Dopant‐Free Hole‐Transporting Materials for Stable and Efficient Perovskite Solar Cells

Molecularly engineered novel dopant-free hole-transporting materials for perovskite solar cells (PSCs) combined with mixed-perovskite (FAPbI₃ )_0.85 (MAPbBr₃ )_0.15 (MA: CH₃ NH₃⁺ , FA: NH=CHNH₃⁺ ) that exhibit an excellent power conversion efficiency of 18.9% under AM 1.5 conditions are investigated. The mobilities of FA-CN, and TPA-CN are determined to be 1.2 × 10^-4 cm² V^-1 s^-1 and 1.1 × 10^-4 cm² V^-1 s^-1 , respectively. Exceptional stability up to 500 h is measured with the PSC based on FA-CN. Additionally, it is found that the maximum power output collected after 1300 h remained 65% of its initial value. This opens up new avenue for efficient and stable PSCs exploring new materials as alternatives to Spiro-OMeTAD.