Radiation-processed perovskite solar cells with fullerene-enhanced performance and stability

Summary Radiation-processed strategy is compatible with scalable manufacturing of perovskite solar cells (PSCs). Herein, we show such radiation-processed planar negative-intrinsic-positive (n-i-p) PSCs, which integrate radiation-processed electron/hole transporting layers (ETLs/HTLs) and light-absorbing layers (LALs). Infrared radiation annealing enables SnO2 ETLs with a conductivity comparable to those annealed by hot plates and renders perovskite LALs with pure perovskite phase and prominent (111) orientation. With the benefit of chlorofullerene C60Cl6 additives for LALs, PSCs based on Li/Co-bis(trifluoromethanesulphonyl)imide (TFSI)-doped spiro-OMeTAD HTLs exhibit a champion efficiency of 22% and excellent photostability, retaining 82% of their efficiencies after 504 h of illumination. With the solar-radiation-treated gadolinium-endohedral fullerene Gd@C82-doped spiro-OMeTAD, the radiation-processed PSCs show stable efficiencies of more than 20% and decent shelf stability, maintaining 92% of their efficiencies after 1,008 h in air. Based on that prototype of radiation-processed PSCs, this work implies that cost-efficient fullerene additives/dopants are beneficial to the feasible radiation strategy for fabricating efficient and stable PSCs.