Ultrawide Bandgap Gallium Oxide: Fundamental Understanding From Materials Synthesis to Devices

超宽禁带氧化镓：从材料合成到器件的基本理解

• 批准号: 1708593
• 负责人: Hongping Zhao
• 金额: $ 42万
• 依托单位: Case Western Reserve University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-07-01 至 2017-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1708593&HistoricalAwards=false
• 关键词: Ultrawide; Bandgap; Gallium; Oxide; Fundamental

Nontechnical description: Gallium oxide is a promising material for high-voltage, high-temperature, and high-frequency components in radar and communication systems, wind turbines, and rail traction. Its band gap of ~4.9 electron volts and estimated high breakdown voltage significantly goes beyond currently developed materials, such as GaN and 4H-SiC, while still presenting semiconductor properties. This research focuses on the theoretical modeling of gallium oxide for predicting its fundamental material properties, and the experimental synthesis of this material by using high purity metallic gallium and oxygen as sources. The project aims to produce high quality gallium oxide and to advance the fundamental understanding of this emerging material. Theoretical studies of the fundamental properties of imperfections in the material provides guidance for experimental material growth and material characterization. The development of strategies for synthesis of this material and progress in understanding their properties contribute an important body of work to the research infrastructure. A successful execution of this research is expected to provide a knowledge foundation to power electronics industry with positive impacts on the US economy. This project trains two graduate students in the areas of advanced semiconductor materials synthesis, material characterization, first-principles modeling and device technologies. The research is integrated with educational activities and outreach to benefit the broader community. Technical description: The key research goal is to identify and address the fundamental material challenges of synthesizing high quality ultra-wide-band-gap (UWBG) gallium oxide to advance the next generation high power electronics and short wavelength optoelectronics. The synthesis and fundamental understanding of gallium oxide is still very much in its infancy. The exploration of native defects such as vacancies, interstitials, antisites, and impurities or intentional dopants is expected to be complex because three different oxygen sites and two different gallium sites need to be considered. The research team investigates these problems by combining first-principles modeling with a proposed novel synthesis method for achieving high quality epitaxial gallium oxide films. Specifically, the research efforts include: (i) a low pressure chemical vapor deposition approach to grow gallium oxide; (ii) reduce defects and improve material quality by growing gallium oxide on off-axis substrates; (iii) calculations of the energy of formation and defect levels for point defects, candidate dopants and defect complexes and their experimental signatures, such as electron paramagnetic hyperfine and g-tensors and optical properties; (iv) investigate the crystal defects on electrical properties of gallium oxide. This project provides fundamental understanding of electronic structure, phonons, transport, defects and growth optimization. The theoretical studies will assist in identifying the chemical nature of specific defect levels and thereby will provide guidance for experimental material synthesis and material characterization. The results from this project will fill the knowledge gap in this field, and build a foundation for future applications of this material system.

非技术描述：氧化镓是一种很有前途的材料，用于雷达和通信系统、风力涡轮机和铁路牵引中的高压、高温和高频组件。其约4.9电子伏特的带隙和估计的高击穿电压大大超过了目前开发的材料，如GaN和4H-SiC，同时仍然具有半导体特性。本研究的重点是对氧化镓进行理论建模，预测其基本材料性质，并以高纯金属镓和氧为源进行氧化镓材料的实验合成。该项目旨在生产高质量的氧化镓，并推进对这种新兴材料的基本理解。对材料缺陷基本性质的理论研究为实验材料生长和材料表征提供了指导。这种材料的合成策略的发展和对其性质的理解的进展为研究基础设施贡献了重要的工作。本研究的成功实施有望为电力电子行业提供知识基础，并对美国经济产生积极影响。该项目在先进半导体材料合成、材料表征、第一性原理建模和器件技术领域培养两名研究生。这项研究与教育活动和外展活动相结合，以使更广泛的社区受益。技术描述：主要研究目标是确定和解决合成高质量超宽带隙（UWBG）氧化镓的基本材料挑战，以推进下一代高功率电子和短波光电子技术。对氧化镓的合成和基本认识仍处于起步阶段。由于需要考虑三个不同的氧位和两个不同的镓位，因此对空位、间隙、反位、杂质或故意掺杂等天然缺陷的探索预计将是复杂的。研究小组通过将第一性原理建模与提出的新型合成方法相结合来研究这些问题，以获得高质量的外延氧化镓薄膜。具体来说，研究工作包括：(i)低压化学气相沉积方法来生长氧化镓；（ii）通过在离轴衬底上生长氧化镓来减少缺陷和提高材料质量；（iii）计算点缺陷、候选掺杂剂和缺陷复合物的形成能和缺陷能级及其实验特征，如电子顺磁超精细和g张量以及光学性质；（四）研究氧化镓晶体缺陷对电学性能的影响。该项目提供了对电子结构、声子、输运、缺陷和生长优化的基本理解。理论研究将有助于确定特定缺陷水平的化学性质，从而为实验材料合成和材料表征提供指导。本项目的成果将填补该领域的知识空白，并为该材料系统的未来应用奠定基础。

项目成果

Computational identification of Ga-vacancy related electron paramagnetic resonance centers in β -Ga 2 O 3

β-Ga 2 O 3 中 Ga 空位相关电子顺磁共振中心的计算识别

• DOI: 10.1063/1.5092626
• 发表时间: 2019
• 期刊: Journal of Applied Physics
• 影响因子: 3.2
• 作者: Skachkov, Dmitry;Lambrecht, Walter R. L.;von Bardeleben, Hans Jürgen;Gerstmann, Uwe;Ho, Quoc Duy;Deák, Peter
• 通讯作者: Deák, Peter

Computational study of electron paramagnetic resonance parameters for Mg and Zn impurities in β -Ga 2 O 3

β-Ga 2 O 3 中Mg和Zn杂质的电子顺磁共振参数的计算研究

• DOI: 10.1063/1.5099396
• 发表时间: 2019
• 期刊: Applied Physics Letters
• 影响因子: 4
• 作者: Skachkov, Dmitry;Lambrecht, Walter R.
• 通讯作者: Lambrecht, Walter R.

Computational study of electron paramagnetic resonance spectra for Li and Ga vacancies in LiGaO 2

LiGaO 2 中Li和Ga空位的电子顺磁共振谱计算研究

• DOI: 10.1088/1361-6463/ab6f1c
• 发表时间: 2020
• 期刊: Journal of Physics D: Applied Physics
• 作者: Skachkov, Dmitry;Lambrecht, Walter R;Dabsamut, Klichchupong;Boonchun, Adisak
• 通讯作者: Boonchun, Adisak

Quasiparticle Self‐Consistent GW Study of (Ga 1−x Al x ) 2 O 3 Alloys in Monoclinic and Corundum Structures

单斜晶和刚玉结构 (Ga 1−x Al x ) 2 O 3 合金的准粒子自一致晶粒尺寸研究

• DOI: 10.1002/pssb.201900317
• 发表时间: 2019
• 期刊: physica status solidi (b
• 作者: Ratnaparkhe, Amol;Lambrecht, Walter R.
• 通讯作者: Lambrecht, Walter R.