Theoretical study on organic dyes with tunable π-spacers for dye-sensitized solar cells: Inspired by the organic polymer photovoltaics

Abstract

We present the theoretical investigation on tuning π-spacers in D-π-A organic dyes for dye-sensitized solar cells (DSSCs). The validity of three series of conjugate units (12 types) conventionally used in polymer photovoltaics are utilized as the π-spacers of organic dyes. Our results indicate that the extension of π conjugation can efficiently improve the absorption intensity. The absorption spectra red-shifts is because the increased π-spacers significantly destabilize the highest occupied molecular orbital level, whereas the lowest unoccupied molecular orbital level has negligible changed. Our simulation is expected to assist the design high performance dyes for dye-sensitized solar cells applications.