Perovskite solar cells based on small molecule hole transporting materials

This review gives an overview of the design and development of perovskite solar cells with a main focus on hole transporting materials (HTMs). The recent advances in metal halide perovskite solar cells surprised the traditional photovoltaic community. A key advance was subsequently made by replacing liquid electrolytes with solid state HTMs like spiro-OMeTAD, which not only improve power conversion efficiency but also enhance the cell stability. As a result, many research groups, including our group, have become involved in the synthesis of new HTMs to optimize the photovoltaic properties of perovskite solar cells (PSCs). The hole transporting materials in perovskite solar cells have received significant attention in recent years as a promising materials capable of developing high performance photovoltaic devices at low cost.