Mg Doping Affects Dislocation Core Structures in GaN
Mg Doping Affects Dislocation Core Structures in GaN
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DOI：
10.1103/physrevlett.111.025502
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发表时间：
2013-07-09
影响因子：
8.6
通讯作者：
Moram, M. A.
中科院分区：
文献类型：
--
作者：
Rhode, S. K.;Horton, M. K.;Moram, M. A.
采用像差校正扫描透射电子显微镜研究了高位错密度和低位错密度的未掺杂GaN薄膜以及具有可比性的高位错密度Mg掺杂GaN薄膜中的穿透位错的核心结构。所有样品中的所有a型位错都具有5/7原子核结构。相比之下，大多数（a + c）型位错在未掺杂的GaN解离由于局部应变变化从附近的位错。相反，Mg掺杂防止（a + c）型位错解离。我们的数据表明，Mg对GaN中的位错核心有显著的影响。
Aberration-corrected scanning transmission electron microscopy was used to investigate the core structures of threading dislocations in undoped GaN films with both high and low dislocation densities, and in a comparable high dislocation density Mg-doped GaN film. All a-type dislocations in all samples have a 5/7-atom core structure. In contrast, most (a + c)-type dislocations in undoped GaN dissociate due to local strain variations from nearby dislocations. In contrast, Mg doping prevents (a + c)-type dislocation dissociation. Our data indicate that Mg affects dislocation cores in GaN significantly.