Integrated Hot-Phonon Harvesting Barriers in High-Power Circuit Devices

高功率电路器件中的集成热声子收集势垒

• 批准号: 1332807
• 负责人: Massoud Kaviany
• 金额: $ 29.12万
• 依托单位: Regents of the University of Michigan - Ann Arbor
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1332807&HistoricalAwards=false
• 关键词: Integrated; Hot; Phonon; Harvesting; Barriers

CBET 1332807PI: Massoud Kaviany (U. Michigan)The proposed research aims to use (integrate) a novel hot phonon absorption barrier structure converting phonon energy to harvestable electric potential, in high-power electric circuits and devices. This electric potential barrier (barrier is formed by heterostructures, e.g., Al alloying, and its height matches optical phonon energy) allows only those electrons with high momentum/energy to pass through it, while the remaining electrons with lower energy will have a favorable phonon absorption condition. For the proposed example of GaN high electron mobility transistor, the expected reduction in the maximum operating temperature is as much as 40 degC at 5 W/mm Joule heating rate, and up to 20% of the phonons will be recycled corresponding to the same saving in power consumption (i.e., in-situ direct conversion of emitted phonons back to electric potential energy). The results are expected to also apply to light emitting diodes and other high-power electronics, and contribute to thermal management at atomic scale.The use of a heterobarrier, or abrupt change in material composition, in a circuit allows electricity-generated heat to boost electric potential instead of draining efficiency. Using this architecture in high-power circuits lowers the device temperature and improves the device efficiency. Electrons in a circuit gain energy by absorbing phonons, the interatomic vibrations associated with heat. In a circuit, a ?heterobarrier? may be inserted to take advantage of these excited electrons, boosting them up in electrical potential. The heterobarrier is engineered such that the increase in the band gap energy of the new material is equal to the energy given the electron by the phonons. Monte Carlo simulations based on interaction kinetics between electron and phonon show up to 19% of phonon energy converts to electric potential. This heterobarrier reverses the role of phonon from causing electric potential drop to causing potential gain.

masoud Kaviany（密歇根大学）提出的研究旨在使用（集成）一种新的热声子吸收势垒结构，将声子能量转换为可收集的电势，用于高功率电路和设备。这种势垒（势垒由异质结构形成，如铝合金，其高度与光学声子能量相匹配）只允许那些动量/能量高的电子通过，而剩余的能量较低的电子将具有良好的声子吸收条件。对于所提出的GaN高电子迁移率晶体管的示例，在5 W/mm焦耳加热速率下，最高工作温度的预期降低高达40℃，并且高达20%的声子将被回收，对应于相同的功耗节省（即发射声子的原位直接转换回电势能）。该研究结果也有望应用于发光二极管和其他高功率电子产品，并有助于原子尺度上的热管理。在电路中使用异位垒，或材料成分的突变，可以使电产生的热量提高电势，而不是降低效率。在大功率电路中使用这种架构可以降低器件温度，提高器件效率。电路中的电子通过吸收声子获得能量，声子是与热有关的原子间振动。在电路中，异质障？可以插入利用这些被激发的电子，提高它们的电势。异质势垒的设计使得新材料的带隙能量的增加等于声子给予电子的能量。基于电子和声子相互作用动力学的蒙特卡罗模拟表明，声子能量的19%转化为电势。这种异质势垒使声子的作用由引起电势下降转变为引起电势增益。