Perovskite Photovoltaics on Roll-to-Roll Coated Ultra-Thin Glass as Exceptional Flexible Power-Generator for Indoors

Abstract

We present a big leap in performance for indoor photovoltaics by developing flexible perovskite solar cells (PSCs) on ultra-thin flexible glass (FG). We manufactured roll-to-roll ITO-coated FG with excellent transmittance (> 80%) and sheet resistance (13 Ω/square ) and impressive bendability. Rather than resulting in planar structures which worked best for thick rigid glass-based cells, optimized PSCs on the ultrathin FG incorporate instead a mesoporous scaffold over thin SnO2 compact layers that significantly contributed to the achievement of breakthrough power conversion efficiencies (PCEs) of 20.6% (16.7 m W cm-2 power density), and 22.6% (35.0 m W cm-2) under 200 and 400 lx LED illumination respectively. These represent the highest reported for any existing flexible photovoltaic technology tested in indoors, surpassing by a huge 60-90% margin the prior best-performing flexible PSCs, as a result of significantly lower recombination currents and series resistances, higher fill factors and shunt resistances. Ultra-thin glass flexible PSCs can become the key enabling technology for the indoor electronics of the future, being lightweight, conformable and highly efficient.