Atomically Precise Delineation of As Antisite Defect States from Undoped Gallium Arsenide Host Lattice by Scanning Tunneling Microscopy and Spectroscopy Measurements and Density Functional Theory Calculations
Atomically Precise Delineation of As Antisite Defect States from Undoped Gallium Arsenide Host Lattice by Scanning Tunneling Microscopy and Spectroscopy Measurements and Density Functional Theory Calculations
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通过扫描隧道显微镜和光谱测量以及密度泛函理论计算对未掺杂砷化镓主晶格的 As 反位缺陷态进行原子精确描绘
DOI：
10.1002/pssb.202100652
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发表时间：
2022
期刊：
影响因子：
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通讯作者：
Kim Yousoo
中科院分区：
文献类型：
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作者：
Balgos Maria Herminia M.;Esca?o Mary Clare S.;Jaculbia Rafael B.;Quang Nguyen Tien;Prieto Elizabeth Ann P.;Estacio Elmer S.;Salvador Arnel A.;Somintac Armando S.;Tani Masahiko;Hayazawa Norihiko;Kim Yousoo
利用扫描隧道显微镜(STM)、光谱和密度泛函理论计算相结合的方法，以原子精度准确地描述了砷反位缺陷(ASGA)亚表面和周围As原子的电子性质。在AsGalocate在第二层(2-AsGA)的GaAs110表面上，发现由2-AsGamanififate引起的能隙中态在AsGA键位形成鲜明的对比。此外，研究还表明，在大的负偏压下拍摄的STM图像主要受邻近表面原子的局域态密度的影响。这些态导致在2-AsGa缺陷周围的填充态STM图像中形成四瓣对称对比度。这些结果为原子尺度的表面/亚表面缺陷工程提供了新的见解。
Using a combination of scanning tunneling microscopy (STM) and spectroscopy with density functional theory calculations, the electronic properties of the subsurface arsenic antisite defect (AsGa) are unambiguously delineated from those of the surrounding As atoms in undoped gallium arsenide (GaAs) lattice with atomic precision. In the GaAs(110) surface with AsGalocated at the second layer (2‐AsGa), it is found that the midgap state induced by 2‐AsGamanifests as a bright contrast at the AsGaAs bond site. Furthermore, it is shown that STM images taken at large magnitudes of negative sample bias are dominated by the local density of states of neighboring surface As atoms. These states lead to a four‐lobe symmetric contrast in the filled‐state STM image around the 2‐AsGadefect. These results provide insights for surface/subsurface defect engineering at the atomic scale.