Abstract Chromium triiodide (CrI3) monolayer, as a two-dimensional (2D) intrinsic ferromagnetic (FM) semiconductor, creates a large number of opportunities for the spintronic application of atomically thin magnets. Using density functional theory, we studied the electronic structures and carrier doping of CrI3 monolayer with vacancy defects. The energy band structures show that the flat-bands near the Fermi level in the spin-up conduction bands split into isolated flat-bands for the CrI3 monolayer with I vacancies, regardless of the vacancy concentration, whereas these flat-bands cross together in the perfect case. Further analysis suggests that the separation of the flat-bands results from the reduction of the Cr–I interaction induced by I vacancies. The introduction of I vacancies not only preserves the semiconducting feature, but also enhances the total magnetic moments of I-vacancy-contained CrI3, and the enhancement of magnetic moments is closely related with the number of vacancies. With the help of the flat-band splitting, the carrier doping could be used to further tune the magnetic moments, and simultaneously maintain the semiconducting characteristic in the I-vacancy-contained CrI3. Thus, our findings extend the realistic application of CrI3 monolayer in spintronics.

中文翻译：

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缺陷 CrI3 单层中的平带分裂感应可调磁性

摘要 三碘化铬 (CrI3) 单层作为二维 (2D) 本征铁磁 (FM) 半导体，为原子级薄磁体的自旋电子应用创造了大量机会。使用密度泛函理论，我们研究了具有空位缺陷的 CrI3 单层的电子结构和载流子掺杂。能带结构表明，无论空位浓度如何，自旋向上导带中费米能级附近的平带分裂为具有 I 空位的 CrI3 单层的孤立平带，而这些平带在完美的案例。进一步的分析表明，平带的分离是由于 I 空位引起的 Cr-I 相互作用的减少。I 空位的引入不仅保留了半导体特性，但也增强了含I空位的CrI3的总磁矩，磁矩的增强与空位数量密切相关。在平带分裂的帮助下，载流子掺杂可用于进一步调整磁矩，同时保持含 I 空位的 CrI3 的半导体特性。因此，我们的研究结果扩展了 CrI3 单层在自旋电子学中的实际应用。