New progress has been made in the study of two-dimensional conjugated fused ring electron acceptors by Professor Zhan Xiaowei of Peking University

Professor Zhan Xiaowei's research group of Beijing University of technology has made new progress in the research of two-dimensional conjugated (also known as side chain conjugated) fused loop electron acceptor materials for organic solar cells, and the relevant results have been published in adv mater And J am Chem SOC., the top journals in materials and chemistry Zhanxiaowei group introduced the concept of two-dimensional conjugation into the design of new fused ring electron acceptor, and synthesized the first two-dimensional conjugated fused ring electron acceptor material The introduction of two-dimensional conjugated side chain can expand the intramolecular conjugation, thus enhancing and broadening the absorption, which is conducive to increasing the photocurrent of organic solar cells; at the same time, it can also enhance the intermolecular interaction, thus improving the carrier mobility, which is conducive to increasing the photocurrent and filling factor of devices They designed and synthesized a two-dimensional conjugated seven parallel fused ring electron acceptor material itic2 The energy conversion efficiency of single junction two-component solar cells based on itic2 is 11.0%, which is higher than that of one-dimensional conjugated fused ring electron acceptor material with similar structure (8.5%), indicating that two-dimensional conjugation is an effective molecular design strategy to improve the performance of fused ring electron acceptors Work published on adv mater (adv mater 2017, 29, 1702125) In order to further broaden the absorption spectrum of the molecule, they extended the framework of heptagonal fused ring to nine fused ring, and synthesized a pair of isomeric two-dimensional conjugated fused ring electron acceptors fnic1 and fnic2 The effect of isomerization has a significant effect on the optical, electrical, morphological and photovoltaic properties of materials The energy conversion efficiency without reprocessing of the single junction and two-component solar cell devices made of these two isomeric fused ring electron acceptor materials is 10.3% and 13.0%, respectively The energy conversion efficiency of the semi transparent solar cell device is 7.58% - 9.14% (average visible light transmittance 20.2% - 14.7%) and 9.51% - 11.6% (average visible light transmittance 20.3% - 13.6%) respectively 13.0% and 11.6% are the highest energy conversion efficiency of two-component organic solar cells without post-treatment and translucent organic solar cells reported in the literature The work was published in J am Chem SOC (J am Chem SOC 2018, 140, 9140) Wang Jiayu, a doctoral student in Zhan Xiaowei's research group, is the first author of these two papers This series of work is supported by NSFC and so on.