Chiral-structured heterointerfaces enable durable perovskite solar cells.

Duan, Tianwei; You, Shuai; Chen, Min; Yu, Wenjian; Li, Yanyan; Guo, Peijun; Berry, Joseph J; Luther, Joseph M et al. · Science · 2024

basic_science · Level V

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Abstract

Mechanical failure and chemical degradation of device heterointerfaces can strongly influence the long-term stability of perovskite solar cells (PSCs) under thermal cycling and damp heat conditions. We report chirality-mediated interfaces based on <i>R</i>-/<i>S</i>-methylbenzyl-ammonium between the perovskite absorber and electron-transport layer to create an elastic yet strong heterointerface with increased mechanical reliability. This interface harnesses enantiomer-controlled entropy to enhance tolerance to thermal cycling-induced fatigue and material degradation, and a heterochiral arrangement of organic cations leads to closer packing of benzene rings, which enhances chemical stability and charge transfer. The encapsulated PSCs showed retentions of 92% of power-conversion efficiency under a thermal cycling test (-40°C to 85°C; 200 cycles over 1200 hours) and 92% under a damp heat test (85% relative humidity; 85°C; 600 hours).