Computational study of X-doped hexagonal boron nitride (h-BN): structural and electronic properties (X = P, S, O, F, Cl)

Characteristics and performance of layered two-dimensional materials under doping engineering

In recent years, doping engineering, which is widely studied in theoretical and experimental research, is an effective means to regulate the crystal structure and physical properties of two-dimensional materials and expand their application potential. Based on different types of element dopings, different 2D materials show different properties and applications. In this paper, the characteristics and performance of rich layered 2D materials under different types of doped elements are comprehensively reviewed. Firstly, 2D materials are classified according to their crystal structures. Secondly, conventional experimental methods of charge doping and heterogeneous atom substitution doping are summarized. Finally, on the basis of various theoretical research results, the properties of several typical 2D material representatives under charge doping and different kinds of atom substitution doping as well as the inspiration and expansion of doping systems for the development of related fields are discussed. Through this review, researchers can fully understand and grasp the regulation rules of different doping engineering on the properties of layered 2D materials with different crystal structures. It provides theoretical guidance for further improving and optimizing the physical properties of 2D materials, improving and enriching the relevant experimental research and device application development.

Engineering the Optoelectronic Properties of 2D Hexagonal Boron Nitride Monolayer Films by Sulfur Substitutional Doping

Tuning the optical and electrical properties of two-dimensional (2D) hexagonal boron nitride (hBN) is critical for its successful application in optoelectronics. Herein, we report a new methodology to significantly enhance the optoelectronic properties of hBN monolayers by substitutionally doping with sulfur (S) on a molten Au substrate using chemical vapor deposition. The S atoms are more geometrically and energetically favorable to be doped in the N sites than in the B sites of hBN, and the S 3p orbitals hybridize with the B 2p orbitals, forming a new conduction band edge that narrows its band gap. The band edge positions change with the doping concentration of S atoms. The conductivity increases up to 1.5 times and enhances the optoelectronic properties, compared to pristine hBN. A photodetector made of a 2D S-doped hBN film shows an extended wavelength response from 260 to 280 nm and a 50 times increase in its photocurrent and responsivity with light illumination at 280 nm. These enhancements are mainly due to the improved light absorption and increased electrical conductivity through doping with sulfur. This S-doped hBN monolayer film can be used in the next-generation electronics, optoelectronics, and spintronics.

Computational study of electronic properties of X-doped hexagonal boron nitride (h-BN): X = (Li, Be, Al, C, Si)

The structural and electronic properties of h-BN sheet implanted with X atoms (X = lithium (Li), beryllium (Be), aluminum (Al), carbon (C), and silicon (Si)) have been investigated to tune its band gap to amend its insulating behavior toward semiconducting material employing density functional theory (DFT). It has been observed that on replacing nitrogen or boron (N/B) atom with impurity atom, several impurity levels appear in band gap dividing big gap into small energy gaps, albeit to a different extent, depending upon the dopant element and substitutional site. The lowest value of band gap falls as low as 2.27 eV as compared to 4.63 eV of pristine h-BN in addition to the appearance of states at the Fermi level. Additionally; geometrical, interaction of foreign elements with the host material, and stability issues are discussed. These results are affable for its usage in transistor-based devices and to explore its new applications in high-power electronic and optoelectronic devices.