Planar mixed halide perovskite-PCBM solar cells on flexible glass substrates processed at low temperature without ITO

Abstract

Thin film mixed halide perovskite absorber solar cells in a planar device structure are fabricated on a flexible glass substrate. A low temperature solution process is described in which instead of indium tin oxide on flexible glass, a transparent conductive PEDOT:PSS electrode of high electrical conductivity formed by formic acid treatment is effectively used. The photon harvesting strategy uses back surface reflection to enhance photoabsorption in the perovskite. Power conversion efficiency is 5.12±0.08% for rigid glass and 4.37±0.03% for flexible glass substrates. Perovskite solar cells fabricated on flexible glass exhibit mechanical flexibility under repeated bending while maintaining device performance.