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

Abstract

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 PC 60BM or PC 70BM as acceptor materials. The highest level of performance of OPVs optimized at TSP-T11:PC 70BM (weight ratios of 1:4) with thicknesses of 68 nm exhibited an open circuit voltage ( V oc) of 0.75 V, a short circuit current ( J sc) 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 cm 2 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.