Theoretical studies on organoimido-substituted hexamolybdates dyes for dye-sensitized solar cells (DSSC)

• Published in: Dyes and pigments 2013-11, Vol.99 (2), p.440-446
• Main Authors: Wang, Jing, Li, Hong, Ma, Na-Na, Yan, Li-Kai, Su, Zhong-Min
• Format: Article
• Language: English
• Subjects: Absorption spectrum; Conversion; Density functional theory; Dyes; IPCE; Optimization; Organic–inorganic hybrids; Photovoltaic cells; Polyoxometalates; Solar cells; Spacers; Spectra; π-conjugated bridges
• ISSN: 0143-7208; 1873-3743
• DOI: 10.1016/j.dyepig.2013.05.027

A series of POM-based organic–inorganic hybrids with different π-conjugated bridges are investigated as sensitizers for application in dye-sensitized solar cells (DSSCs). A combination of density functional theory (DFT) and time-dependent DFT (TDDFT) approaches is employed. The effects of π-conjugated spacer size and π-conjugation length on the spectra of designed systems are demonstrated. The results show that the absorption spectra are systematically broadened and red-shifted with increasing sizes of the π-conjugated spacer and the length of π-conjugation. The theoretical examination was performed on the key parameters of incident photon-to-electron conversion efficiency (IPCE), light harvesting efficiency (LHE) and electron injection efficiency (Φinj). The result suggests that system 2 with thieno[3,2-b]thiophene demonstrates a balance of the two crucial factors and may result in the highest IPCE of DSSCs. This study is expected to deepen our understanding of POM-based organic–inorganic hybrid dyes and assist the molecular design of new dyes for the further optimization of DSSCs. [Display omitted] •The novel dyes of POM-based organic–inorganic hybrids were designed for DSSCs.•The absorption spectra of systems were systematically studied.•The electron injection efficiency (Φinj) from dyes to TiO2 was evaluated.•The light harvesting efficiency (LHE) of dyes was assessed.•The incident photon-to-electron conversion efficiency (IPCE) of dyes was assessed.