Understanding the influence of alkyl-chains and hetero-atom (C, S, O) doped electron-acceptor fullerene-free benzothiazole for application in organic solar cell: first principle perception

• Published in: Optical and quantum electronics 2022-11, Vol.54 (11), Article 681
• Main Authors: Louis, Hitler, Eno, Ededet A., Timothy, Rawlings A., Agwamba, Ernest C., Unimuke, Tomsmith O., Bukie, Paul T., Chukwudubem, Ifeatu E., Offiong, Offiong E.
• Format: Article
• Language: English
• Subjects: Chains; Characterization and Evaluation of Materials; Chemical bonds; Circuits; Computer Communication Networks; Density functional theory; Electrical Engineering; Electronic devices; Energy gap; First principles; Fullerenes; Lasers; Molecular orbitals; Optical Devices; Optics; Photonics; Photovoltaic cells; Physics; Physics and Astronomy; Quantum chemistry; Short circuit currents; Solar cells
• ISSN: 0306-8919; 1572-817X
• DOI: 10.1007/s11082-022-04074-z

Due to tremendous effort in the design of low-band-gap materials, fullerene-free organic solar cells exhibit excellent photovoltaic performances as compared to fullerene compounds. However, the theoretical modelling of wide-band-gap materials through material engineering to significantly enhance the photovoltaic properties remains a challenge. This research work focuses on the influence of heteroatoms (C, O, S) and the alkyl chain length (R = 2, 4, 6) on electron-acceptor fullerene-free benzothiazole material for improved efficiency of photovoltaic cell devices. The electronic excitation, frontier molecular orbitals, natural bond orbital, and photovoltaic properties have been discussed based on quantum chemical density functional theory calculations using the B3LYP/6-311 +  + G (d,p) method. The HOMO–LUMO energy gap analysis revealed that O-atom doped benzothiazoles have higher reactivity relative to the “C” and “S” doped structures and the reactivity increases as the alkyl chain length increases. The photovoltaic results revealed the S-substituted benzothiazole has the highest light-harvesting efficiency and short-circuit current density ( Jsc ) of 0.9361 and 6.1026 respectively. This demonstrates the absorption and power converting potential of the S-doped benzothiazole relative to the “C” and “O” series dyes for application in organic solar cells.