Enhancing power conversion efficiency and anti-bending ability of flexible perovskite solar cells with PEDOT:PSS:Li hole transport layer
Ziang Xie, Ping Wu, Sen Chen, Shiping Zhang, Li Li, Yili Pei
Abstract
Abstract Power conversion efficiency (PCE) and anti-bending ability of flexible perovskite solar cells (FPSCs) are largely improved, when poly(3,4-ethylenedioxythiophene) polystyrene sulfonate lithium (PEDOT:PSS:Li) fabricated by the two-step annealing method is used as the hole transport layer (HTL). The PCE of the optimized FPSC achieved 16.83%, which is relatively 6.9% larger than that of the control FPSC. The failure bending cycle, N f , was defined to characterize the service life of the FPSCs. The optimized N f achieved 3797, which is 2.6 times the N f of the control FPSC. During the bending process, the PEDOT:PSS:Li layer retarded the cracking of the ITO layer, and extended the service life of the FPSC. The optical and electrical properties, anti-bending ability and storage stability of PEDOT:PSS:Li were investigated. The layer electrical conductivity, σ , achieved 1320.70 S cm −1 . When the bending radius was fixed as 1.0 cm, after 10000 bending cycles, σ remained 1057.90 S cm −1 , or 80.1% of the original value, which exhibits satisfactory anti-bending ability. PEDOT:PSS:Li is very potential to function as the HTL in FPSCs.