Graphical Abstract
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Transparent electrodes based on copper nanowires (Cu NWs) have attracted significant attention owing to their advantages including high optical transmittance, good conductivity, and excellent mechanical flexibility. However, low-cost, high-performance, and environmental friendly solar cells with all-Cu NW electrodes have not been realized until now. Herein, top and bottom transparent electrodes based on Cu NWs with low surface roughness and homogeneous conductivity are fabricated. Then, semi-transparent polymer solar cells (PSCs) with the inverted structure of polyacrylate/Cu NWs/poly(3, 4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT: PSS) (PH1000)/Y-TiO2/poly(3-hexylthiophene): [6, 6]-phenyl-C61-butyric acid 3, 4, 5-tris(octyloxy)benzyl/PEDOT: PSS (4083)/Cu NWs/polyimide/polydimethylsiloxane are constructed; these could absorb light from both sides with a power conversion efficiency reaching 1.97% and 1.85%. Furthermore, the PSCs show an average transmittance of 42% in the visible region, which renders them suitable for some specialized applications such as power-generating windows and building-integrated photovoltaics. The indium tin oxide (ITO)- and noble metal-free PSCs could pave new pathways for fabricating cost-effective semi-transparent PSCs.
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