Configurable Organic Charge Carriers toward Stable Perovskite Photovoltaics

Due to their solution processability and unique photoelectric characteristics, perovskite solar cells (PSCs) have shown considerable promise in the area of renewable energy. Although their power conversion efficiency (PCE) has risen from 3.8% to 25.7% in only a few years, their short lifetime and high material prices continue to be key roadblocks to commercial viability. Charge transporting materials (CTMs), such as hole/electron transporting materials, are critical components in PSCs because they not only govern hole or electron extraction and transporting from the perovskite layer to the electrodes but also protect the perovskite from direct contact with the ambient environment. CTMs are split into two types: inorganic CTMs (ICTMs) and organic CTMs (OCTMs). Because of their inexpensive prices, well-adjusted energy levels, and low temperature solution-processed features, OCTMs have been more frequently explored and employed than ICTMs. Various forms of OCTMs with more straightforward synthetic pathways and better performance have been thoroughly researched. Recent achievements in the development of OCTMs will be discussed and evaluated on a molecular level in this study, which will include a systematic categorization of OCTMs based on molecular functionalization techniques. In order to achieve highly efficient and stable PSCs, we will present insights on the structure-property relationship in the design of OCTMs as well as device stability. We hope that this analysis will serve as a comprehensive reference to molecular design guidelines for various types of OCTMs, spurring greater research toward designing highly efficient and OCTMs for stable PSCs.