Vanadium Oxide‐Modified Triphenylamine‐Based Hole‐Transport Layer for Highly Reproducible and Efficient Inverted Perovskite Solar Cells

Abstract

Inverted perovskite solar cells (PSCs) often employ triphenylamine-based materials, such as poly(triarylamine) (PTAA), as hole-transporting layer (HTL). However, the high hydrophobic PTAA usually induces unsatisfactory perovskite growth, resulting in inferior efficiency and reproducibility. Herein, the vanadium oxide (VOx) film is introduced to modify hydrophobic PTAA layer and establish a hydrophilic surface for high-quality perovskite film due to the decreased surface tension with improved perovskite solution spread, nucleation, and growth. The PSCs based on PTAA/VOx HTL exhibit high power conversion efficiency up to 18.9% with a sharp increase in comparison to the 16.5% of the control device. Moreover, the reproducibility is also significantly improved, showing a much smaller standard deviation of 1.75 for 40 devices compared to the control devices of 3.64. This work demonstrates that the introduction of VOx is a promising approach in producing high-quality perovskite films on poor-wetting PTAA layer for high-performance inverted PSCs.