Ab initio calculation of the stoichiometry and structure of the (0001) surfaces of GaN and AlN
Ab initio calculation of the stoichiometry and structure of the (0001) surfaces of GaN and AlN
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DOI：
10.1103/physrevb.57.15360
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发表时间：
1998-06-15
影响因子：
3.7
通讯作者：
Page, JB
中科院分区：
文献类型：
--
作者：
Fritsch, J;Sankey, OF;Page, JB
我们使用基于局域密度近似和赝势法的从头算局域计算，研究了纤锌矿相 GaN 和 AIN 的阴离子和阳离子封端 (0001) 表面的化学计量以及原子和电子结构。研究的所有稳定表面构型在原子组成和周期性方面与理想的块状终端不同。我们比较了 GaN 和 AW(0001) 的各种 p(2X2) 几何形状计算的总能量。空位结构被发现是阴离子和阳离子封端表面最稳定的构型。对于富含金属的生长条件，bur 计算有利于金属原子在阳离子封端表面上的吸附。由于空位的形成或 III 族原子的吸附，阴离子和阳离子衍生的悬挂键态出现在体带隙中。发现两种类型的平坦表面均通过 3/4 ML 的氢吸附而稳定。
We have investigated the stoichiometry and the atomic and electronic structure of the anion-and cation-terminated (0001) surfaces of wurtzite-phase GaN and AIN, using ab initio local-orbital calculations based on the local-density approximation and the pseudopotential method. All stable surface configurations studied differ in atomic composition and periodicity from the ideal bulklike termination. We compare the total energy computed for various p(2X2) geometries of GaN and AW(0001). Vacancy structures are found to be the most stable configurations for the anion-and cation-terminated surfaces. For metal-rich growth conditions, bur calculations favor the adsorption of metal atoms on the cation-terminated surface. Anion-and cation-derived dangling-bond states appear in the bulk band gap as a result of the formation of vacancies or the adsorption of group-Ill atoms. Flat surfaces of both types are found to be stabilized by a 3/4 ML adsorption of hydrogen.