Title: Poly(3‐hexylthiophene)/Gold Nanorod Composites as Efficient Hole‐Transporting Materials for Perovskite Solar Cells
Abstract: Poly(3‐hexylthiophene)/gold nanorod (P3HT/AuNR) composites are developed and introduced as hole‐transporting materials (HTMs) to fabricate mixed‐ion perovskite solar cells (PSCs). The highest power conversion efficiency of the optimized devices based on the composite HTM reaches up to 16.88%, which is an increase of 26% from that of a pristine P3HT‐based device (13.40%). The enhanced performance can be attributed to the increased crystallinity of P3HT induced by the addition of AuNRs in the polymer matrix and the localized surface plasmon resonance effect of AuNRs, which lead to higher carrier mobility and increased light utilization efficiency. This work provides a comprehensive understanding of the effect of plasmonic AuNRs in PSCs application and a useful method to further improve the performance of PSCs.