A Hot Carrier Perovskite Solar Cell with Efficiency Exceeding 27% Enabled by Ultrafast Hot Hole Transfer with Phthalocyanine Derivatives

Hot carrier solar cells could achieve efficiencies exceeding the Shockley-Queisser limit by collecting hot carriers before they cool down. With the hot-phonon bottleneck effect, hot carrier collection may be favorable at high carrier densities in concentrator photovoltaics. In this work, utilizing the excellent thermal stability of a phthalocyanine (Pc) hole transport layer (HTL), we constructed a hot hole collecting HTL. A methylthiotriphenylamine-based SMePc achieved an extraction velocity of 78 900 cm s-1, corresponding to a collecting distance of ~79 nm. With this HTL, an efficiency of 24.95% and certified efficiency of 24.43% are achieved under 1 sun illumination with over 3000 h operational stability in N2 (60 degrees C) and over 1000 h at 85 degrees C. With a solar concentrator, an increase in open-circuit voltage (VOC) above the theoretical cold carrier line is observed, and a record efficiency of 27.30% is achieved under 5.9 sun illumination for a single-junction perovskite solar cell. Our strategy demonstrated the potential application of high-efficiency hot carrier solar cells.