Constructing hole transporting highway for high-efficiency perovskite solar cells

To manufacture stable and efficient perovskite solar cells (PSCs), researchers have focused on developing hole transporting materials (HTMs) with passivation effect and high hole mobility. Here, we report a hole-transporting highway from perovskite absorber to Au electrode constructing with two star-shaped hole transport materials, TP01 and PP01, which has gradient-increase energy level. TP01 hole conductor with triazine core can also successfully passivate the defects of perovskite interface and bends the energy band of perovskite absorber. The dual HTMs by combining TP01 and PP01 enable 59% and 330% increasement of hole mobility for “bare” PP01 and TP01. Finally, by using TP01 as a molecule dopant and PP01 as an HTM, a power conversion efficiency (PCE) of 20.92% is achieved on the champion device and 95% initial PCE is remained after 30 days aging. The work provides an efficient way to enhance the hole mobility for improving the photovoltaic performance of PSCs.