Spray-coated perovskite solar cells fabricated on carbon fibre-reinforced polymer substrates

Carbon fibre-reinforced polymers (CFRPs) combine high strength and elastic modulus with low weight, and are thus an important material within the automobile and aviation industries. Combining high performance perovskite solar cells (PSCs) with CFRP substrates presents an opportunity to create structural materials that also generate power. Here such mobile power applications require the use of devices having a high specific power in which both the efficiency and the weight of the solar cell is of critical importance. Here, we discuss the fabrication of n-i-p PSCs via ultrasonic spray coating on CFRP substrates. Our devices yield a stabilised maximum power conversion efficiency (PCE) of 14.0 %, corresponding to a specific power of 26.0 W g⁻¹. We also spray-coat PSCs onto dome-shaped CFRP substrates having a maximum PCE of 12.3 %, equivalent to a specific power of 22.8 W g⁻¹. Importantly, we subject devices to low cycle mechanical fatigue testing, repeatedly applying a load of 50 N, with devices retaining 100 % of their prestressed PCE after 25 stress cycles. This is the first demonstration of curved, rigid, CFRP based PSCs that can bear an appreciable mechanical load, making them suitable for mobile power applications.