CDS&E: Coupled Electro-Thermal Transport in Two-Dimensional Materials and Heterostructures

该项目通过计算和数据支持的科学与工程计划资助，由材料研究部的凝聚态物质和材料理论计划以及化学，生物工程，环境，非技术性总结该奖项支持计算研究的发展和应用的模拟工具，以模拟运输系统，二维（2D）材料中的电荷和热载体。2D材料是一组广泛的新型材料，其形式为厚度仅为一个或几个原子的原子级薄片。由于其极薄的厚度，这种材料作为未来节能纳米电子和能源设备的平台具有巨大的前景，这可能使极其密集的集成电路以及可穿戴和多功能电子产品成为可能。材料的电子和热性能不仅相互耦合，而且相互依赖：电阻随着温度的增加而急剧增加，这反过来又会增加散热，从而产生浪费能量并限制性能的热点。这在2D材料中尤其明显，其原子薄度和与环境的相对弱耦合可能会成为散热的瓶颈。在这个项目中，PI将开发和发布一个代码，同时处理各种科学和技术相关的二维材料中的电荷和热载体的动力学。将要制定的守则将免费向社区传播，同时沿着维持一个专门的论坛和文件网站。该奖项还支持PI的教育和推广活动，包括培训和指导下一代计算材料科学家，并通过重新设计核心材料课程，招募科学，数学和工程学科的代表性不足的学生，并创建免费的在线教育模块，教本科生高-该奖项支持计算研究的发展和应用的模拟工具，以解决耦合玻尔兹曼输运方程的电子和二维（2D）材料中的声子。模拟2D纳米结构内部的热耗散需要电子和热的双向耦合处理，后者由声子传输。从第一性原理计算电子-声子耦合和使用从头算输入求解电子和声子玻尔兹曼输运方程现在已经完全成熟。然而，迫切需要一个平台，将能够研究非等温传输，其中电子和声子群体同时模拟，以便跟踪由电子-声子耦合产生的声子，并将其分布/温度反馈到电子传输中，反之亦然。为了满足这一需求，PI将开发并发布一个名为CelphonBTE 2D的代码，用于二维材料和异质结构的双向耦合电子-声子玻尔兹曼输运模拟。该代码将建立在第一原理数据的基础上，以实现对现实应用的预测模拟。将要开发的代码将通过nanoHUB传播，该中心将托管源代码并跟踪使用情况，沿着一个专门的论坛和文件网站。该奖项还支持PI的教育和推广活动，包括培训和指导下一代计算材料科学家，并通过重新设计核心材料课程，招募STEM学科代表性不足的学生，并创建免费的在线教育模块，教本科生高-该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project is funded through the Computational and Data-Enabled Science and Engineering program by contributions from Condensed Matter and Materials Theory program of the Division of Materials Research and the Thermal Transport Processes program of the Division of Chemical, Bioengineering, Environmental, and Transport Systems.NONTECHNICAL SUMMARYThis award supports computational research for the development and applications of a simulation tool to model the transport of charge and heat carriers in two-dimensional (2D) materials. 2D materials are a broad cohort of novel materials in the form of atomically thin sheets having a thickness of only one or a few atoms. Owing to their ultimate thinness, such materials hold tremendous promise as a platform for future energy-efficient nanoelectronic and energy devices, which may enable extremely dense integrated circuits, and wearable and multifunctional electronics. Electronic and thermal properties of materials are not only mutually coupled but strongly interdependent: electrical resistance increases drastically with temperature, which, in turn, increases heat dissipation, creating hot spots that waste energy and limit performance. This is particularly pronounced in 2D materials, whose atomic thinness and relatively weak coupling to the environment may present a bottleneck to heat removal. In this project, the PI will develop and release a code that treats the dynamics of charge and heat carriers concurrently in various 2D materials of scientific and technological relevance. The code to be developed will be disseminated freely to the community, along with maintaining a dedicated website for forums and documentation. This award also supports the PI's educational and outreach activities, which include training and mentoring the next generation of computational materials scientists and introducing computational science to students across levels, by redesigning core materials courses, recruiting underrepresented students in science, math, and engineering disciplines, and creating free online educational modules to teach undergraduate students high-performance and parallel computing.TECHNICAL SUMMARYThis award supports computational research for the development and applications of a simulation tool to solve the coupled Boltzmann transport equations for electrons and phonons in two-dimensional (2D) materials. Simulating thermal dissipation inside 2D nanostructures requires a two-way coupled treatment of electrons and heat, the latter being transported by phonons. Computing electron-phonon coupling from first principles and solving the electron and phonon Boltzmann transport equations using ab initio inputs has now reached full maturity. However, there is a critical need for a platform that will enable studying non-isothermal transport, where electron and phonon populations are simulated concurrently so that phonons generated by electron-phonon coupling are tracked and their distribution/temperature fed back into electron transport and vice versa. To address this need, the PI will develop and release a code, called CelphonBTE2D, for two-way coupled electron-phonon Boltzmann transport simulation of 2D materials and heterostructures. The code will build on first-principles data to enable predictive simulation for realistic applications. The code to be developed will be disseminated via the nanoHUB, which will host source code and track usage, along with a dedicated website for forums and documentation. This award also supports the PI's educational and outreach activities, which include training and mentoring the next generation of computational materials scientists and introducing computational science to students across levels, by redesigning core materials courses, recruiting underrepresented students in STEM disciplines, and creating free online educational modules to teach undergraduate students high-performance and parallel computing.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.