Perovskite-silicon tandem solar cells with bilayer interface passivation

Abstract

Two-terminal monolithic perovskite-silicon tandem solar cells demonstrate huge advantages in power conversion efficiency (PCE) compared to their respective single-junction counterparts^1,2. However, suppressing interfacial recombination at the wide-bandgap perovskite/electron transport layer interface, without compromising its superior charge transport performance, remains a significant challenge for perovskite-silicon tandem cells^3,4. By exploiting the nanoscale discretely distributed LiF ultrathin layer followed by an additional deposition of diammonium diiodide molecule, we have devised a bilayer intertwined passivation strategy that combines efficient electron extraction with further suppression of nonradiative recombination. We constructed perovskite-silicon tandem devices on double-side textured Czochralski (CZ)-based silicon heterojunction cell, which featured a mildly-textured front surface and a heavily-textured rear surface, leading to simultaneously enhanced photocurrent and uncompromised rear passivation. The resulting perovskite-silicon tandem achieved an independently certified stabilized PCE of 33.89%, accompanied by an impressive fill factor (FF) of 83.0% and an open-circuit voltage (V_oc) of nearly 1.97 volts. To our knowledge, this represents the first reported certified efficiency of a two-junction tandem solar cell exceeding the single-junction Shockley-Queisser limit of 33.7%.