Enhancement of interfacial thermal transport through evanescent electric field mediated acoustic phonon transmission for efficient cooling of high power Gallium Nitride devices

通过瞬逝电场介导的声声子传输增强界面热传输，以实现高功率氮化镓器件的高效冷却

• 批准号: 2336038
• 负责人: Jivtesh Garg
• 金额: $ 36万
• 依托单位: University of Oklahoma Norman Campus
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2024
• 资助国家: 美国
• 起止时间: 2024-01-15 至 2026-12-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2336038&HistoricalAwards=false
• 关键词: Enhancement; interfacial; thermal; transport; through

Increasing power dissipation in electronic devices such as laptops, mobile phones and high-power Gallium Nitride (GaN) devices has led to the need for improved cooling, and to maintain device temperatures below permissible levels. A recent cooling strategy involves using a diamond substrate to cool electronic devices, due to the ultra-high thermal conductivity of diamond exceeding 2000 W/mK at 300 K. However, the interface between the diamond and the GaN electronic component has both poor interfacial bonding and structure-defects, which greatly diminish heat transfer across the interface, exacerbating the thermal management problem. The goal of this research is to explore the role of electric fields across the interface to reduce the interface thermal resistance and thus enable large enhancement of heat transfer across the electronic device-diamond substrate interface. The project will engage graduate and undergraduate students directly in the proposed research. High school and underrepresented students will be introduced to research activities through a summer-camp program and through outreach to tribal colleges in Oklahoma. It is well known that at nanometer gaps between polar dielectrics, evanescent electric fields lead to several orders of magnitude enhancement in heat transfer above the black body limit. Such enhancement in heat transfer is adequately described by continuum fluctuation-dissipation theorem, based on phonon polaritons (coupling of electric fields with optical phonons). At gaps of around 2 to 4 Angstroms, similar to those encountered across interfacial defects, a recent work demonstrated (through an atomistic formalism) that electric fields can also enable transmission of acoustic phonons, enhancing heat transfer. The project will explore such Coulomb interaction assisted acoustic phonon transmission, for enhancement of interfacial thermal conductance, using a combination of atomistic Green’s function method and classical and ab initio molecular dynamics. Simultaneously, the project will further explore materials with superior thermal conductivity relative to diamond, at nanometer to micron range length scales, through a first-principles approach based on three and four phonon scattering and an exact solution of the Boltzmann transport equation. Materials with superior thermal conductivity and improved interfacial thermal conductance will lead to next generation high power GaN devices with improved reliability and performance.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.

笔记本电脑、移动电话和高功率氮化镓 (GaN) 设备等电子设备的功耗不断增加，因此需要改进冷却，并将设备温度保持在允许的水平以下。最近的冷却策略包括使用金刚石基板来冷却。由于金刚石在 300 K 时具有超过 2000 W/mK 的超高导热率，因此可以实现很酷的电子器件。然而，金刚石与 GaN 电子元件之间的界面结合不良，并且结构缺陷，大大减少了界面上的传热，加剧了热管理问题。本研究的目的是探索界面上电场的作用，以降低界面热阻，从而大幅增强界面上的传热。该项目将让研究生和本科生直接参与拟议的研究，并通过夏令营计划和俄克拉荷马州的部落大学向代表性不足的学生介绍研究活动。众所周知，极性之间的纳米间隙电介质中，瞬逝电场导致传热增强几个数量级，超过黑体极限，这种传热增强可以通过基于声子极化激元（电场与光学声子的耦合）的连续涨落耗散定理充分描述。在大约 2 到 4 埃的间隙中，类似于界面缺陷中遇到的间隙，最近的一项工作（通过原子形式主义）证明电场也可以实现声波的传输该项目将结合原子格林函数方法和经典及从头算分子动力学，探索这种库仑相互作用辅助声学声子传输，以增强界面热导。通过基于三和四声子散射的第一原理方法以及玻尔兹曼输运的精确解，在纳米到微米范围的长度尺度上相对于金刚石具有优异的导热性具有优异导热性和改进界面导热性的材料将带来可靠性和性能更高的下一代高功率 GaN 器件。该奖项是 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查进行评估，被认为值得支持。标准。