Obtaining a reliable positive-type (p-type) GaN semiconductor is difficult because of the unipolarity of GaN. This difficulty is one of the bottlenecks restricting the development of GaN-based optoelectronic devices. To address this problem, this paper adopted the method of generalized gradient approximation (GGA) plane wave ultrasoft pseudopotential based on the framework of density functional theory to construct Ga₃₅MN₃₆, Ga₃₄MN₃₆, and Ga₃₄MH_iN₃₆ (M = Be/Mg/Ca; H_i = interstitial hydrogen) models. Ga₃₅MN₃₅ and Ga₃₅MH_iN₃₅ (M = Be/Mg/Ca) models were also constructed. Results of our calculations indicated that the Ga₃₅MN₃₅ and Ga₃₅MH_iN₃₅ (M = Be/Mg/Ca) models cannot achieve a p-type doping system. Furthermore, the formation energy of Ga₃₄MN₃₆ and Ga₃₄MH_iN₃₆ (M = Be/Mg/Ca) systems was greater under Ga-rich conditions than that under N-rich conditions, indicating that both doping systems more readily formed and had a more stable structure under N-rich conditions. Moreover, the formation energy of Ga₃₄MH_iN₃₆ (M = Be/Mg/Ca) system was lower than that of Ga₃₄MN₃₆ (M = Be/Mg/Ca) system, and the existence of interstitial H proved to be beneficial to the improvement in system stability. The Ga₃₄CaH_iN₃₆ system had the largest hole mobility and the best conductivity. Therefore, the Ga₃₄CaH_iN₃₆ system is an ideal material for the application of conductive GaN devices. This study provides guidance into the preparation of p-type conductive GaN materials.

中文翻译：

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间隙 H 和点空位对 Be/Mg/Ca 掺杂 GaN p 型导电性能影响的第一性原理研究

由于 GaN 的单极性，因此很难获得可靠的正型（p 型）GaN 半导体。这一难点是制约GaN基光电器件发展的瓶颈之一。针对这一问题，本文基于密度泛函理论的框架，采用广义梯度逼近(GGA)平面波超软赝势的方法构造了Ga ₃₅ MN ₃₆、Ga ₃₄ MN ₃₆和Ga ₃₄ MH _i N ₃₆ (M = Be/Mg/Ca；H _i  = 间隙氢）模型。Ga ₃₅ MN ₃₅和 Ga ₃₅ MH _i N还构建了₃₅ (M = Be/Mg/Ca) 模型。我们的计算结果表明 Ga ₃₅ MN ₃₅和 Ga ₃₅ MH _i N ₃₅ (M = Be/Mg/Ca) 模型无法实现 p 型掺杂系统。此外，Ga ₃₄ MN ₃₆和Ga ₃₄ MH _i N ₃₆ (M = Be/Mg/Ca)体系在富Ga条件下的形成能大于富N条件下的形成能，表明两种掺杂体系更容易形成并且在富氮条件下具有更稳定的结构。此外，Ga ₃₄ MH _i N ₃₆的形成能(M = Be/Mg/Ca)体系低于Ga ₃₄ MN ₃₆ (M = Be/Mg/Ca)体系，且间隙H的存在被证明有利于提高体系稳定性。Ga ₃₄ CaH _i N ₃₆体系具有最大的空穴迁移率和最好的导电性。因此，Ga ₃₄ CaH _i N ₃₆体系是应用导电GaN器件的理想材料。该研究为 p 型导电 GaN 材料的制备提供了指导。