Speaker: Prof. TIAN He, Academician
Institute of Fine Chemicals
East China University of Science & Technology
Title: Dyes Molecular Engineering for Efficient Dye-sensitized Solar Cells
Date: Thursday, Dec 26th, 2013
Time: 9:30 am
Venue: Conference Room B, 909-1F
Dye-sensitized solar cells are currently attracting a great deal of both scientific and industrial interest, owing to their grand potential of supplying clean electricity at a preferable performance/price ratio. In recent years, structure design and optimization of dye sensitizers have achieved considerable progress. Absorption spectra of the dyes can be effectively broadened through introducing new low-band-gap groups such as benzothiadiazole, diketopyrrolopyrrole and bithiazole as π conjugation, strong electron donors like aromatic amine, indoline or designing D-D-π-A structure, thereby improve short-circuit photocurrent density. Meanwhile, by introducing long alkyl chains, designing cone-shaped dye molecule, the dyes can form tense resistant layers on TiO2 surface and inhibit injected electrons in TiO2 film recombine with I3- in the electrolyte, thus improve open-circuit voltage of the cells. However, these design roles are focusing on optimizing electron donors and conjugations, and acceptors, mainly for carboxylic acid and rhodanine-3-acetic, are rarely investigated. In addition, stability tests show that detachment of dyes from TiO2 film and oxidation of nitrile group under irradiation still exists, leading to decline of the cells. This will greatly influence the future industrial application of dye-sensitized solar cells. Therefore, in addition to find more matching electron donors and conjugations, how to design near-infrared sensitizers with stable and strong acceptors firmly bonding to TiO2 surface is in eyebrow nimble.