Development of High Efficiency Deep Ultraviolet Light Emitting Diodes

职务名称：高效率深紫外发光二极管的研制本研究的目的是研制高效率（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强烈的影响，因为它具体应用于水/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训学生学习各种学科来促进教育，这些学科包括半导体薄膜的生长、器件制造和表征以及新兴技术。为了提高该方案的有效性和范围，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，其中许多渠道非常注重招聘代表性不足的少数民族。美国国家科学基金会对该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在p-SiC衬底上生长的AlGaN合金的高效率（20-30%）深紫外LED。该效率值比目前文献中报道的最佳结果高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）和低提取效率（EE）的问题。AlGaN结构将在p-SiC衬底上生长，与常用的蓝宝石衬底相比，AlGaN结构与p-SiC衬底具有更好的晶格匹配。IQE的改进将通过在生长模式下生长器件的有源区来获得，这导致带结构势波动，从而导致有效的辐射复合。预期IQE值将为70%或更高。LED器件将是简并掺杂的p-SiC衬底上的倒置结构，其与空穴的偏振辅助注入一起预期导致IE 50%或更高。导电AlGaN基p型DBR将结合在衬底和有源区之间，以防止p-SiC衬底中的吸收。此外，倒置结构将允许从器件的透明n-AlGaN侧提取光，其可以纹理化以获得最大光提取，从而导致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.