He Huan, Liu Wenbo, Zhang Pengbo, Liao Wenlong, Tong Dayin, Yang Lin, He Chaohui, Zang Hang, Zong Hongxiang
School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
School of Physics, Dalian Maritime University, Dalian 116026, China.
Materials (Basel). 2020 Aug 17;13(16):3627. doi: 10.3390/ma13163627.
Understanding the properties of defects is crucial to design higher performance semiconductor materials because they influence the electronic and optical properties significantly. Using ab initio calculations, the dynamics properties of nitrogen interstitial in GaN material, including the configuration, migration, and interaction with vacancy were systematically investigated in the present work. By introducing different sites of foreign nitrogen atom, the most stable configuration of nitrogen interstitial was calculated to show a threefold symmetry in each layer and different charge states were characterized, respectively. In the researches of migration, two migration paths, in-plane and out-of-plane, were considered. With regards to the in-plane migration, an intermediated rotation process was observed first time. Due to this rotation behavior, two different barriers were demonstrated to reveal that the migration is an anisotropic behavior. Additionally, charged nitrogen Frenkel pair was found to be a relatively stable defect complex and its well separation distance was about 3.9 Å. Part of our results are in good agreement with the experimental results, and our work provides underlying insights of the identification and dynamics of nitrogen interstitial in GaN material. This study of defects in GaN material is useful to establish a more complete theory and improve the performance of GaN-based devices.
了解缺陷的性质对于设计高性能半导体材料至关重要，因为它们会显著影响材料的电学和光学性质。在本工作中，利用从头算计算系统地研究了GaN材料中氮间隙原子的动力学性质，包括其构型、迁移以及与空位的相互作用。通过引入不同位置的外来氮原子，计算出氮间隙原子最稳定的构型在每层中呈现三重对称性，并分别表征了不同的电荷态。在迁移研究中，考虑了面内和面外两种迁移路径。对于面内迁移，首次观察到一个中间旋转过程。由于这种旋转行为，证明了存在两个不同的势垒，表明迁移是一种各向异性行为。此外，发现带电氮弗伦克尔对是一种相对稳定的缺陷复合体，其良好的分离距离约为3.9 Å。我们的部分结果与实验结果吻合良好，我们的工作为GaN材料中氮间隙原子的识别和动力学提供了潜在的见解。对GaN材料中缺陷的这项研究有助于建立更完整的理论并提高基于GaN的器件的性能。
