Self-Diffusion in beta-Ga2O3 Single Crystals

氧化镓（β-Ga 2 O3）是一种超宽带隙半导体，由于其在各种应用（电力电子、气体传感器、光电探测器、透明导电氧化物等）中的多功能用途，在各种技术领域中的重要性日益增加。β-Ga_2 O_3的电学和光学性质主要取决于本征点缺陷（氧空位、镓空位、镓空位等）的浓度、电荷状态和迁移。自扩散实验可以提供关于材料中的本征缺陷的性质及其迁移率的信息。然而，到目前为止，有没有自扩散的研究可在literation.The本建议的目的是系统的实验测定的氧和镓示踪剂在β-Ga 2 O 3单晶的扩散率作为温度的函数。这项工作将与二次离子质谱（西姆斯）进行。氧示踪剂扩散实验将通过使用18 O2作为气态示踪剂源的同位素交换来实现。为了研究Ga的扩散，Al将被用作替代示踪剂。从结果中，活化能和指前因子将被导出。扩散实验将在不同温度下作为氧分压的函数进行。通过考虑基本的缺陷反应和比较，在文献中给出的理论工作，某些模型假设的主要缺陷结构和它们的动力学可以被证明或丢弃。这些结果也将有助于理解在低于900 K的中等温度下电子电导率与氧分压的关系以及离子电导率的贡献。

Gallium oxide (beta-Ga2O3) is an ultra-wide bandgap semiconductor with increasing importance in various technological fields because of its multifunctional use in diverse applications (power electronics, gas sensor, photo detector, transparent conducting oxide etc.). The electrical and optical properties of beta-Ga2O3 depend critically on the concentration, charge state and migration of native point defects (oxygen vacancies, gallium interstitials, gallium vacancies etc.). Self-diffusion experiments can give information on the nature of native defects and their mobility in the material. However, up to now there are no self-diffusion studies available in literature.The aim of the present proposal is the systematic experimental determination of oxygen and gallium tracer diffusivities in beta-Ga2O3 single crystals as a function of temperature. This work will be carried out with secondary ion mass spectrometry (SIMS). Oxygen tracer diffusion experiments will be achieved by isotope exchange using 18O2 as a gaseous tracer source. In order to investigate the Ga diffusion, Al will be used as a substitute tracer. From the results, activation energies and pre-exponential factors will be derived. The diffusion experiments will be done as a function of oxygen partial pressure at different temperatures. By consideration of fundamental defect reactions and comparison to theoretical work as given in literature, certain model assumptions on dominating defect structures and their kinetics can be proven or discarded. The results will also help to understand the oxygen partial pressure dependence of electronic conductivity and the contribution of ion conductivity at moderate temperatures below 900 K.