Theoretical Investigations for Surface Reconstructions of Submonolayer InAs Grown on GaAs(001)
Theoretical Investigations for Surface Reconstructions of Submonolayer InAs Grown on GaAs(001)
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GaAs(001)上生长的亚单层InAs表面重构的理论研究
DOI：
10.1002/pssa.201800476
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Pradipto Abdul-Muizz
中科院分区：
文献类型：
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作者：
Ito Tomonori;Akiyama Toru;Nakamura Kohji;Pradipto Abdul-Muizz
用赝势从头计算方法研究了GaAs（001）衬底上生长的亚单层InAs的表面重构.随着As化学势的降低，计算的形成能作为As化学势的函数显示，在InAs覆盖度θ= 0.71单层（ML）时，表面重构从（4 × 3）（具有一个In-As和两个As二聚体）变为（2 × 4）（θ= 1.38 ML），通过c（4 × 4）（具有两个In-As和一个As二聚体）（θ= 0.88 ML）。应该注意的是，具有两个In-As和一个As二聚体的（4 × 3）比具有相同二聚体成分的c（4 × 4）稳定性较差。具有两个In-As和一个As二聚体的c（4 × 4）仍然是稳定的，即使由于GaAs的晶格约束倾向于使c（4 × 4）和（2 × 4）不稳定，但稳定许多（4 × 3）相。因此，新发现的c（4 × 4）相是在InAs/GaAs（001）（4 × 3）面上形成（2 × 4）畴的中间相。
Surface reconstructions of submonolayer InAs grown on GaAs(001) are investigated using ab initio pseudopotential calculations. Decreasing As chemical potential, calculated formation energies as a function of As chemical potential reveals that the surface reconstructions change from (4 × 3) with one In‐As and two As dimers at InAs coverageθ= 0.71 monolayer (ML) to (2 × 4) atθ= 1.38 ML via c(4 × 4) with two In‐As and one As dimers atθ= 0.88 ML. It should be noted that the (4 × 3) with two In‐As and one As dimers is less stable than the c(4 × 4) with the same dimer constituents. The c(4 × 4) with two In‐As and one As dimers is still stable even due to the lattice constraint of GaAs that tend to destabilize c(4 × 4) and (2 × 4) but stabilize many (4 × 3) phases. Consequently, the newly found c(4 × 4) is an intermediate phase to form the (2 × 4) domain on the (4 × 3) surface in InAs/GaAs(001).