基于第一性原理的二维g-AlN材料p型掺杂研究

半导体材料通过掺杂实现n型和p型载流子导电在半导体器件领域具有重要意义,理论上可通过计算电荷转移能级和缺陷形成能来探索半导体材料的n型和p型掺杂效率。基于第一性原理,结合二维带电缺陷计算方法,类石墨烯氮化铝(graphene-like AlN, g-AlN)中的四种(Be_Al,Mg_Al,Ca_Al,Sr_Al)潜在p型掺杂缺陷的结构、磁学、电学和缺陷形成能及转移能级被系统地计算。结果表明,所有缺陷体系均表现为深受主能级特性,很难为二维g-AlN提供p型载流子,它们反而会捕获g-AlN中的空穴,从而严重影响二维g-AlN材料的空穴导电率。Be_Al在整个电子化学势范围内具有最小的形成能,因此更加容易掺入到g-AlN中,影响g-AlN材料的p型掺杂效率。

Study on p-Type Doping of Two-Dimensional g-AlN Materials Based on First-Principles

The realization of n-type and p-type carrier conductivity by doping in semiconductor materials is of great significance in the field of semiconductor devices. Theoretically, the n-type and p-type doping efficiency of semiconductor materials can be explored by calculating charge transfer energy levels and defect formation energy. The structural, magnetic, electronic, defect formation energy and charge transfer energy levels of four potential p-type doped defects in g-AlN (Be_Al, Mg_Al, Ca_Al, Sr_Al) were systematically calculated based on frist-principles and combined with two-dimensional (2D) charged defect calculation method.The results show that all defective systems are deep acceptor energy levels, and it is difficult to provide p-type carriers for the 2D AlN. On the contrary, they will capture the holes in AlN, which will seriously affect the hole conductivity of 2D g-AlN materials. Be_Al has the minimum forming energy in the whole range of electronic chemical potential, so it is easier to be doped into g-AlN, affecting the p-type doping efficiency of g-AlN materials.