Department of Physics and Astronomy, KU Leuven, Leuven, 3001, Belgium.
IMEC, Leuven, 3001, Belgium.
Sci Rep. 2023 Jul 17;13(1):11521. doi: 10.1038/s41598-023-37777-8.
Using spin-polarized first-principles calculations based on density functional theory, we study the stability, electronic properties and magnetic behavior induced by hole-doping of two-dimensional (2D) PbBr and HgBr. Although inherently nonmagnetic, these materials can exhibit stable ferromagnetic order when hole-doped at densities above a few 10 cm. We also examined the impact of intrinsic and extrinsic defects on inducing hole-doping and subsequent ferromagnetism. Our findings suggest that p-type doping can be achieved by Pb and Hg vacancies and Br antisites, but the latter behaves as deep acceptors. Among the possible dopants we considered, Li substituting Pb or Hg, and S replacing Br in 2D HgBr, can produce shallow acceptor states near the valence band edges and potentially result in a stable ferromagnetic order in these 2D dibromides.
使用基于密度泛函理论的自旋极化第一性原理计算，我们研究了二维（2D）PbBr 和 HgBr 中掺杂空穴后的稳定性、电子性质和磁行为。尽管这些材料本身是非磁性的，但当掺杂密度高于几个 10cm 时，它们可以表现出稳定的铁磁有序。我们还研究了本征和外禀缺陷对诱导空穴掺杂和随后的铁磁性的影响。我们的研究结果表明，Pb 和 Hg 的空位以及 Br 的反位可以实现 p 型掺杂，但后者表现为深受主。在所考虑的可能掺杂剂中，Li 取代 Pb 或 Hg，以及 S 取代二维 HgBr 中的 Br，可以在价带边缘附近产生浅受主态，并可能导致这些二维二溴化物中的稳定铁磁有序。
