The effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN
The effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN
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DOI：
10.1063/1.122579
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发表时间：
1998-11
影响因子：
4
通讯作者：
A. F. Wright;U. Grossner
中科院分区：
文献类型：
--
作者：
A. F. Wright;U. Grossner
密度泛函理论计算研究了掺杂和生长化学计量对 GaN 穿透刃位错核心结构的影响。检查了四种候选结构，发现它们的形成能强烈依赖于费米能级和生长化学计量。位错核心处具有镓空位的结构预计在富氮条件下生长的n型材料中最稳定，而在这些条件下生长的p型材料中没有空位的结构最稳定。在富镓条件下生长的材料中，位错核心处具有氮空位的结构预计在p型材料中最稳定，而多种核心结构应存在于n型材料中。根据生长条件，边缘位错预计将在 n 型材料中充当电子陷阱，并且可能在 p 型材料中充当空穴陷阱。
Density-functional-theory calculations have been performed to study the effect of doping and growth stoichiometry on the core structure of a threading edge dislocation in GaN. Four candidate structures were examined and their formation energies were found to depend strongly on Fermi level and growth stoichiometry. A structure having gallium vacancies at the dislocation core is predicted to be most stable in n-type material grown under nitrogen-rich conditions, while a structure without vacancies is most stable in p-type material grown under these conditions. In material grown under gallium-rich conditions, a structure having nitrogen vacancies at the dislocation core is predicted to be most stable in p-type material, whereas a variety of core structures should be present in n-type material. Edge dislocations are predicted to behave as electron traps in n-type material and may act as hole traps in p-type material depending on the growth conditions.