Recent Progress in Inorganic Hole Transport Materials for Efficient and Stable Perovskite Solar Cells

Abstract

Organic–inorganic hybrid perovskite solar cells (PSCs) are considered as one of the most promising emerging photovoltaics with outstanding performance. However, the commonly used organic hole transport materials (HTMs) suffer from heat-, light-, and bias-induced degradation along with defect diffusion and hygroscopic properties. To resolve these issues in conventional HTMs, inorganic materials with superior chemical stability, high carrier mobility, and low cost have been developed, demonstrating improved stability under rigorous conditions such as high temperature and long-term illumination. Understanding the properties of alternative inorganic HTMs is of prominent importance to realize more stable and efficient PSCs. This review summarizes the recent progresses in inorganic HTMs adopted in various device architectures, with their remarkable achievements in efficiency and long-term stability.