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arXiv · 2512.03390

Origin of shallow n-type doping in AlN and Al-rich AlGaN

Yujie Liu·Sieun Chae·Emmanouil Kioupakis
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Abstract

Achieving efficient n-type doping in AlN, a representative ultrawide bandgap (UWBG) semiconductor, remains a longstanding challenge that limits its application in high-power electronics and deep-ultraviolet optoelectronics. Conventional dopants in AlN often introduce deep levels or form compensating complexes, leading to low free-carrier concentrations. In this work, we combine first-principles defect calculations with a structural search method tailored to explore metastable configurations to systematically investigate donor-type defects in AlN. Our results reveal that the aluminum interstitial ($Al_i$) can exhibit shallow-donor behavior in specific metastable configurations that were previously overlooked. This discovery expands the understanding of n-type dopability in AlN, and highlights the critical role of metastable defects in modulating electronic properties.

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Yujie Liu, Sieun Chae, Emmanouil Kioupakis. 2025-12-03. Origin of shallow n-type doping in AlN and Al-rich AlGaN. https://arxiv.org/abs/2512.03390

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