Fine-Tuning of the Electronic and Optical Properties of Dodecabenzocoronene through Boron and Nitrogen Doping: A DFT Insight

Abstract

Nanographene provides a wide range of possibilities in graphene engineering for future applications due to the higher degrees of configurational freedom with the electronic parameters that may also be continuous or discrete, depending on the intended application. Therefore, the optical and electronic properties of nanographene are of substantial technological interest. Moreover, doping of graphene with heteroatoms (B, P, N, and S, etc.) alters their chemical and electronic characteristics which are suitable for the economical construction of optoelectronic devices. Herein, geometric, electronic, and optical properties of nanographene are evaluated as a function of the nature and position of dopant. Three different nanographene including coronene, hexabenzocoronene (HBC), and dodecabenzocoronene (DBC) are considered for doping (N and B as dopants) in this study with the key focus on DBC-doped systems. For any dopant number, all possible dopant sites are studied except edge position in order to avoid the edge effect. Frontier molecular orbital (FMO) analysis is performed to evaluate the perturbations in electronic characteristics of doped nanographene. A decrease in energy gap is seen for all doped systems. Natural bond orbital (NBO) analysis indicates that doping of boron (B) and nitrogen (N) results in variation in distribution of charges over the nanographene surfaces. The density of states (DOS) analysis reveals that Fermi level ([Formula: see text] is shifted for all B- and N-doped systems. The UV-visible (UV-Vis) absorption spectra are computed to evaluate the changes in the intensity and maximum adsorption wavelength ([Formula: see text] in all doped DBC. Various chemical reactivity descriptors are also evaluated which reveal the degree of stability and chemical reactivity of doped systems. The results indicate that multiple B and N atoms doping offers a new possibility for fine-tuning of electronic and optical properties of nanographene at atomic level, thus providing guidance in development of future advanced optoelectronic devices.