Structure, band gap and energy level modulations for obtaining efficient materials in inverted polymer solar cells

► Two new D-A polymers composed of BDT as donor and thiadiazolo[3,4-c] pyridine as acceptor were designed and synthesized. ► Through structure, band-gap and energy level modulations, we obtained materials with excellent photovoltaic properties. ► The optimized inverted polymer solar cells exhibit high power conversion efficiencies of 4.84% and 5.11%.