2,3-Diphenylthieno[3,4-<i>b</i>]pyrazines as Hole-Transporting Materials for Stable, High-Performance Perovskite Solar Cells
Shakil N. Afraj, Ding Zheng, Arulmozhi Velusamy, Weijun Ke, Shelby A. Cuthriell, Xiaohua Zhang, Yao Chen, Chenjian Lin, Jen‐Shyang Ni, Michael R. Wasielewski, Wei Huang, Junsheng Yu, Chun-Huang Pan, Richard D. Schaller, Ming-Chou Chen, Mercouri G. Kanatzidis, Antonio Facchetti, Tobin J. Marks
Abstract
High-performance and durable perovskite solar cells (PSCs) have advanced rapidly, enabled in part by the development of superior interfacial hole-transporting layers (HTLs). Here, a new series of 2,3-diphenylthieno[3,4-b]pyrazine (DPTP)-based small molecules containing bis- and tetrakis-triphenyl amino donors (1–3) was synthesized from simple, low-cost, and readily available starting materials. The matched energy levels, ideal surface topographies, high hole mobilities of 8.57 × 10–4 cm2 V–1 S–1, and stable chemical structures of DPTP-4D (3) make it an effective hole-transporting material, delivering a PCE of 20.18% with high environmental, thermal, and light-soaking stability when compared to the reference HTL materials, doped Spiro-OMeTAD and PTAA in PSC n-i-p planar devices. Overall, these DPTP-based molecules are promising HTM candidates for the fabrication of stable PSCs.