Highly Performance Flexible Polymer Solar Cells by Flipping the Bilayer Film of Ag Nanowires and Polyvinyl Alcohol on Polyethylene Terephthalate as Transparent Conductive Electrodes

Smooth and flexible Ag nanowire (AgNW) transparent conductive electrodes have been realized by successively spin-coating AgNWs and polyvinyl alcohol (PVA) dispersions on the smooth glass surface and then flipping the bilayer film of AgNWs and PVA on the top of polyethylene terephthalate (PET) (PET/flip-AgNWs). As a result, the root mean square of the flipping-AgNW film was only 3.68 nm as low as the indium tin oxide (ITO) electrode on PET. The square resistance and transmittance of the PET/flip-AgNW film reached 15 Ω/sq and 77% at 550-nm wavelength, respectively. The square resistance of the PET/flip-AgNW film remained unchanged after 1000 bending. The power conversion efficiency of inversed polymer solar cells (PSCs) increased from 4.21% for PET/ITO to 4.72% for PET/flip-AgNWs. This facile flipping-AgNW on a flexible substrate route provides a new method for manufacturing and tailing flexible PSCs.