Resent Progress in Side-Chain Engineering of Organic Photovoltaic Conjugated Polymer

Abstract

Photovoltaic conjugated polymer materials are composed of π-conjugated backbone and flexible side chains. Their potential advantages of cost-effective production, fabrication on flexible and light weight substrates by roll-to-roll solution processing, capability to be fabricated into flexible devices and reduced environment impact have made them receive consid- erable attention in both academia and industry. In recent years, most of the interest has been directed into the optimization of main chain, while research on side-chain engineering of polymer is relatively few. Initially, side chains have been primarily utilized as solubilizing groups in organic photovoltaic conjugated polymers. However, roles which side chains play are far beyond. Accordingly, it has been found that side chains of organic conjugated polymer have a different impact on polymer absorption, emission, energy level, carrier mobility, nanoscale morphology and interfacial contact. Certainly enough, these findings have profound guiding significance on molecular structure design and optimization, blend microstructure, interfacial morphology, preparation methods and processing technology of device and so on. Moreover, based on ameliorative prepara- tion and processing technology of device, side-chain engineering is deserved to be deeply researched due to their remarkably improved ability to regulate and control blend microstructure, interfacial morphology so as to obtain ideal photovoltaic proper- ties and device performance, the ultimate goal. Thus, as for resent progress in application, in this perspective article, we will present a review on side chain engineering and assess different side chain on the basis of molecular structure design and opti- mization, as well as summarize relevant issues to be solved and related work in our laboratory. Keywords side chain engineering; photovoltaic properties; polymer solar cells; nanoscale morphology