Dual energy antenna for efficient dye-sensitized solar cells

Abstract

A novel 4-(dicyanomethylene)-2-methyl-6-[p-(dimethylamino) styryl]-4H-pyran (DCM)-based organic dye with a heteroleptic dual-electron donor was designed, and its electronic and optical properties were investigated theoretically for dye-sensitized solar cells (DSSCs). We designed three dyes with triphenylamine (T) and phenoxazine (P) moieties on each side of a DCM-based organic dye (D); namely, TPDPT, TPDTP, and PTDTP. In this study, heteroleptic TPDTP dye was compared with the homoleptic dyes (TPDPT and PTDTP). The absorption spectrum of the dyes showed different forms because of the different energy levels of the molecular orbital (MO) of each dye and intramolecular energy transfer. It was shown that the energy antenna group created an additional absorption band around 430nm and caused a cascading two-electron process aiding the charge-separation process. Absorption Band 1 (around 640nm) and Band 2 (around 520nm) showed that PD and TD, respectively. It was expected that the TPDTD dye with the heteroleptic dual donor would perform competitively compared to the other dyes with homoleptic dual donors in terms of conversion efficiency in DSSCs