Enhanced Performance and Stability of Perovskite Solar Cells with Ag–Cu–Zn Alloy Electrodes

Though the common metal electrode‐based perovskite solar cells (PSCs) have achieved a power conversion efficiency (PCE) of >25%, they also play a crucial role in accelerating the degradation of the cells. This study investigates phase transition engineering in Ag electrodes via Cu and Zn alloying, transforming from a cubic to a tetragonal phase. These alloyed electrodes are then thermally deposited as back electrodes in Cs 0.05 (FA 0.83 MA 0.17 ) 0.95 Pb(I 0.83 Br 0.17 ) 3 ‐based PSCs. The work functions of these alloy electrodes closely match those of the spiro‐OMeTAD HTL, effectively suppressing nonradiative carrier recombination at the interface and reducing the energy barrier for carrier transport. Further, the Ag–Cu–Zn alloys exhibit high resistance to corrosion and good adhesion on the hole‐transport material layer compared to a layer of Ag. As a result, PSCs incorporating an optimized Ag 0.875 Cu 0.120 Zn 0.005 electrode achieve a maximum PCE of 19.02%, surpassing the 18.71% efficiency observed in PSCs with a conventional Ag electrode. Moreover, this electrode demonstrates remarkable durability, sustaining operational integrity for 460 h for the PSCs stored in an N 2 glove box, in contrast to the 320 h for cells with Ag electrodes. These advancements may lead to the realization of cost‐effective, durable, and efficient solar energy conversion systems.