Stabilizing Fullerene for Burn-in-Free and Stable Perovskite Solar Cells under Ultraviolet Preconditioning and Light Soaking.

Hang, Pengjie; Xie, Jiangsheng; Kan, Chenxia; Li, Biao; Zhang, Yiqiang; Gao, Pingqi; Yang, Deren; Yu, Xuegong · Adv Mater · 2021

basic_science · Level V

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Abstract

It is crucial to make perovskite solar cells sustainable and have a stable operation under natural light soaking before they become commercially acceptable. Herein, a small amount of the small molecule bathophenanthroline (Bphen) is introduced into [6,6]-phenyl-C<sub>61</sub> -butyric acid methyl ester and it is found that Bphen can stabilize the C<sub>60</sub> -cage well through formation of much more thermodynamically stable charge-transfer complexes. Such a strengthened complex is used as an interlayer at the in-light perovskite/SnO<sub>2</sub> side to achieve a champion device with efficiency of 23.09% (certified 22.85%). Most importantly, the stability of the resulting devices can be close to meeting the requirements of the International Electrotechnical Commission 61215 standard under simulated UV preconditioning and light-soaking testing. They can retain over 95% and 92% of their initial efficiencies after 1100 h UV irradiation and 1000 h continuous illumination of maximum power point tracking at 60 °C, respectively.