Zhang Xiaoning, Zhang Shenglong, Liang Xi, Yang Jia-Yue, Liu Linhua
Opt Express. 2023 Nov 20;31(24):40765-40780. doi: 10.1364/OE.504719.
β-GaO as an ultra-wide bandgap material is widely used in space missions and nuclear reactor environments. It is well established that the physical properties of β-GaO would be affected by radiation damage and temperature in such application scenarios. Defects are inevitably created in β-GaO upon irradiation and their dynamic evolution is positively correlated with the thermal motion of atoms as temperature increases. This work utilizes first-principles calculations to investigate how temperature influences the electronic and optical properties of β-GaO after radiation damage. It finds that the effect of p-type defects caused by Ga vacancies on optical absorption diminishes as temperature increases. The high temperature amplifies the effect of oxygen vacancies to β-GaO, however, making n-type defects more pronounced and accompanied by an increase in the absorption peak in the visible band. The self-compensation effect varies when β-GaO contains both Ga vacancies and O vacancies at different temperatures. Moreover, in the case of Ga (O) vacancies, the main characters of p(n)-type defects caused by uncharged Ga (O) vacancies disappear. This work aims to understand the evolution of physical properties of β-GaO under irradiation especially at high temperatures, and help analyze the damage mechanism in β-GaO-based devices.
β-GaO作为一种超宽带隙材料，广泛应用于太空任务和核反应堆环境中。在这种应用场景下，β-GaO的物理性质会受到辐射损伤和温度的影响，这是众所周知的。β-GaO在辐照时不可避免地会产生缺陷，并且随着温度升高，它们的动态演化与原子的热运动呈正相关。这项工作利用第一性原理计算来研究温度如何影响辐射损伤后β-GaO的电子和光学性质。研究发现，随着温度升高，由Ga空位引起的p型缺陷对光吸收的影响会减弱。然而，高温会增强氧空位对β-GaO的影响，使n型缺陷更加明显，并伴随着可见光波段吸收峰的增加。当β-GaO在不同温度下同时含有Ga空位和O空位时，自补偿效应会发生变化。此外，在Ga（O）空位的情况下，由不带电的Ga（O）空位引起的p（n）型缺陷的主要特征消失。这项工作旨在了解β-GaO在辐照下尤其是在高温下的物理性质演变，并有助于分析基于β-GaO的器件中的损伤机制。
