Non-fullerene based photovoltaic materials for solar cell applications: DFT-based analysis and interpretation

Abstract

In solar cells, the development of small organic donor molecules (SODMs) remains a big challenge. The four new small organic molecules (TTHL1 to TTHL4) have been tailored for the non-fullerene-based molecules. The End-capped alteration of acceptors of recently synthesized donor molecule BPF3T-C8 is done with efficient acceptor units. The DFT and TD-DFT have been employed at the CAM-B3LYP method with 6-31G** basis set. The designed molecules exhibited excellent photovoltaic and optoelectronic properties than the reference one. Minimization of the band-gap with nearly infrared region in the spectrum is noted for donor molecules. High open-circuit voltage in tailored molecules concerning PC61BM is also noted. Lower values of excitation, as well as binding energies in the SODMs, expressed easy dissociation and shifting of charge density in the excited state. The mobility of holes is also associated with the designed molecules. In the end, we recommended (based on the above-mentioned analyses) fullerene/non-fullerene combination for the active layer of solar cell applications with enhanced power conversion efficiency PCE.