Fused-Ring Acceptors with Asymmetric Side Chains for High-Performance Thick-Film Organic Solar Cells

Abstract

A kind of new fused-ring electron acceptor, IDT-OB, bearing asymmetric side chains, is synthesized for high-efficiency thick-film organic solar cells. The introduction of asymmetric side chains can increase the solubility of acceptor molecules, enable the acceptor molecules to pack closely in a dislocated way, and form favorable phase separation when blended with PBDB-T. As expected, PBDB-T:IDT-OB-based devices exhibit high and balanced hole and electron mobility and give a high power conversion efficiency (PCE) of 10.12%. More importantly, the IDT-OB-based devices are not very sensitive to the film thickness, a PCE of 9.17% can still be obtained even the thickness of active layer is up to 210 nm.

A new fused-ring electron acceptor (IDT-OB), bearing asymmetric side chains, is facilely synthesized for high-efficiency thick-film organic solar cells. The asymmetric structure makes it easier to form ideal phase separation when blended with a polymer donor. Power conversion efficiencies of 10.12% and 8.57% are obtained with the active-layer thicknesses of 130 and 320 nm, respectively.

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