Increase in the efficiency and stability of large-area flexible organic photovoltaic modules via improved electrical contact

Large-area flexible organic photovoltaic modules suffer from electrical shunt and poor electrical contact between adjacent subcells, causing efficiency and stability losses. Here we improve the performance of large-area flexible organic photovoltaic modules through suppressing electrical shunt and improving electrical contact. We embed large-area silver nanowire electrodes into polymer substrates to reduce surface roughness and therefore to suppress electrical shunt. We deposit chromium and silver lines between adjacent subcells to improve electrical contact. We show that chromium suppresses the aggregation of the silver film, increasing its laser fluence tolerance and retaining its conductance under thermal annealing, mechanical bending and illumination. These improvements enhance the photovoltaic efficiency and illumination stability of the flexible organic photovoltaic modules. Large-area flexible modules achieve certified efficiencies of 14.04% (active area: 41 cm2) and 13.10% (active area: 370 cm2, with an open-circuit voltage of 103.51 V) and retain 90.4 +/- 2.3% of the initial efficiency after continuous illumination for 912 hours. Organic solar modules suffer from poor electrical contacts. Lu et al. embed the silver electrode into a polymer matrix and add chromium to enhance its electrical contact, achieving improved stability and a 14.04% efficiency on flexible modules with an active area of 41 cm2.