Realizing a colorful polymer solar cell with high color purity via a metal alloy-dielectric–metal alloy electrode

Abstract

Building-integrated photovoltaics (BIPV) system is one of the potential emerging technologies in this decade due to not only its promises on harvesting solar energy to mitigate the power required in buildings but also its capability of offering vast aesthetics to buildings. Compared to various kinds of solar cells, cost-effective polymer solar cells (PSCs) are preferable candidates to serve the purposes of BIPVs effectively. In this work, we have demonstrated an efficient PSC based on a blend of donor polymer, PM6, and non-fullerene acceptor, Y6, as an active layer and a metal-dielectric-metal electrode. The proposed PSC exhibits color tunability (blue, green, and red) straightforwardly through variation in the thickness (75 nm, 95 nm, and 125 nm, respectively) of the dielectric layer consisting of organic molecules, 1,4,5,8,9,11-Hexaazatriphenylene-hexacarbonitrile (HAT-CN) sandwiched between 30 nm thick silver (Ag) metal or copper (Cu)–Ag or aluminum (Al)–Ag metal alloys. The optimized PSCs with blue, green, and red aesthetics exhibit power conversion efficiencies (PCE) of 13.62%, 13.30%, and 13.43%, which is comparable to that (13.77%) of the reference PSC fabricated with 100 nm thick Al:Ag electrode. The outstanding device performance of the proposed PSCs, i.e., the ability to provide desired aesthetics without compromising PCEs of the devices has been thoroughly investigated by physical and electrical characterization. The results show a cost-effective route to fabricate an efficient colorful BIPV for successful commercialization.