in Cu₂ZnSnSe₄ solar cells with ZnO:Al periodic sub-wavelength architectures

This study used a vacuum deposition technique to manufacture Cu₂ZnSnSe₄ (CZTSe) solar cells, providing a scalable and safe manufacturing approach for low-cost, high-performance photovoltaic technology. Additionally, nanoimprint lithography was successfully employed to fabricate two types of periodic sub-wavelength architectures on the surface of CZTSe solar cells, serving as anti-reflective layers and further enhancing their conversion efficiency. The research demonstrates that when the surface architecture of the CZTSe solar cells is Nano-hill, it exhibits superior gradient refractive index and optimal anti-reflective properties, consistent with simulation results. For CZTSe solar cells with this surface architecture, the average reflectance decreased from the pristine 9.86 %–7.34 %, and at an incident light angle of 60°, the reflectance dropped from 17.99 % to 9.53 %, demonstrating the architecture's omnidirectional anti-reflective capability. The periodic sub-wavelength architectures fabricated in this study enhanced the efficiency of the solar cells from 3.68 % to 6.66 %, not only improving conversion efficiency but also showcasing the potential for comprehensive anti-reflective layers, interface repair, and continuous processing. This research not only contributes to optical design but also holds significant importance for the future development of CZTS(Se) technology.