2, Sichuan University, Chengdu, , China
Perovskite solar cells (PSCs) emerging as the most promising next-generation photovoltaic devices have been received great attention. In PSC device, admittedly, Spiro-OMeTAD is the most widely used hole-transporting material (HTM). However, the pristine Spiro-OMeTAD suffers from low hole mobility and conductivity, which requires chemical dopants (Li-TFSI and tBP) to increase conductivity thereby improving power conversion efficiency (PCE). Discouragingly, such dopants not only induce deleterious effects on stability but also significantly affect the hysteresis of PSCs. In this study, F4-TCNQ was introduced into Spiro-OMeTAD as an alternative dopant to replace the widely used Li-TFSI and tBP. By optimizing the doping concentration of F4-TCNQ, the PSC based on 1.5 mol% F4-TCNQ doped Spiro-OMeTAD exhibited the best PCE, which reached about 91% of the PSC based on the Spiro-OMeTAD doped by state-of-the-art Li-TFSI and tBP. Moreover, the PSC based on F4-TCNQ doped Spiro-OMeTAD showed lower hysteresis and better stability. This work not only offers a promising dopant for Spiro-OMeTAD, but also provides a viable approach to address the challenges of hysteresis and instability.