Self-Diffusion in beta-Ga2O3 Single Crystals

β-Ga2O3 单晶中的自扩散

• 批准号: 433461542
• 负责人: Professor Dr. Harald Schmidt
• 金额: --
• 依托单位: Institut für Metallurgie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2019
• 资助国家: 德国
• 起止时间: 2018-12-31 至 2023-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/433461542?language=en
• 关键词: Self; Diffusion; beta; Ga2O3; Single

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.

氧化镓（β-Ga2O3）是一种超宽带隙半导体，由于其在多种应用（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，在各个技术领域中的重要性日益增加。 β-Ga2O3 的电学和光学性质主要取决于本征点缺陷（氧空位、镓填隙、镓空位等）的浓度、电荷状态和迁移。自扩散实验可以提供有关材料中固有缺陷的性质及其迁移性的信息。然而，到目前为止，文献中还没有自扩散研究。本提案的目的是系统地实验测定 β-Ga2O3 单晶中氧和镓示踪剂扩散率随温度的变化。这项工作将通过二次离子质谱（SIMS）进行。氧示踪剂扩散实验将通过使用 18O2 作为气态示踪剂源的同位素交换来实现。为了研究Ga扩散，将使用Al作为替代示踪剂。根据结果​​，将得出活化能和指前因子。扩散实验将根据不同温度下的氧分压进行。通过考虑基本缺陷反应并与文献中给出的理论工作进行比较，可以证明或放弃关于主要缺陷结构及其动力学的某些模型假设。这些结果还将有助于了解电子电导率对氧分压的依赖性以及在 900 K 以下的中等温度下离子电导率的贡献。