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. In this review, the development of inverted perovskite solar cells (IPSCs) is briefly introduced first. Next, the recent intensive progress in organic hole-transporting materials including organic small molecules and conjugated conductive polymers for high-performance IPSCs are discussed in detail. The prospective for further development of IPSCs are outlined including developing novel hole-transporting materials and fabricating techniques. image