Spin-related electronic structure plays an important role in designing new-type spintronic devices. Herein, we unravel the ferromagnetic and optical behaviors of double-faced FeReS₃ with asymmetric defects based on the density functional theory. Different from conventional two-dimensional materials, the spontaneous spin polarization strongly relates with the spatial distribution of anion defects. The superficial and intrastratal S defects make the occupation of Fe-3d orbital unfilled, leading to a distinguishable spin polarization. Our results indicate that structural deformation can regulate the strong exchange interactions between spin sites for achieving room temperature ferromagnetism; interestingly, the S defects at opposite surface cannot give rise to this behavior. We propose to identify the types of S defects in double-faced FeReS₃ by comparing their absorption fingerprints.

自旋相关的电子结构在设计新型自旋电子器件中起着重要作用。在这里，我们解开了双面 FeReS ₃的铁磁和光学行为基于密度泛函理论的不对称缺陷。与传统二维材料不同，自旋极化与阴离子缺陷的空间分布密切相关。表面和层内 S 缺陷使 Fe-3d 轨道的占据未填充，导致可区分的自旋极化。我们的结果表明，结构变形可以调节自旋位点之间的强交换相互作用，以实现室温铁磁性；有趣的是，相反表面的 S 缺陷不会引起这种行为。我们建议通过比较它们的吸收指纹来识别双面 FeReS ₃中 S 缺陷的类型。