Research progress on D-A-D type hole transporting materials for perovskite solar cells

Perovskite solar cells (PSCs) have attracted wide attention due to their advantages such as rapidly improving photoelectric conversion efficiency, low fabrication cost and facile solution processing techniques. Hole transporting material (HTM) is an important component in PSCs, which is responsible for hole extraction and preventing charge recombination, can improve the performance and stability of PSCs. Organic small molecule hole transporting materials based on linear donor-acceptor-donor (D-A-D) configuration exhibit simple structure and facile synthesis. In addition, the introduction of electron withdrawing groups can low the energy level of highest occupied molecular orbital (HOMO) and improve the stability of the material. And the linear D-A-D configuration is beneficial to the enhancement of intramolecular charge transfer, which improve the hole mobility. The application of linear D-A-D hole transporting materials in PSCs is reviewed since 2009. Meanwhile, the effects of molecular structure of hole transporting materials on the photoelectric conversion efficiency and device stability of PSCs are introduced. Finally, the feature research on D-A-D HTMs is presented. © 2021, Editorial Office of FINE CHEMICALS. All right reserved.