In-situ self-assembly of hole transport monolayer during crystallization for efficient single-crystal perovskite solar cells
Vishal Yeddu, Khulud Almasabi, Yafeng Xu, Augusto Amaro, Shuang Qiu, Sergey Dayneko, Dongyang Zhang, Parinaz Moazzezi, Christopher Tremblay, Muhammad Naufal Lintangpradipto, Heather L. Buckley, Omar F. Mohammed, Osman M. Bakr, Makhsud I. Saidaminov
Abstract
Single-crystal perovskite solar cells (SC-PSCs) are emerging as a promising technology owing to their intrinsically low defect densities, long carrier diffusion lengths, and enhanced stability compared to their polycrystalline counterpart. However, their performance has been limited by interface-related losses, particularly at the perovskite/charge transport layer, which hinders effective hole extraction and promotes non-radiative recombination. In this work, we introduce a self-assembled monolayer (SAM) deposition strategy that exploits an asymmetric substrate stack configuration during space-confined inverse temperature crystallization (SC-ITC). This configuration triggers an in-situ migration of SAM molecules from the SAM-coated substrate to the uncoated substrate, resulting in a denser and more homogeneous SAM coating than the conventional spin-coating method can achieve. The improved SAM coverage significantly enhances hole extraction. Consequently, our SC-PSCs achieved power conversion efficiency as high as 24.32%.