ASCENT: Reducing greenhouse emissions with ultra-efficient High-Voltage Monolithic Bidirectional Transistors

温室气体排放是造成全球气候动态变化的主要因素。根据美国环境保护署的数据，温室气体排放总量的50%分别与发电（25%）和运输（27%）有关。这就迫切需要有效利用可用电力，因为到2030年，预计总发电量的80%将通过电力电子设备。随着现代电网和交通的电气化程度不断提高，超高效双向电力流正迅速成为一种新兴需求。电网中存在双向潮流（例如，从消费者到电网和从电网到消费者的太阳能，消费者作为存储和分配元件），电动汽车（例如，从汽车到电网和电网到汽车，汽车到另一辆汽车，汽车作为电力的来源和消费者），工业电机驱动器，固态变压器，数据中心电源，电梯驱动器，DC微电网，所有这些应用都推动了电力电子在所有形式的电力消耗和生产中的快速发展;因此，它们的结构必须是可持续的，紧凑的，并且它们可以高效地运行。然而，现有的电路解决方案以及支持双向功率流的半导体器件导致占用空间大、效率降低和容错能力低。NSF的这项提案旨在采用材料、器件和电路协同设计方法来同时解决半导体器件和电路的挑战。我们提出利用具有适当设计的半导体晶体管的电路架构，例如矩阵转换器（MC）和电流源逆变器（CSI），即，双向晶体管，以提供一个有凝聚力的解决方案。双向晶体管具有在两个方向上阻断电压和传导电流的能力。通过我们的多抽象层次的合作研究，新型材料和双向器件的合成和制造步骤将被开发，双向晶体管操作的器件和电路级的理解将获得和这些设备的性能在MC和CSI逆变器拓扑将被证明和基准。这项研究工作将与教育和劳动力发展活动以及扩大K-12，大学预科和大学生的参与程度相配合。这项提案的主要目标是利用宽带隙材料（WBG）和超宽带隙（UWBG）材料开发超高效，高电压单片双向晶体管（MBDT）将被用于有效的双向功率流使能电路。本项目将围绕这些研究目标展开。1)第一个基于UWBG的单片双向晶体管（MBDT）的演示。2)通过材料-器件协同设计，同时提高GaN单片双向晶体管的性能和可制造性。3)开发一种独特的高导电性多沟道UWBG（AlGaN）材料，与现有解决方案相比，其导电损耗可达10倍。4)发展对物理现象的全面理解，电子俘获，滞后，击穿机制，电流崩溃，热限制，鲁棒性和单片双向晶体管的可靠性。5)演示转换器拓扑结构，并通过引入单片双向晶体管与现有解决方案进行效率基准测试。我们的劳动力教育，培训和发展工作将包括通过促进实习机会，午餐研讨会网络和课程重新设计来促进学生与行业的合作。此外，我们将与行业和当地麦迪逊地区技术学院合作，设计课程，以满足不断增长的技术人员和操作人员的需求。我们将通过与代表性不足和贫困的大学预科学生开展外展活动来扩大参与，并提高K-在威斯康星州科学节和工程博览会上，通过一项新活动，对智能能源的选择及其对环境的影响进行了12级评价。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的评估，被认为值得支持。影响审查标准。

Greenhouse gas emissions are the primary contributors for the change in global climate dynamics. According to the U.S. Environment and Protection Agency, 50% of the total greenhouse gas emissions sources are tied to electricity generation (25%) and transportation (27%), respectively. This places an urgent need for efficient utilization of available electric power, considering 80% of the total generated electric power is expected to flow through power electronics by 2030. With the rising electrification of the modern grid and transportation, ultra-efficient bidirectional power flow is fast becoming an emerging requirement. Bidirectional power flow can be witnessed in a grid (for example, solar energy from consumer to grid and from grid to consumer, consumer as storage and distribution element), electric car (for example, from car to grid and grid to car, car to another car, car as a source and consumer of electric power), industrial motor drives, solid-state transformers, data center power supplies, elevator drives, DC microgrids, energy storage, etc. All these applications drive the rapid expansion of power electronics across all forms of electrical power consumption and production; thus, it is critical that their construction is sustainable, compact, and they operate efficiently. However, incumbent circuit solutions as well as semiconductor devices that support bidirectional power flow result in large footprint, reduced efficiency, and low fault tolerance. This NSF proposal aims to take a materials, devices, and circuit co-design approach to tackle both semiconductor device and circuit challenges simultaneously. We propose to utilize circuit architectures such as matrix converters (MCs) and current source inverters (CSIs) with suitably designed semiconductor transistors, i.e., bidirectional transistors, to present a cohesive solution. Bidirectional transistors have the capability to block voltage and conduct current in both directions. Through our multi-abstraction level collaborative research, novel material and bidirectional device synthesis and fabrication steps will be developed, device and circuit level understanding of bidirectional transistor operation will be gained and the performance of these devices in MC and CSI inverter topologies will be demonstrated and benchmarked. This research effort will be complemented with efforts for education and workforce development activities as well as broadening participation amongst K-12, pre-college, and college students.The key objective of this proposal is to leverage wide bandgap materials (WBG) and ultra-wide-bandgap (UWBG) materials to develop ultra-efficient, high-voltage monolithic bidirectional transistor (MBDT) to be utilized in efficient bidirectional power flow enabling circuits. This project will focus on these research goals. 1) Demonstration of the first UWBG based monolithic bidirectional transistors (MBDT). 2) Enhancing the performance of GaN Monolithic Bidirectional Transistor and manufacturability simultaneously by material-device co-design. 3) Development of a unique high-conductivity multi-channel UWBG (AlGaN) material development which can lead to 10x conduction losses compared to incumbent solutions. 4) Develop comprehensive understanding of physical phenomenon electron-trapping, hysteresis, breakdown mechanisms, current collapse, thermal limits, robustness, and reliability in monolithic bidirectional transistors. 5) Demonstration of converter topologies and benchmarking efficiency with the introduction of monolithic bidirectional transistors compared to incumbent solutions. Our workforce education, training, and development efforts will include fostering student-industry collaboration by facilitating internship opportunities, lunch seminar networking, and curriculum redesign. Additionally, we will work with industry and local Madison area technical colleges to design courses to meet rising technician and operator needs. We will broaden participation by performing outreach activities with under-represented and underprivileged pre-college students and increase awareness at the K-12 level on smart energy choice and their impact on the environment with a new activity at the Wisconsin Science Festival and Engineering Expo.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.