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

Abstract

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.