In this study, the first-principles method is used to study the structural stability and electronic properties of GaAs/Ga_1−xAl_xAs and Al_xGa_1−xAs/Al_yGa_1−yAs superlattice nanowires. Calculations show that GaAs/Ga_1−xAl_xAs superlattice nanowires with smaller Al component spacing have higher structural stability. The increase of Al composition will further weaken the stability of GaAs/Ga_1−xAl_xAs heterostructure nanowires. Compared with the pure GaAs nanowires, the work function of GaAs/Ga_1−xAl_xAs heterostructure nanowires is all reduced, indicating that the variable Al composition heterostructure can enhance the photoemission ability. In addition, heterostructures with different configurations exhibit different electronic properties. Moreover, a powerful built-in electric field is formed across the GaAs/Al_xGa_1−xAs superlattice interface, which will further promote the migration of photoelectrons from low Al composition layer to high Al composition layer. GaAs/Ga_1−xAl_xAs superlattice nanowires are promising to be the high-performance photocathode materials.

在这项研究中，第一原理方法用于研究GaAs / Ga _{1- x} Al _x As和Al _x Ga _{1- x} As / Al _y Ga _{1- y} As超晶格纳米线的结构稳定性和电子性能。计算表明，Al组分间距较小的GaAs / Ga _{1- x} Al _x As超晶格纳米线具有较高的结构稳定性。Al组成的增加将进一步削弱GaAs / Ga _{1- x} Al _x As异质结构纳米线的稳定性。与纯GaAs纳米线相比，GaAs / Ga _{1- x}的功函数Al _x As异质结构纳米线均被还原，表明可变的Al组成异质结构可以增强光发射能力。另外，具有不同构型的异质结构表现出不同的电子性质。此外，在GaAs / Al _x Ga _{1- x} As超晶格界面上形成了强大的内置电场，这将进一步促进光电子从低Al组成层向高Al组成层的迁移。GaAs / Ga _{1- x} Al _x As超晶格纳米线有望成为高性能的光电阴极材料。