3D Conjugated Hole Transporting Materials for Efficient and Stable Perovskite Solar Cells and Modules

Abstract

The orthogonal structure of the widely used hole transporting material (HTM) Spiro‐OMeTAD imparts isotropic conductivity and excellent film‐forming capability. However, inherently weak intra‐ and inter‐molecular π‐π interactions result in low intrinsic hole mobility. Herein, a novel arylamine derivative, termed FTPE‐ST, with a twist conjugated dibenzo[g,p]chrysene core and coplanar 3,4‐ethylenedioxythiophene (EDOT) as extended donor units, was designed to enhance intra‐ and inter‐molecular π‐π interactions, without compromising on solubility. The 3D configuration provides the material multi‐direction charge transport as well as excellent solubility even in 2‐methylanisole (2‐MA), and its large conjugated delocalization backbone endows the HTM with a high hole mobility (7.2 × 10−4 cm2V−1s−1). Moreover, the sulfur donors in the EDOT units coordinate to lead ions on the perovskite surface, leading to stronger interfacial interactions and the suppression of defects at the perovskite/HTM interface. As a result, perovskite solar cells (PSCs) employing FTPE‐ST as the HTM achieve a champion power conversion efficiency (PCE) of 25.21% with excellent long‐time stability, which is one of the highest PCEs for non‐spiro HTMs in n‐i‐p PSCs. In addition, the excellent film‐forming capacity of the HTM enables the fabrication of FTPE‐ST‐based large‐scale PSCs (1.0 cm2) and modules (29.0 cm2), which achieve PCEs of 24.21% (certificated 24.17%) and 21.27%, respectively.This article is protected by copyright. All rights reserved