Proceedings of International Conference on Perovskite and Organic Photovoltaics and Optoelectronics (IPEROP19)
Publication date: 23rd October 2018
Rapid progress of organic-inorganic perovskite solar cells (PSCs) has attracted numerous attention and the power conversion efficiency (PCE) is boosted beyond 23.0%1-2 within several years. The flexible PSCs (fPSCs) are regarded as a promising candidate of next-generation photovoltaics in light weight and bendable devices. However, the photovoltaic performance of fPSCs is still far behind those of rigid substrate’s devices. A large hysteresis is also observed, especially in the fPSCs using metal oxide electron transport materials (ETMs)3. Moreover, the bending durability of fPSCs using metal oxide ETMs can not satisfy the requirement for industrial applications4.
In this work, we successfully demonstrated a facile solution process using SnO2 nano-particle as the ETM for fPSCs on Cs0.05(MA0.17FA0.83)0.95Pb(I0.83Br0.17)3 perovskite photoactive film. Figure 1a shows the current-density and voltage (J-V) curves of the fPSCs on active area of 0.1 and 1.0 cm2. Both fPSCs exhibit a superior PCE of 17.1 and 16.2% with negligible hysteresis, respectively. And, these fPSCs also show high stabilized power output of 17.0 and 15.9%, respectively. Moreover, the fPSCs exhibit excellent bending durability of about 80% compared with the initial PCE even after harsh bending testing with 2000 bending cycles at fixed bending radius of 4 and 9 mm, as shown in Figure 1b. The grains’ boundaries of SnO2 film provide a possibility of the reduction of bending stress for fPSCs, therefore, the SnO2 based fPSCs can maintain superior bending durability. The outstanding performance of SnO2 as an excellent ETM for fPSCs will be discussed in detailed.