Development of High Efficiency Deep Ultraviolet Light Emitting Diodes

题目：高效深紫外发光二极管的发展本研究的目的是开发高效率（20-30%）的深紫外发光二极管。拟议的研究有可能对环境和医疗部门产生重大影响，因为它具体适用于水/空气/食品消毒以及诊断和治疗用途。此外，拟议的研究活动将通过培养各种学科的学生来促进教育，包括半导体薄膜的生长、器件制造和表征以及新兴技术。为了提高项目的有效性和范围，将利用波士顿大学现有的几个渠道，强调本科生和高中实习生的参与，其中许多渠道都非常注重招募代表性不足的少数民族。美国国家科学基金会对这个项目的支持是合理的，因为它是基础科学，它所涉及的技术具有大量的社会和教育效益。具体目标是展示基于生长在p-SiC衬底上的AlGaN合金的高效率（20-30%）深紫外led。该效率值比目前文献报道的最佳结果高3倍。为了实现这一目标，将解决长期存在的低内量子效率（IQE），低注入效率（IE）和低萃取效率（EE）的问题。AlGaN结构将生长在p-SiC衬底上，与常用的蓝宝石衬底相比，它们具有更好的晶格匹配性。通过在生长模式下生长器件的有源区域，从而导致能带结构电位波动，从而实现有效的辐射重组，从而提高IQE。预期IQE值为70%或更高。该LED器件将在退化掺杂的p-SiC衬底上采用倒置结构，再加上极化辅助注入的空穴，预计将导致IE达到50%或更高。在衬底和活性区之间将加入导电的algan基p型DBR，以防止p-SiC衬底的吸收。此外，倒置结构将允许光从设备的透明n-AlGaN侧提取，其可以纹理化以实现最大的光提取，从而实现70%或更高的EE。

Title: Development of High Efficiency Deep Ultraviolet Light Emitting DiodesThe objective of this research is to develop high efficiency (20-30%) deep ultraviolet light emitting diodes. The proposed research has the potential for a strong impact on the environmental and medical sectors, due to specific applications to water / air / food sterilization and for diagnostic and therapeutic uses. Furthermore, the proposed research activities will promote education through the training of students in a variety of disciplines, ranging from growth of semiconductor thin films, device fabrication and characterization, and emerging technologies. To increase the effectiveness and scope of the program, the involvement of undergraduates and high-school interns will be emphasized by taking advantage of several existing channels at Boston University, many of which have a strong focus on the recruitment of underrepresented minorities. The NSF support of this project is justified since it is basic science and the technology it addresses has a large number of societal and educational benefits. The specific goal is to demonstrate high efficiency (20-30%) deep UV LEDs based on AlGaN alloys grown on p-SiC substrates. This efficiency value is 3 times higher than the best result currently reported in the literature. In order to accomplish this goal long standing problems of low internal quantum efficiency (IQE), low injection efficiency (IE), and low extraction efficiency (EE) will be addressed. The AlGaN structures will be grown on p-SiC substrates, to which they are better lattice matched than the commonly used sapphire substrates. Improvements in IQE will be obtained by growing the active region of the device under a growth mode, which leads to band structure potential fluctuations and thus efficient radiative recombination. The expected IQE value will be 70% or higher. The LED device will be an inverted structure on a degenerately doped p-SiC substrate, which together with polarization assisted injection of holes is expected to lead to IE 50% or higher. A conducting AlGaN-based p-type DBR will be incorporated between the substrate and the active region to prevent absorption in the p-SiC substrate. Furthermore, the inverted structure will allow light extraction from the transparent n-AlGaN side of the device, which can textured for maximum light extraction leading to EE of 70% or higher.