Designing of π‐Bridge for Metal Free Dye‐Sensitized Solar Cell and Optoelectronic Properties: An ab initio DFT Perspective

Abstract

We have designed a series of donor‐π‐acceptor (D‐π‐A) based metal‐free organic dyes to improve the power conversion efficiency of dye‐sensitized solar cells (DSSCs) and optoelectronic properties. Density functional theory (DFT) and time‐dependent density functional theory (TD‐DFT) simulations have been performed to calculate the electronic and optical properties. The reduction of band gap is observed from 2.33 eV to 1.60 eV when we have strategically figure out the suitable π‐bridge. The band gaps 1.53 eV were observed with strong donor group. The ground and excited state oxidation potential, normal dipole moment, light harvesting efficiency, maximum absorption wavelength and electron injection properties were calculated for the designed dyes. Upon the screening of the π‐bridge, we have substituted the reference triphenylamine (TPA) donor group with other best‐known donor. The cyanoacrylic acid group was chosen as the acceptor group for designed dye molecules.The simulated absorption spectra show a bathochromic shift from 435 nm to 817 nm that infers the effect of such variation of the π‐bridging group. The rational designing of high‐performance organic‐based dye sensitizer molecule embark on the scientific community towards the advancement of renewable energy technologies