Identification of point defects in GaN materials and their impact on device performance

GaN 材料中点缺陷的识别及其对器件性能的影响

• 批准号: 2734689
• 金额: --
• 依托单位: University of Manchester
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2734689
• 关键词: Identification; point; defects; GaN; materials

The project proposes to extend the electrical characterisation techniques used for smaller gap materials by the Manchester group for decades to measure the electrical properties of defects in wide band gap semiconductors. The most important wide gap materials at the present time are GaN and InGaN. They are used to make low energy LED lighting and highpower transistors. Today's generation of these devices does not function as well as would seem possible from the properties of the materials and at the present time functionality and performance is limited. This is due, at least in part, to the presence of point defects in the component materials and devices. Eg, In LEDs so called Shockley-Reed-Hall recombination due to gap states is still a significant efficiency loss mechanism. The student will use deep level transient spectroscopy and photoluminescence techniques to identify the nature of the point defects in these materials and how they impact on real LED and transistor devices. Particular defects and impurities will be introduced, either by the industrial collaborator during growth or by using eg implantation or irradiation. The resulting defect energy levels will be then characterised using the techniques described, and the impact of device performance assessed. The nitride materials are still their infancy as semiconductors, they contain high levels of point defects, vacancies, interstitials and impurities such as carbon. The electronic behaviour of these defects is almost completely unknown. What is known is that real world devices show undesirable properties such as current collapse in transistors and anomalous efficiency droop in LEDs. These effects are believed to be due to defect states, but as of today there is no definitive demonstration of what defect is responsible. This project represents a tremendous opportunity to perform world class, high impact, research in this area.

该项目建议将曼彻斯特小组数十年来用于较小间隙材料的电气特性技术扩展到测量宽带隙半导体中缺陷的电气特性。目前最重要的宽禁带材料是GaN和InGaN。它们被用来制造低能量的LED照明和高功率晶体管。今天这一代的这些设备的功能并不像从材料的性质看起来可能的那样好，并且目前功能和性能是有限的。这至少部分是由于在组件材料和器件中存在点缺陷。例如，在LED中，由于间隙状态而引起的所谓的Shockley-Reed-Hall复合仍然是显著的效率损失机制。学生将使用深能级瞬态光谱和光致发光技术来识别这些材料中的点缺陷的性质，以及它们如何影响真实的LED和晶体管器件。工业合作者在生长过程中或通过使用植入或辐照等方式，会引入特定的缺陷和杂质。然后，将使用所描述的技术来表征所产生的缺陷能级，并评估器件性能的影响。氮化物材料作为半导体仍处于起步阶段，它们含有高水平的点缺陷、空位、杂质和杂质如碳。这些缺陷的电子行为几乎是完全未知的。已知的是，真实的世界器件显示出不期望的特性，诸如晶体管中的电流崩溃和LED中的异常效率下降。这些影响被认为是由于缺陷状态，但到今天为止，还没有明确的证据表明是什么缺陷造成的。这个项目代表了一个巨大的机会，在这个领域进行世界级的，高影响力的研究。