Two-dimensional carbon nitride (2DCN) nanosheets: Tuning of novel electronic and magnetic properties by hydrogenation, atom substitution and defect engineering

Abstract

By employing first-principles calculations within the framework of density functional theory, we investigated the structural, electronic, and magnetic properties of graphene and various two-dimensional carbon-nitride (2DNC) nanosheets. The different 2DCN gives rise to diverse electronic properties such as metals (C 3 N 2 ), semimetals (C 4 N and C 9 N 4 ), half-metals (C 4 N 3 ), ferromagnetic-metals (C 9 N 7 ), semiconductors (C 2 N, C 3 N, C 3 N 4 , C 6 N 6 , and C 6 N 8 ), spin-glass semiconductors (C 10 N 9 and C 14 N 12 ), and insulators (C 2 N 2 ). Furthermore, the effects of adsorption and substitution of hydrogen atoms as well as N-vacancy defects on the electronic and magnetic properties are systematically studied. The introduction of point defects, including N vacancies, interstitial H impurity into graphene and different 2DCN crystals, results in very different band structures. Defect engineering leads to the discovery of potentially exotic properties that make 2DCN interesting for future investigations and emerging technological applications with precisely tailored properties. These properties can be useful for applications in various fields such as catalysis, energy storage, nanoelectronic devices, spintronics, optoelectronics, and nanosensors.

As2S3, As2Se3 and As2Te3 nanosheets: superstretchable semiconductors with anisotropic carrier mobilities and optical properties

“…Consequently, the VBM energetically shifts upward and CBM moves downward resulting in smaller band gaps than their monolayer counterparts. In the future studies, the effects of mechanical straining, defects and impurities [51][52][53][54][55][56][57][58] can be studied on engineering of the electronic properties of these novel 2D systems.…”

Oxygen Vacancies in the Single Layer of Ti2CO2 MXene: Effects of Gating Voltage, Mechanical Strain, and Atomic Impurities

“…Several approaches have been considered to change the electronic structure of 2DM, such as substitutional doping, defect engineering, application of an electric field or strain, surface functionalization by adatoms, and altering the edge states. [ 37–78 ]…”

DFT-Guided Design and Fabrication of Carbon-Nitride-Based Materials for Energy Storage Devices: A Review

“…The nature of the nitrogen and its percentage concentration has been proven to impact the electronic configuration and characteristic of the carbon nitride for different applications. The classification of carbon nitrides is often based on the carbon to nitrogen content (i.e., the C/N ratio) which is often associated with the degree of surface defects in their structure [ 11 ]. The carbon nitrides discussed in this review are categorized based on the dominant N species in their crystalline structure.…”