等离子体处理实现β-Ga2O3表面氧空位缺陷与非晶化调控及其对深紫外光探测特性的影响

β-Ga2O3因直接超宽带隙（4.9 eV）及稳定的热力学和化学性质特别适于日盲紫外光电器件开发。氧化物中常见的O空位（Vo）缺陷可提供本征载流子而利于提高光增益，也作为陷阱延缓光生载流子复合而限制器件响应速度。本项目提出采用O和Ar等离子体与Ga2O3表面相互作用，一方面精确调控Vo浓度，实现低本征暗电流与高光增益的合理平衡，一方面通过非晶化引入复合中心来提高器件响应速度。项目拟采用PLD生长含有特定浓度Vo缺陷和高质量外延β-Ga2O3薄膜，分别通过改变O和Ar等离子体处理工艺参数来精细调控薄膜中Vo浓度和非晶层厚度；通过表面表征和光电响应测量结合第一性原理模拟计算，建立Vo浓度和非晶层厚度与薄膜光生载流子寿命及输运特性间的关联，揭示其影响规律与微观机制。本项目可为β-Ga2O3材料及深紫外光探测器研究提供理论依据和技术基础，也对一般氧化物半导体Vo调控研究及器件开发具有普适指导意义。

β-Ga2O3 is particularly suitable for the development of solar-blind UV optoelectronic devices due to its direct wide bandgap (4.9 eV) and stable thermodynamic and chemical properties. The O-vacancy (Vo) defects commonly existed in oxides can provide the intrinsic carriers and help to increase the light-gain, and on the other hand can delay the recombination of photo-generated carriers as traps and limit the response speed of the device. This project proposes to use the interaction between O and Ar plasma and the Ga2O3 surface, on the one hand, to accurately regulate the Vo concentration to achieve a reasonable balance between the low intrinsic dark-current and high light-gain, on the other hand, to improve the response speed of the device through the introduction of amorphous (disordered) phase as recombination centers. The project is intended to use PLD to grow β-Ga2O3 films with a specific concentration of Vo defects and with high epitaxial quality, respectively, and well control the Vo concentration and amorphous-layer thickness in the films by changing the processing parameters of O and Ar plasma treatment. Through surface characterizations and photoelectric response measurements combined with the first-principles calculations modeling, the correlation between the Vo concentration/ amorphous-layer thickness and the carriers life/ transport characteristics of the film is established, and their influence law and microscopic mechanism are revealed. This project can provide theoretical guide and technical basis for the studies of β-Ga2O3 materials and deep-ultraviolet detecting devices, and can also offer general guide for the research of Vo regulation and device development for other oxides semiconductors.