First-principles studies of beryllium doping of GaN
First-principles studies of beryllium doping of GaN
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DOI：
10.1103/physrevb.63.245205
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发表时间：
2001-06
影响因子：
3.7
通讯作者：
C. Walle;S. Limpijumnong;J. Neugebauer
中科院分区：
文献类型：
--
作者：
C. Walle;S. Limpijumnong;J. Neugebauer
采用基于赝势和密度泛函理论的第一性原理计算方法研究了GaN中铍替代受主和间隙施主的结构和电子性质。在p型GaN中，作为施主的Be化合物的形成能与作为受主的Ga位点上的替代Be的形成能相当。因此，在热力学平衡中，Be杂质的掺入将导致严重的补偿。为了研究Be间隙掺入和外扩散的动力学，我们探索了总能量表面。Be材料的扩散率是高度各向异性的，在垂直于c轴的平面中的迁移势垒为1.2 eV，而沿c轴沿着运动的势垒为2.9 eV。我们还研究了间隙施主和替代受主之间，以及氢和替代铍之间的络合物形成。纤锌矿GaN的结果进行了比较与那些锌-β相。使用Be受体的p型掺杂的后果进行了讨论。
The structural and electronic properties of beryllium substitutional acceptors and interstitial donors in GaN are investigated using first-principles calculations based on pseudopotentials and density-functional theory. In p-type GaN, Be interstitials, which act as donors, have formation energies comparable to that of substitutional Be on the Ga site, which is an acceptor. In thermodynamic equilibrium, incorporation of Be interstitials will therefore result in severe compensation. To investigate the kinetics of Be interstitial incorporation and outdiffusion we have explored the total-energy surface. The diffusivity of Be interstitials is highly anisotropic, with a migration barrier in planes perpendicular to the c axis of 1.2 eV, while the barrier for motion along the c axis is 2.9 eV. We have also studied complex formation between interstitial donors and substitutional acceptors, and between hydrogen and substitutional beryllium. The results for wurtzite GaN are compared with those for the zinc-blende phase. Consequences for p-type doping using Be acceptors are discussed.