Design of MoO3 Porous Back Contact for High Efficiency CZTSSe Thin-film Solar Cells

The introduction of in-situ anodized MoO3 porous arrays with tailored structural parameters as the rear interface contact has a positive impact on enhancing the solar cell performance. The optimized device efficiency increased from 6.31% to 9.00% (in reference to molybdenum-based cells), resulting in a 32% increase in JSC and a 64% increase in FF. The results indicate that at a 10V oxidation voltage, the MoO3 pore size is relatively larger, facilitating the formation of a well-interpenetrating structure and contact interface with CZTSSe. In turn, assists in carrier interface separation and transfer, effectively suppressing the recombination of separated carriers. It extends carrier lifetime, reduces band tailing effects, and lowers urbach energy, thus improving the overall performance of CZTSSe devices.