The impact of the nitrogen atom on the optoelectronic, nonlinear optical, and thermodynamic properties of graphene quantum dots derived from dibenzocoronene: A DFT investigation

• Published in: Materials science in semiconductor processing Vol. 180; p. 108583
• Main Authors: Kabé, Christian Gebki, Ottou Abe, M.T., Bouba, Marius Ousmanou, Kabé, Clovis, Nya, Fridolin Tchangnwa, Ndjaka, Jean Marie
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.09.2024
• Subjects: DFT; Graphene quantum dots; Impact of nitrogen; NLO; Optoelectronics; NLO; Impact of nitrogen; Optoelectronics; DFT; Graphene quantum dots
• ISSN: 1369-8001; 1873-4081
• DOI: 10.1016/j.mssp.2024.108583

Because of their potential applications in electricity and photonics, graphene quantum dots (GQDs) with intriguing physical characteristics have attracted a lot of attention. Here we use density functional theory (DFT) with the B3LYP functional associated with the 6–31++G(d,p) basis to explore the effect of the nitrogen atom on the optoelectronic, nonlinear optical, and thermodynamic properties of dibenzocoronene (DBC) isomers. The pristine molecules of the DBC isomers have HOMO-LUMO energy gaps of 3.39 eV (DBCa), 3.39 eV (DBCb) and 3.65 eV (DBCc). Inserting a nitrogen atom into the DBC molecular structure considerably reduces the energy gap between these two orbitals. The materials thus obtained after nitrogen doping are DBCa-N, DBCb-N, and DBCc-N and have respective gap energies of 2.05, 1.80, and 1.65 eV (in other words, less than 3 eV). It can therefore be deduced that the compounds studied will be used as semiconductors in electronics. The static polarizabilities α of the N-doped DBC isomers obtained are 442.960, 443.523, and 455.657 au, respectively, each of these values being 4 times higher than that of the organic reference molecule for non-linear optical properties (para-nitroaniline pNA α = 114.7 au), while the first-order hyperpolarizabilities β obtained are 2689.838, 5572.137, and 12717.472 au, respectively. These values are approximately 2.5, 5, and 12 times higher than those of para-nitroaniline (β = 1072.44 au). Our results confirm that the investigated DBC nitrogen derivatives are good non-linear optical materials for photonics, data storage, dynamic imaging, optical signal processing, and computer systems. All the calculated thermodynamic properties show that the proposed molecules can be easily produced. This manuscript thus stands out as a good compass in the rational design of organic semiconductors for efficient electronic devices.