CAREER: Towards highly efficient UV emitters with lattice engineered substrates

这一职业项目的目标是显著提高发光二极管在紫外线范围内的效率，特别是在现有方法效率突然下降的范围内。一种新的柔性材料将被使用，这将有助于改善这类紫外线发射器面临的与应变相关的问题，这些材料还将把光引导到特定方向，以有效地从设备中提取光。将采用实验和理论研究相结合的方法来展示光提取、材料和器件级别的改进，所有这些都将导致比目前的解决方案提高高达10倍。所开发的结构不仅将增强现有产品的能力，还将在医学领域实现全新的应用-皮肤病治疗和心血管/眼科手术、农业-食品储存和农业、卫生-空气、地表和水；高效设备的能源节约，从而实现可持续性，并最终提高银行和身份证安全系统的可靠性。更广泛的影响活动将涉及评估拟议的研究和大规模采用紫外线发射器而不是现有汞灯对生物多样性、医药和粮食安全等各个领域的影响。通过利用教师研究经验在教育系统的早期介绍半导体及其社会影响，建议在高中课程中加入一个关于半导体是有趣的模块。建议在不同级别--大学预科、本科生和研究生--进行不同类型的劳动力培训，以填补由于《鼓励芯片法》相关举措而导致的国家一级劳动力短缺的需求。计划与农业社区开展社区参与活动，以提高对紫外线发射体以及它们如何提高国家粮食安全的认识。技术描述：这个职业项目旨在解决III-氮化物固态发射体在280-365 nm紫外线发射波长范围内的外部量子效率差距，以实现新的高功率紫外线发光二极管制度。在这个波长范围内，器件的效率与波长有很大的依赖关系，这将被建议的解决方案解耦。研究方法将涉及基于多孔性半导体的机械顺应性和反射性基板的开发，以重新定义用于设计基于III族氮化物的器件外延结构的临界厚度指标，以实现预期的效率提高一个数量级。利用新的量子井和载流子注入层，将采用新的方法来合成多孔材料，并实现半导体反射器。将开发机械、光学和光电计算模型，以指导实验探索，并加强对所使用的外延结构的力学和物理的理解。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

The objective of this CAREER project is to significantly improve the efficiency of light emitting diodes in the ultraviolet range, especially in those ranges where incumbent methods show an abrupt drop in efficiency. A new class of flexible materials will be used that will help improve strain related issues faced by this class of ultraviolet emitters, and these materials will also direct light in a specific direction to efficiently extract light out of the device. A combination of experimental and theoretical investigations will be employed to demonstrate light extraction, material, and device level improvements all resulting in up to 10x improvement over current solutions. The developed structures will not only enhance the capabilities of currently available products but will also enable completely new applications in the field of medical science – skin disease treatments and cardiovascular/eye surgeries, agriculture – food storage and farming, sanitization- air, surface and water; energy savings from efficient devices resulting in sustainability and finally improve reliability of security systems used in banks and for ID cards. The broader impacts activities will involve assessing the impact of proposed research and large-scale adoption of ultraviolet emitters over incumbent mercury lamps on various fields such as biodiversity, medicine and food security. Incorporation of a module on ”semiconductors are fun” in high school curriculum is proposed by leveraging the research experience for teachers program to introduce semiconductors and their societal impacts early on in the education system. Different kinds of workforce trainings at various levels – precollege, undergraduate and graduate level are proposed to fill the national level workforce shortage demand owing to the encouraging CHIPS Act related initiatives. Community engagement activities are planned with farming communities to generate awareness about ultraviolet emitters and how they can enhance national food security.Technical description: This CAREER project aims to address the gap in external quantum efficiency of III- nitride solid state emitters in the ultraviolet emission wavelength range of 280-365 nm to enable a new regime of high-power ultraviolet light emitting diodes. There is a sharp wavelength dependence on the efficiency of devices in this wavelength range, that will be decoupled by the proposed solution. The research approach will involve the development of mechanically compliant and reflective substrates based on porous semiconductors, to redefine the critical thickness metrics used to design group III-nitride based device epitaxial structures to achieve a projected efficiency improvement by an order of magnitude. Using novel quantum well and carrier injection layers, new methods of synthesis of porous materials, and implementation of semiconductor reflectors will be employed. Mechanical, optical and opto-electrical computational models will be developed to guide experimental explorations and enhance the understanding of the mechanics and physics of the epitaxial structures being used.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.