Development of Flexible Perovskite Solar Cells toward High Power-to-weight Ratio: From Small Cells to Large Modules

The recent progress of our flexible perovskite solar cells is presented herein. A deformation-free indium tin oxide (ITO) electrode on ultrathin polyethylene naphthalate (PEN) films was developed by combining amorphous and crystalline ITO layers in a bilayer structure. Ultrathin flexible perovskite solar cells on 4 11m PEN were successfully fabricated using the bilayer ITO, achieving a power conversion efficiency (PCE) of 18.2% and a power-to-weight ratio of24 W/g. The large area flexible perovskite solar modules of 20.5 cm
²
on 125 µm thick films and 1 m long solar sheet were also demonstrated. The module achieved PCE of 17.1% and a power-to-weight ratio of 0.50 W/g. The devices demonstrated promise for wearable electronics, internet-of-things applications, and building-integrated photovoltaics (BIPV).