Characterising the composition, defect concentrations and optical properties of semiconductor alloys based on gallium oxide (Ga2O3)

β相氧化镓（β - ga2o3）在电子和光子器件中的应用引起了人们的极大兴趣，特别是在其超宽带隙（接近5 eV）的电力电子应用中。除了大的带隙外，其可见光的高透射率（~ 90%）使Ga2O3成为UV光电子应用的主要竞争者，如太阳盲光电探测器和闪烁体。将Ga2O3与锡（Sn）、铟（In）或铝（Al）等元素合金化的机会增加了潜力，带来了调整带隙和提高性能的可能性。例如，由氧化锡镓（TGO）制成的光电探测器已被证明在器件对紫外光的响应方面优于Ga2O3器件一个数量级以上。该项目将结合先进的材料分析技术来表征Ga2O3和相关合金。电子探针将用于测量成分，使用波长色散x射线分析，光学发射，使用阴极发光，具有高空间分辨率（低至约100纳米）。对于更多的绝缘样品，将使用环境扫描电子显微镜与能量色散x射线分析一起测量CL。将空间分辨光学数据与来自同一区域的成分信息相关联，将有助于了解各种Ga2O3合金体系的性能以及缺陷对材料性能的影响。在各种气氛下退火前后测量样品将用于确定存在哪些缺陷以及如何控制它们的浓度。

Beta-phase gallium oxide (beta-Ga2O3) is attracting significant interest for use in electronic and photonic devices, particularly for applications in power electronics where its ultra-wide bandgap (approaching 5 eV) is advantageous. As well as the large bandgap, its high transmission of visible light (~ 90%) makes Ga2O3 a leading contender for UV optoelectronics applications such as solar-blind photodetectors and scintillators. The chance to alloy Ga2O3 with elements such as tin (Sn), indium (In) or aluminium (Al) adds to the potential, bringing in possibilities to tune the bandgap and enhance performance. For example, photodetectors made from tin gallium oxide (TGO) have been shown to outperform Ga2O3 devices by more than one order of magnitude in device response to UV light.The project will characterise Ga2O3 and related alloys using a combination of advanced materials analysis techniques. An electron microprobe will be used to measure composition, using wavelength dispersive X-ray analysis, and optical emission, using cathodoluminescence, with high spatial resolution (down to approximately 100 nm). For more insulating samples an environmental scanning electron microscope will be used to measure the CL alongside energy dispersive X-ray analysis. Correlating the spatially resolved optical data with the compositional information from the same area will provide an understanding of the properties of the various Ga2O3 alloy systems as well as information on the impact of defects on the material performance. Measuring samples before and after annealing in various atmospheres will be used to identify which defects are present and how their concentrations can be controlled.