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In this work, point defects are proposed to modify the electronic and magnetic properties of SiP monolayer. Pristine monolayer is a non‐magnetic semiconductor 2D material with energy gap of 1.52(2.21) eV as predicted by PBE(HSE06) functional. Single Si vacancy (VSi${\rm V}_{Si}$), Si+P divacancy (VSiP${\rm V}_{SiP}$), and substituting one P atom by one Si atom (SiP${\rm Si}_{P}$) magnetize significantly SiP monolayer. Herein, total magnetic moments between 1.00 and 2.00 μB$\mu _{B}$ are obtained VSi${\rm V}_{Si}$VSiP${\rm V}_{SiP}$SiP${\rm Si}_{P}$. In contrast, no magnetism is induced by single P vacancy (VP${\rm V}_{P}$), substituting one Si atom by one P atom (PSi${\rm P}_{Si}$), and exchanging pair Si‐P positions (Si↔P${\rm Si}\leftrightarrow {\rm P}$). Moreover, significant magnetization of SiP monolayer is also achieved by doping with single Li and Cu atoms (LiSi${\rm Li}_{Si}$ and CuSi${\rm Cu}_{Si}$), as well as pair of Li and Cu atoms (pLiSi${\rm pLi}_{Si}$ and pCuSi${\rm pCu}_{Si}$). Total magnetic moments between 0.84 and 1.42 μB$\mu _{B}$ are obtained. Interestingly, the half‐metallicity is observed in LiSi${\rm Li}_{Si}$ and CuSi${\rm Cu}_{Si}$ systems. When substituting P atom, F, Cl, and Br impurities reduce significantly the SiP monolayer bandgap, preserving its non‐magnetic nature. In contrast, a total magnetic moment of 1.26 μB$\mu _{B}$ is obtained by doping with I atom. Results presented herein may introduce the defected and doped SiP systems as prospective 2D candidates for spintronic and optoelectronic applications. [ABSTRACT FROM AUTHOR]

Germanene nanoribbons, a one-dimensional material, have great potential for future technological applications. This research aims to investigate the electro-optical properties of boron-doped germanene nanoribbons with a width of five atoms. The theory used in this study is density functional theory (DFT). The original system is a narrow band gap semiconductor, with a gap size of 0.06eV. The doped configurations, which retain the honeycomb hexagonal structure, are stable and metallic in nature. The introduction of B atoms flattens the configuration, leading to a partial charge shift from Ge to B. The absorption peaks in the 3B and 5B configurations occur in the frequency range less than 500nm, indicating good absorption of visible light, and suggesting possible applications in light-sensitive components. Notably, the real part of the dielectric function’s 0z component is negative, offering immense potential for optical, microwave and communication applications. [ABSTRACT FROM AUTHOR]

In this work, the effects of doping with carbon (C) and silicon (Si) on the electronic and magnetic properties of phosphorus nitride (PN) monolayer are investigated. PN monolayer is stable, exhibiting the semiconductor nature with indirect band gap of 1.81(2.89) eV calculated by standard Perdew–Burke–Ernzerhof (hybrid HSE06) functional. C and Si impurities prefer doping at N and P sublattices, respectively. PN monolayer is slightly magnetized by doping with 25% of C with total magnetic moment of 0.20 μB$\mu _{\text{B}}$. The magnetization is stronger in the remaining cases with total magnetic moments of 1.00 μB$\mu _{\text{B}}$. Magnetic properties are produced mainly by C and Si impurities. In addition, C and Si codoping is also investigated, in which the magnetization depends strongly on the interatomic distance between impurities. Specifically, the inter‐dopant interactions preserve the non‐magnetic nature of PN monolayer, but significantly reduce the energy gap. However, further separating these dopants leads to the emergence of magnetism with total magnetic moment of up to 1.97 μB$\mu _{\text{B}}$. Results may introduce doping‐based effective method to induce feature‐rich electronic and magnetic properties in buckled honeycomb PN monolayer. Such that, the C‐ and Si‐doped PN sheets are recommended for spintronic applications considering their magnetic semiconductor nature. [ABSTRACT FROM AUTHOR]

