Air-stable triarylamine-based amorphous polymer as donor material for bulk-heterojunction organic solar cells

A new air-stable triarylamine-based amorphous polymer, TSP-T11, which consists of thiophene and triarylamine units, can be successfully utilized to fabricate bulk-heterojunction organic photovoltaics (OPVs) using PC60BM or PC70BM as acceptor materials. The highest level of performance of OPVs optimized at TSP-T11:PC70BM (weight ratios of 1:4) with thicknesses of 68 nm exhibited an open circuit voltage (Voc) of 0.75 V, a short circuit current (Jsc) of 8.03 mA cm−2, and a power-conversion efficiency (PCE) of 2.22% under simulated air mass 1.5 solar irradiation at 100 mW cm−2. Although TSP-T11 has a lower hole mobility (1.5×10−4 cm2 V−1 s−1) than P3HT, the use of amorphous film of TSP-T11 as a donor material for OPVs offers advantages over the use of polycrystalline film of P3HT in terms of its air-stability and pinhole-free homogeneous morphology.