Benzodithiophenedione-based polymers: recent advances in organic photovoltaics
Bing Zheng, Lijun Huo, Yongfang Li
Abstract
Abstract Over the past 20 years, significant progress has been made in organic photovoltaics (OPVs) due to its advantages of being cost-effective, being lightweight, and having flexible manufacturability. The optical-active layer of OPVs consists of a p -type polymer as the donor and an n -type small molecule as the acceptor. An efficient design strategy of a polymer donor is based on an alternating electron-donating unit (D) and an electron-accepting unit (A). Among numerous electron-accepting units, an emerging annelated thiophene of benzodithiophenedione (BDD) has exhibited a distinguished photovoltaic performance because of its planar molecular structure, low-lying highest occupied molecular orbit (HOMO) level and good self-assembly property. In this review article, we summarize the most recent developments in BDD-based photovoltaic materials. Special attention is paid to the chemical structure-property relationships, such as the absorption, bandgap, energy levels, mobilities, and photovoltaic performances. The empirical regularities and perspectives on the future development of BDD-based photovoltaic materials are included.