In this work, the stability, and electronic and magnetic properties of pristine and doped graphene-like ionic NaX (X = F and Cl) monolayers are explored using first-principles calculations. The good stability of NaF and NaCl monolayers is confirmed by phonon dispersion curves and ab initio molecular dynamics simulations. Electronic structure calculations show their insulator nature with large indirect band gaps of 5.43 (7.26) and 5.06 (6.32) eV as calculated with the PBE (HSE06) functional, respectively. In addition, their ionic character is also demonstrated. Furthermore, a doping approach is explored to functionalize NaX monolayers for spintronic applications. For such a goal, IIA- and VIA-group atoms are selected as dopants due to their dissimilar valence electronic configuration as compared with the host atoms. The results indicate the emergence of magnetic semiconductor nature with a total magnetic moment of 1μB. Herein, magnetic properties are produced mainly by the dopant atoms, which induce new middle-gap energy states around the Fermi level. Finally, the effects of codoping the NaF monolayer with Ca and O and NaCl with Ba and O are also examined. Adjacent Ca–O and Ba–O pairs preserve the non-magnetic nature. Further separating dopants leads to the emergence of magnetic semiconductor behavior, with lower magnetization than separate doping. This work introduces new ionic 2D materials for optoelectronic and spintronic applications, contributing to the research effort to find out new 2D multifunctional materials. [ABSTRACT FROM AUTHOR]

Controlling the electronic and magnetic properties of two-dimensional (2D) materials is a key step to make new multifunctional candidates for practical applications. In this work, defects and doping with transition metals (TMs = V, Cr, Mn, and Fe) at Ge sublattices are proposed in order to develop novel features in the hexagonal germanium arsenide (GeAs) monolayer. The pristine GeAs monolayer is a non-magnetic indirect gap semiconductor with an energy gap of 1.20(1.82) eV as provided by PBE(HSE06)-based calculations. A single Ge vacancy metallizes the monolayer, preserving its non-magnetic nature. In contrast, significant magnetization with a total magnetic moment of 1.96 μ B is achieved by a pair of Ge vacancies. Herein, the computed band structures assert the half-metallic behavior of the defective system. Similarly, half-metallicity is also obtained by V, Mn, and Fe doping. Meanwhile, the Cr-doped GeAs monolayer is classified as a diluted magnetic semiconductor 2D system. In these cases, magnetic properties are produced mainly by TM-3d electrons with total magnetic moments between 2.00 and 4.00 μ B . Further, the effects of substituting a pair of Ge atoms with a pair of TM atoms (pTM Ge systems) are also investigated. Results indicate the ferromagnetic half-metallicity of the pV Ge system, meanwhile antiferromagnetic ordering is stable in the remaining cases. In all cases, TM impurities transfer charge to the host GeAs monolayer since they are surrounded by As atoms, which are more electronegative than dopant atoms. Results presented herein may introduce new 2D systems - made from the non-magnetic GeAs monolayer - for spintronic applications with suitable electronic and magnetic features controlled mainly by transition metals., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

Doping has been widely employed to functionalize two-dimensional (2D) materials because of its effectiveness and simplicity. In this work, the electronic and magnetic properties of pristine and doped KF monolayers are investigated using first-principles calculations based on density functional theory (DFT). Phonon dispersion curves and ab initio molecular dynamics (AIMD) snapshots indicate good stability of the pristine material. The band structure shows an insulating behavior of the KF monolayer, with indirect gaps of 4.80 (6.53) eV as determined using the PBE (HSE06) functional. Its ionic character is also confirmed by the valence charge distribution and Bader charge analysis, and is generated by charge transfer from the K-4s orbital to the F-2p orbital. Doping at both anion and cation sites is explored using N/O and Ca/Sr as dopants, respectively, due to their dissimilar valence electronic configuration in comparison with that of the host atoms. It is found that the KF monolayer is significantly magnetized, where total magnetic moments of 2.00 and 1.00 μ B are obtained via N and O/Ca/Sr doping, respectively. Moreover, the appearance of new middle-gap energy states leads to the development of a magnetic semiconductor nature, which is regulated by N-2p, O-2p, Ca-3d, Ca-4s, Sr-4d, and Sr-5s orbitals. Further investigation of codoping indicates that a magnetic-semiconductor nature is preserved, where the synergistic effects of dopants play a key role in the electronic and magnetic properties of the codoped systems. The results presented herein introduce doping as an efficient approach to functionalize the ionic KF monolayer to obtain prospective d 0 spintronic materials, a functionality that is not accounted for by the pristine monolayer., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)