Solution-Processed Metal-Oxide Nanoparticles to Prevent The Sputtering Damage in Perovskite/Silicon Tandem Solar Cells

Semitransparent perovskite solar cells (ST-PSCs) for tandem applications typically use a buffer layer deposited via atomic layer deposition (ALD) to protect the cell stack from the damage induced by the sputtering of the transparent electrode. Here, we present a simple yet effective solution-processed buffer layer based on metal-oxide nanoparticles to mitigate sputter-induced damage. We exploit this strategy in a monolithic tandem integrating the optimized ST-PSC on a polished front-side/unpolished rear-side p-type silicon heterojunction (SHJ) solar cell. The intrinsic roughness on the backside significantly boosts the absorption, thus suppressing the need for a dedicated texturization step and leading to a final maximum efficiency of 25.3%. Our findings highlight the potential of solution-processed buffer layers as a practical and scalable solution to mitigate the sputtering damage, as well as the potential of silicon wafers with an unpolished rear surface for enhanced photocurrent.