Semitransparent polymer solar cells with 12.37% efficiency and 18.6% average visible transmittance.

A series of opaque and semitransparent polymer solar cells (PSCs) were fabricated with PM6:Y6 as active layers, and 100 nm Al or 1 nm Au/(20, 15, 10 nm) Ag layer as electrode, respectively. The power conversion efficiency (PCE) of opaque PSCs arrives to 15.83% based on the optimized active layer with a thickness of 100 nm, resulting from the well-balanced photon harvesting and charge collection. Meanwhile, the 100 nm PM6:Y6 blend film exhibits a 50.5% average visible transmittance (AVT), which has great potential in preparing efficient semitransparent PSCs. The semitransparent electrodes were fabricated with 1 nm Au and different thick Ag layers, exhibiting a relatively high transmittance in visible light range and relatively low transmittance in near infrared range. The PCE and AVT of the semitransparent PSCs can be adjusted from 14.20% to 12.37% and from 8.9% to 18.6% along with Ag layer thickness decreasing from 20 to 10 nm, respectively, which are impressive values among the reported semitransparent PSCs.