Hole localization is a root cause of difficulties in p-type doping of aluminum nitride. Herein, the stability of localized holes in AlN and their susceptibility to self-trapping within bulk material or in the presence of isovalent elements and acceptor impurities are calculated. It is found that self-trapped holes are metastable in bulk AlN, and also exhibit a very low barrier to detrapping. However, holes become trapped in the presence of acceptor impurities as well as isovalent elements such as B, In, and Sc, and may contribute to the broad luminescence observed in AlN alloys. It is also found that hole trapping contributes to the large ionization energies for acceptors in AlN. Most acceptors can also trap a second hole, becoming positively charged and further exacerbating difficulties in doping aluminum nitride p type. The stability of trapped holes is found to scale with atomic size mismatch to Al.

中文翻译：

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AlN 中受主杂质和合金元素处的空穴捕获

空穴定位是氮化铝 p 型掺杂困难的根本原因。在此，计算了 AlN 中局部空穴的稳定性以及它们在大块材料内或在等价元素和受体杂质存在的情况下对自陷的敏感性。发现自陷孔在块状 AlN 中是亚稳态的，并且也表现出非常低的解陷势垒。然而，在受主杂质以及 B、In 和 Sc 等等价元素存在的情况下，空穴会被捕获，并且可能有助于在 AlN 合金中观察到的广泛发光。还发现空穴捕获有助于 AlN 中受体的大电离能。大多数受体还可以捕获第二个空穴，带正电并进一步加剧掺杂氮化铝 p 型的困难。