Tris-isopropyl-sily-ethynyl anthracene based small molecules for organic solar cells with efficient photovoltaic parameters

Studied four different molecules specified as Rm1, Rm2, Rm3 and Rm4 consist of a central donor core linked through π-bridge with four different end capped acceptors. Results of all these designed molecules were compared with TIPS-anthracene as a reference molecule. All designed molecules have shown good optoelectronics properties such as larger absorption wavelength, lower band gap and suitable pattern of frontier molecular orbital with suitable charger transfer rate. [Display omitted] •Small molecule donors (Rm1-Rm4) have been designed using efficient acceptor moieties.•The designed molecules exhibited good charge mobility and electron coherence.•Photophysical and elctronic properties of designed molecules are very encouraging. Four small molecules (Rm1 to Rm4) based on TIPS-anthracene are designed by linking different end-capped acceptors at terminals of thiophene spacer. Photovoltaic properties are inspected under the concepts of density functional theory (DFT) as well as time-dependent (TD) DFT using the MPW1PW91/6-31G (d,p) method to check maximum absorption, presence, and availability of frontier molecular orbitals (FMOs), solution processability, and charge transport effectiveness in TIPS-anthracene based molecules. Comparative inspection between simulated results of newly studied and reference molecules has given an unclouded picture of the better compatibility of novel organic molecules in solar devices. However, among all the designed molecules, Rm4 and Rm2 have marked better λmax (642.3 nm and 597.2 nm) in chloroform by using IEFPCM model. The Rm2 has the lowest reorganization energy that is λe = 0.0038 eV and λh = 0.0072 eV, therefore, has good charge transferability as compared to other molecules. Similarly, Rm2 (µe = 8.7097 Debye) has the highest dipole moment means the highest crystallinity in solution. While open-circuit voltage (Voc) of donor/acceptor interface (Rm2/ PCBM) has shown the highest value (1.75 V). So, Rm2/ PCBM is preferred for charge transfer analysis to make evidence of charge mobility in this interface which is acknowledge competent. Studied TIPS-anthracene based interface Rm2/ PCBM can be utilized in solar devices owing to efficient photovoltaic parameters.