文章基本信息

标题：Reducing Mg Acceptor Activation-Energy in Al_0.83Ga_0.17N Disorder Alloy Substituted by Nanoscale (AlN)₅/(GaN)₁ Superlattice Using Mg_Ga δ-Doping: Mg Local-Structure Effect
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作者：Hong-xia Zhong ; Jun-jie Shi ; Min Zhang 等
期刊名称：Scientific Reports
电子版ISSN：2045-2322
出版年度：2014
卷号：4
DOI：10.1038/srep06710
出版社：Springer Nature
摘要：Improving p -type doping efficiency in Al-rich AlGaN alloys is a worldwide problem for the realization of AlGaN-based deep ultraviolet optoelectronic devices. In order to solve this problem, we calculate Mg acceptor activation energy and investigate its relationship with Mg local structure in nanoscale (AlN)₅/(GaN)₁ superlattice (SL), a substitution for Al_0.83Ga_0.17N disorder alloy, using first-principles calculations. A universal picture to reduce acceptor activation energy in wide-gap semiconductors is given for the first time. By reducing the volume of the acceptor local structure slightly, its activation energy can be decreased remarkably. Our results show that Mg acceptor activation energy can be reduced significantly from 0.44 eV in Al_0.83Ga_0.17N disorder alloy to 0.26 eV, very close to the Mg acceptor activation energy in GaN, and a high hole concentration in the order of 10¹⁹ cm⁻³ can be obtained in (AlN)₅/(GaN)₁ SL by Mg_Ga δ-doping owing to GaN-monolayer modulation. We thus open up a new way to reduce Mg acceptor activation energy and increase hole concentration in Al-rich AlGaN.