体相$\eta$(2H)-GaSe的结构与电子性质：含范德华修正的第一性原理DFT计算
Structural and Electronic Properties of Bulk $β$(2H)-GaSe from First-Principles DFT Calculations with van der Waals Corrections
查看机构详情
- Universidad Distrital Francisco José de Caldas（弗朗西斯科·何塞·德卡尔达斯城市大学）
机构由 AI 辅助整理，请以论文原文为准。
浏览论文内容
中文总结 AI 辅助
本文用含DFT-D2范德华修正的DFT计算体相β(2H)-GaSe的结构与电子性质，验证晶格参数与直接带隙，为二维剥离研究提供能量基线。
中文摘要 AI 辅助
硒化镓（GaSe）是一种层状III-VI族半导体，其体相晶体是模拟孤立单层的关键能量参考。我们采用GGA-PBE泛函并辅以半经验Grimme DFT-D2色散修正，对中心对称的$\eta$(2H)-GaSe多型体进行了系统的密度泛函理论（DFT）研究，以准确捕捉弱的范德华层间耦合。优化后的面内晶格参数与实验值吻合良好（误差约1.3%），而面外参数c相对于实验被DFT-D2修正高估，这是该色散方案在成对$C_6$系数未针对所研究化合物类别专门拟合时的一个已知局限。电子结构计算证实了非磁性、直接带隙特征（1.12 eV）。尽管该数值反映了半局域泛函众所周知的带隙低估问题，但定性的能带拓扑准确捕捉了体相材料内部固有的二维载流子限制。因此，这一优化的三维框架为量化剥离过程提供了一致的能量基线，为未来二维极限的理论探索（如用于潜在自旋电子学应用的表面功能化）提供了可靠的起点。
英文摘要
Gallium selenide (GaSe) is a layered III-VI semiconductor whose bulk crystal serves as the essential energetic reference for modeling the isolated monolayer. We present a systematic density-functional-theory (DFT) study of the centrosymmetric $β$(2H)-GaSe polymorph, employing the GGA-PBE functional supplemented with a semiempirical Grimme DFT-D2 dispersion correction to accurately capture the weak van der Waals interlayer coupling. The optimized in-plane lattice parameter agrees well with experimental values (within about 1.3%), while the out-of-plane parameter c is overestimated by the DFT-D2 correction relative to experiment, a known limitation of this dispersion scheme when the pairwise $C_6$ coefficients are not specifically fitted for the compound class under study. Electronic structure calculations confirm a non-magnetic, direct-gap profile (1.12 eV). Although this magnitude reflects the well-known underestimation of semilocal functionals, the qualitative band topology accurately captures the intrinsic two-dimensional carrier confinement within the bulk material. Consequently, this optimized three-dimensional framework provides a consistent energetic baseline for quantifying exfoliation processes, offering a reliable starting point for future theoretical explorations of the two-dimensional limit, such as surface functionalization for potential spintronic applications.
