Foldable Hole-Transporting Materials for Merging Electronic States between Defective and Perfect Perovskite Sites.

Defective and perfect sites naturally exist within electronic semiconductors, and considerable efforts to reduce defects to improve the performance of electronic devices, especially in hybrid organic-inorganic perovskites (ABX ), have been undertaken. Herein, foldable hole transporting materials (HTMs) were developed, and extend the wavefunctions of A-site cations of perovskite which as hybridized electronic states link the trap states (defective site) and valance band edge (perfect site) between the naturally defective and perfect sites of perovskite surface, finally converting the discrete trap states of perovskite as the continuous valance band to reduce the trap recombination. Tailoring the foldability of the HTMs tunes the wavefunctions between defective and perfect surface sites, allowing the power conversion efficiency of a small cell to reach 23.22% and that of a mini-module (6.5×7 cm , active area = 30.24 cm ) to get as high as 21.71% with a fill factor of 81%, the highest value reported for non-spiro-OMeTAD-based perovskite solar modules. This article is protected by copyright. All rights reserved.