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 (${\mathrm{V}}_{Si}$), Si+P divacancy (${\mathrm{V}}_{SiP}$), and substituting one P atom by one Si atom (${\mathrm{Si}}_P$) magnetize significantly SiP monolayer. Herein, total magnetic moments between 1.00 and 2.00 ${\mu }_B$ are obtained ${\mathrm{V}}_{Si}$ ${\mathrm{V}}_{SiP}$ ${\mathrm{Si}}_P$. In contrast, no magnetism is induced by single P vacancy (${\mathrm{V}}_P$), substituting one Si atom by one P atom (${\mathrm{P}}_{Si}$), and exchanging pair Si-P positions ($\mathrm{Si}\leftrightarrow \mathrm{P}$). Moreover, significant magnetization of SiP monolayer is also achieved by doping with single Li and Cu atoms (${\mathrm{Li}}_{Si}$ and ${\mathrm{Cu}}_{Si}$), as well as pair of Li and Cu atoms (${\mathrm{pLi}}_{Si}$ and ${\mathrm{pCu}}_{Si}$). Total magnetic moments between 0.84 and 1.42 ${\mu }_B$ are obtained. Interestingly, the half-metallicity is observed in ${\mathrm{Li}}_{Si}$ and ${\mathrm{Cu}}_{Si}$ 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 ${\mu }_B$ 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.

中文翻译：

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六角形 SiP 单层中的点缺陷：电子和磁性特性的系统研究


在这项工作中，提出了点缺陷来改变 SiP 单层的电子和磁性特性。原始单层是一种非磁性半导体二维材料，根据 PBE(HSE06) 泛函预测，其能隙为 1.52(2.21) eV。单Si空位( ${\mathrm{V}}_{Si}$ )、Si+P双空位( ${\mathrm{V}}_{SiP}$ )和一个P原子被一个Si原子取代( ${\mathrm{Si}}_P$ )显着磁化SiP单层。这里，获得1.00和2.00之间的总磁矩 ${\mu }_B$ ${\mathrm{V}}_{Si}$ ${\mathrm{V}}_{SiP}$ ${\mathrm{Si}}_P$ 。相反，单个 P 空位 ( ${\mathrm{V}}_P$ )、用一个 P 原子取代一个 Si 原子 ( ${\mathrm{P}}_{Si}$ ) 以及交换对 Si-P 位置 ( $\mathrm{Si}\leftrightarrow \mathrm{P}$ ）。此外，SiP单层的显着磁化还可以通过掺杂单个Li和Cu原子（ ${\mathrm{Li}}_{Si}$ 和 ${\mathrm{Cu}}_{Si}$ ）以及一对Li和Cu原子（ ${\mathrm{pLi}}_{Si}$ ）。获得的总磁矩在 0.84 和 1.42 ${\mu }_B$ 之间。有趣的是，在 ${\mathrm{Li}}_{Si}$ 和 ${\mathrm{Cu}}_{Si}$ 系统中观察到半金属性。当取代 P 原子时，F、Cl 和 Br 杂质显着降低了 SiP 单层带隙，保留了其非磁性性质。相比之下，通过掺杂I原子获得了1.26 ${\mu }_B$ 的总磁矩。本文提出的结果可能会引入缺陷和掺杂的 SiP 系统作为自旋电子和光电应用的潜在 2D 候选系统。