Synthesis of A-D-A type quinoxaline-based small molecules for organic photovoltaic cells

Abstract

We have synthesized two acceptor-donor-acceptor (A-D-A) type quinoxaline-based small molecules for organic photovoltaic cells (OPVs). To construct the A-D-A architecture, the electron-accepting quinoxaline derivative (Qx) was attached on both ends of the electron-donating benzodithiophene (BDT) unit via the Stille coupling reaction. After the confirmation of the structural features, the optical and electrochemical characteristics and the photovoltaic properties of the two small molecules were investigated. A typical inverted-type device with the configuration of ITO/ZnO/small molecules: PC₇₁BM/MoO₃/Ag was fabricated and examined. It has been observed that the performances of OPVs were improved by the incorporation of the additional thiophene linkage between the BDT and Qx moieties. Therefore, this study can provide insights into the design and structure–property correlation of quinoxaline-based organic small molecules for OPVs