A Comprehensive Review of Organic Hole-Transporting Materials for Highly Efficient and Stable Inverted Perovskite Solar Cells

Inverted perovskite solar cells (IPSCs) have attracted unprecedented attention due to their negligible hysteresis, long-term operational stability, low temperature, and cost-effective fabrication process, as well as wide applications. The power conversion efficiency (PCE) of IPSCs has skyrocketed from 3.9% in 2013 to certified 26.1% in 2023, which is over the certified 25.8% of regular counterpart, benefiting from the emergence of a great number of organic hole-transporting materials (HTM). This review provides an overview of the recent development of organic hole-transporting materials in the efficiency and stability of IPSCs, including organic small molecules and conjugated conductive polymers. The effective strategies for the charge-transport layer and perovskite films of IPSCs are also discussed. Finally, the prospective for further development of IPSCs is outlined, including developing novel hole-transporting materials and fabricating techniques to meet the requirements of commercial application.