Waterborne Acrylic Resin-Modified PEDOT:PSS as a Hole-Transporting Layer for Silicon/Organic Solar Cells with Improved Efficiency and Stability

Si/PEDOT:PSS heterojunction solar cells (HSCs) are of great interest to researchers due to their low cost and simple process, but the hygroscopicity of polymer poly(3,4- ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS) leads to poor stability of such devices, limiting the possibility of their further commercialization. In this research, the stability and power conversion efficiency (PCE) of Si/PEDOT:PSS HSCs were improved by doping waterborne acrylic resin (WA) in PEDOT:PSS. The experimental results show that the surface of WA-doped PEDOT:PSS films has successfully changed from hydrophilic to hydrophobic, and the stability of solar cells prepared from these films in the air has been significantly improved. The WA-doped device retains more than 80% of its initial PCE after 200 h of storage in air, whereas the corresponding undoped device has failed. Unlike general research reports, this work also provides stability data of devices at -12, 80, 120 degrees C, and ultraviolet (UV) illumination, respectively. The results show that the device achieved an optimal PCE of 13.37% when the WA doping concentration was 0.3 wt %; devices with high stability and high PCE are achieved.