A comprehensive study of defects in gallium oxide by density functional theory
A comprehensive study of defects in gallium oxide by density functional theory
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DOI：
10.1016/j.commatsci.2022.111950
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发表时间：
2023-02
影响因子：
3.3
通讯作者：
Mohi Uddin Jewel;Samiul Hasan;I. Ahmad
中科院分区：
文献类型：
--
作者：
Mohi Uddin Jewel;Samiul Hasan;I. Ahmad
超宽带隙氧化镓(Ga2O_3)是一种很有前途的电力半导体器件和深紫外光盲光探测器材料。了解Ga2O3点缺陷的性质对于实现性能更好的器件是必要的。基于密度泛函理论，采用广义梯度近似--Perdew-Burke-Ernzerhof交换关联泛函，对刚玉(α)、单斜(β)和正交晶(ε)相中的点缺陷进行了全面的研究。点缺陷包括Ga2O_3各相中的空位、间隙、反位和非本征杂质。列出了富镓(Ga)和富氧(O)生长条件下的缺陷形成能、电荷跃迁能级和缺陷浓度随温度的变化。形成能图表明，Ga2O3相有利于Ga、O空位的形成和非本征杂质的掺入。计算还表明，无论Ga2O3相和生长环境如何，电荷跃迁能级都位于禁带深处。通过探测在金属-有机化学气相沉积(MOCVD)系统中生长的β-Ga2O3薄膜的振动模式，分析了温度对本征点缺陷的影响。
Ultrawide bandgap gallium oxide (Ga2O3) is a promising material for power semiconductor devices and deep ultraviolet (UV) solar-blind photodetectors. Understanding the properties of point defects in Ga2O3is necessary to realize better-performing devices. A comprehensive study based on density functional theory (DFT), using the generalized gradient approximation (GGA): Perdew-Burke-Ernzerhof (PBE) exchange–correlation functional, of point defects in corundum (α), monoclinic (β), and orthorhombic (ε) phases of Ga2O3is presented. The point defects include vacancies, interstitials, antisites, and extrinsic impurities in various phases of Ga2O3. Defect formation energies, charge transition energy levels, and defect concentrations variation with temperature are listed and presented under both gallium-rich (Ga-rich) and oxygen-rich (O-rich) growth conditions. The formation energy diagrams predict that the Ga2O3phases favor the formation of Ga and O vacancies and the incorporation of extrinsic impurities. The calculations also show that the charge transition levels are deep inside the bandgap regardless of the Ga2O3phase and growth environment. The impacts of temperature on the intrinsic point defects are analyzed by probing the vibrational modes of β-Ga2O3thin films grown in a metal–organic chemical vapor deposition (MOCVD) system at 700 °C temperature and annealed at 1100 °C in an O-rich environment.