In this study, the oxidation of Ga–polar GaN(0001) surface simulated by using originally developed charge‐transfer‐type interatomic potential is reported on. The adjusted potential parameters reproduce the cohesive energies in the range of 0.3 eV atom−1 and atomic forces with correlation coefficient as high as 0.9, compared to the results of first‐principles calculations for more than 9000 structures associated with oxidation of GaN. The oxidation simulations reveal the formation of a periodic gallium oxide (GaOx) layer grown on GaN(0001) with O atoms replacing N atoms. The atomic distance between Ga–Ga in the GaOx layer along GaN[0001] direction is 3.05 Å, which is longer than wurtzite GaN (2.63 Å) and is quantitatively in agreement with the recent photoelectron holography measurement. The distances of the Ga atoms projected onto the GaN(11–20) plane are determined to be 3.19 Å for the GaOx layer and 2.79 Å for the interfacial GaN. These distances also align quantitatively with the scanning transmission electron microscopy imaging of the native oxide on GaN(0001). Further oxidation simulation in a larger model of 2304 atoms suggests the formation of the layered structure even in the subsequent layers away from the interface of GaN and gallium oxide.

中文翻译：

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电荷转移型分子动力学模拟 GaN(0001) 的表面氧化

在这项研究中，报道了使用最初开发的电荷转移型原子间势模拟Ga极性GaN（0001）表面的氧化。调整后的电势参数再现了 0.3 eV 原子范围内的内聚能−1与9000多个与GaN氧化相关的结构的第一性原理计算结果相比，相关系数高达0.9的原子力。氧化模拟揭示了周期性氧化镓（GaOX) 层生长在 GaN(0001) 上，其中 O 原子取代 N 原子。GaO中Ga-Ga之间的原子距离X沿GaN[0001]方向的层厚度为3.05 Å，比纤锌矿GaN（2.63 Å）长，并且在数量上与最近的光电子全息测量一致。对于 GaO，Ga 原子投影到 GaN(11-20) 平面上的距离确定为 3.19 ÅX层和界面 GaN 为 2.79 Å。这些距离也与 GaN(0001) 上原生氧化物的扫描透射电子显微镜成像定量一致。在 2304 个原子的更大模型中进行的进一步氧化模拟表明，即使在远离 GaN 和氧化镓界面的后续层中也能形成层状结构。