Zinc complex-based hole transporting material for perovskite solar cell applications

Developing hole-transport materials (HTMs) with high hole mobility is critical for constructing efficient perovskite solar cells (PSCs). We present a design strategy for improving hole mobility and PSC performance using a stable zinc complex-based HTM BPZ23. Compared to its non-metal counterpart (BP21), the BPZ23 demonstrated a 59.42% increase in hole mobility, resulting in a good perovskite layer with reduced trap-assisted recombination. As a result, the power conversion efficiency of the fabricated inverted PSC using BPZ23 is up to 19.75%, which is one of the highest reported for any transition metal complex-based HTM employed in inverted PSC. This research demonstrates a simple and efficient method for increasing hole mobility in HTMs and improving the photovoltaic performance of PSCs.