Theoretical evaluation of chemical substitutions along the main chain of poly(3-hexylthienylene-vinylene) for solar cell applications

Abstract

In order to improve the efficiency of bulk-heterojunction organic solar cells, one can try to optimize the active layer through the use of new materials that provide improvements in the parameters that influence the final efficiency of a device. The use of chemical substitutions in organic materials already used in these devices seems to be an efficient methodology to obtain new materials with better intrinsic properties. Based on this idea, in this work is investigated theoretically, by methods of electronic structure calculation, a set of 143 poly(3-hexylthienylene-vinylene) (P3HTV) derivatives for application in active layers of organic solar cells as electron donor materials; the chemical modifications were performed on the thiophene ring and the vinyl segment of P3HTV. The results show that it is possible to obtain several new derivatives with better optical and electronic properties than those of P3HTV. The derivative substituted with trifluoromethyl on the vinyl segment is one of the most promising for use in active layers, when combined with phenyl-C61-butyric-acid-methyl-ester as electron acceptor material. An equation to predict the electronic properties of P3HTV derivatives when using more than one chemical substitution is also proposed, which is corroborated by the theoretical calculations. © 2017 Society of Chemical Industry.