Aging of quinoxaline-based polymer solar cells under UV-free white light

Abstract

Quinoxaline (Qx) exhibits remarkable properties that can be tuned by changing the length of side chains and the structure of the aromatic rings in the conjugated side chains. This common electron-deficient building block has been used in various donor–acceptor (D–A) conjugated polymers. Qx-based polymers show excellent power conversion efficiency when combined with fullerene and non-fullerene acceptors. In this work, the photostability of two different Qx-based organic solar cells with PCBM and ITIC as acceptors were studied. To determine the stability of the solar cells, devices underwent laboratory weathering tests. Current–voltage (I–V) measurements were periodically conducted on the devices under UV-free white light from LEDs in accelerated aging experiments according to the ISOS protocol L1, where the excitation density was kept equivalent to AM 1.5 G. The burn-in time, stabilized lifetime, as well as lifetime energy yield (LEY) were evaluated.