Design of “push-pull” p-type quinoid-based organic dyes with near-IR absorption: A density function theory study

Abstract

Based on an experimentally synthesized p-type dye QT-1, we screened and designed a series of quinoid-based “push-pull” dyes SPL401 - SPL407 by modifying the π-conjugated linker for ptype dye-sensitized solar cells (p-type DSSC). Further, we systematically calculated their electronic and optical properties by using the density functional theory (DFT) and the time-dependent DFT (TDDFT). The results indicate that compared to QT-1, SPL406 and SPL407, which have not only smaller energy gaps, higher oscillator strength f increased by 70% and 80%, and 141 nm and 110 nm redshifts, respectively, but also a broader absorption spectrum covering the entire visible range to the near-IR region of 1200 nm, may be the most promising candidates among SPL401 - SPL407 for p-type organic sensitizers.