Molecular design of novel indacenodithiophene‐based organic dyes for efficient dye‐sensitized solar cells applications

Abstract

Indacenodithiophene (IDT)‐based high‐efficiency photovoltaics have received increasing attention recently. This paper reports a density functional theory investigation of the electronic and optical properties of three IDT‐based organic dyes together with the dye/(TiO2)46 interface. In order to enhance the photoelectric properties of IDT dyes, this paper considers two methods for the structure modification of the experimentally reported dye DPInDT (J. Org. Chem. 2011, 76, 8977): the extension of the conjugation length by dithienothiophene as well as the heteroatom substitution of the bridging atoms by electron‐rich nitrogen atoms. Our calculations show that both methods obviously affect the distributions of the molecular orbitals and notably red shift the absorption peaks of around 20 nm, with the former method demonstrating enhanced light harvesting efficiency. The structure modifications proposed also enhance the emission spectrum properties for IDT‐based organic dyes. The calculated ultrafast injection time of electrons from the excited state of IDT dyes to the (TiO2)46 belongs to the femtosecond order of magnitude, and is ideal for efficient photoelectric conversion process in dye‐sensitized solar cells (DSSCs) applications. The IDT dyes designed in this paper have good electronic and spectroscopic properties. This study is expected to provide useful guidance for the development of novel IDT dyes for applications in DSSCs.

End‐substituted thiahelicenes for electronic device applications

“…Continuous growth of research interest in oligothiophene systems is observed due to their wide range of applications as organic photoelectric devices and optical materials. [ 1–4 ] These thiophene‐based materials make significant contributions, especially in the field of light‐emitting diodes, [ 5,6 ] photovoltaics, [ 7,8 ] and organic field‐effect transistors. [ 9,10 ] Stability, suitable highest occupied molecular orbital‐lowest unoccupied molecular orbital (HOMO‐LUMO) energy gap, strong optical absorption in a desired region, and suitable bandgap are among the few requirements of molecular systems for applications as efficient photoelectric devices.…”