ASCENT: Optically-Driven Ultra-Wide-Bandgap Power Electronics for Grid Energy Conversion

发电占美国温室气体排放量的30%。电网中可再生能源的整合是实现零碳排放目标的关键，这需要增加电力电子设备的部署，这些电子设备具有卓越的电力可扩展性和超越最先进水平的更高频率。目前，电网电力电子系统的可扩展性受到电源级和驱动级之间电磁干扰的限制，这使得许多器件的串联和并联堆叠变得困难。另一方面，由于高压功率半导体器件的开关速度慢，频率受到限制。该NSF项目旨在通过部署新兴的超宽带隙（UWBG）半导体，同时推进电网电力电子的开关频率和功率可扩展性。这一目标将通过利用UWBG材料独特的电子和光学特性，开发新一代由光信号驱动的高压、超快UWBG器件，以及辅助电路、深紫外光学系统和封装技术的协同创新来实现。该项目的智力优势包括建立关于纳米材料、UWBG器件、光学系统、封装和电路的知识库，以实现设想的光驱动、emi免疫电网电力电子设备。该项目更广泛的影响包括在纳米技术、半导体、微电子和电力电子领域培训未来的学生，以及增加多样性和支持来自代表性不足群体的学生，重点是促进女性科学家和工程师的教育。该项目还将用于支持K-12学生的外展活动。该项目的目标是解决纳米材料，UWBG器件，光学系统，封装和电路方面的基础知识差距，以实现用于电网应用的光驱动，高度集成，超快，emi免疫，高效的电力电子设备。该系统愿景建立在新兴半导体氧化镓（Ga2O3）的基础上，其带隙为4.6 eV，临界电场是氮化镓或碳化硅的两倍，是硅的20倍，使其成为功率和深紫外光子器件的理想候选者。本项目将重点开展以下四个方面的研究工作：(1)开发一种新型的Ga2O3光驱动功率开关，与硅晶闸管相比，其开关频率提高了几个数量级，光功率降低了几个数量级。(2)针对UWBG器件，探索包括光源、光波导和光纤到芯片耦合在内的集成DUV光系统。(3)探索先进的封装设计，在保持光纤连接完整性的同时，实现电场抑制、低热阻和低电感。(4)开发一种自给自足的辅助电源，从器件电压和电流中提供驱动电源，从而避免任何外部辅助电源。最后，将在电感开关测试和中压固态断路器中评估光驱动、外部辅助无电源、高度集成的UWBG系统的功能。该奖项反映了美国国家科学基金会的法定使命，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。

Electricity generation is responsible for 30% of U.S. greenhouse gas emission. Integration of renewable energy sources in electricity grids is key to reaching the goal of zero carbon emission, which requires the increased deployment of power electronics that possesses superior power scalability and higher frequency beyond the state of the art. Currently, the scalability of grid power electronics is limited by the electromagnetic interference (EMI) between the power and driving stages, which makes it difficult to stack many devices in series and in parallel. On the other hand, the frequency is limited by the slow switching speed of high-voltage power semiconductor devices. This NSF projects aims to concurrently advance the switching frequency and power scalability of grid power electronics through the deployment of an emerging ultra-wide-bandgap (UWBG) semiconductor. This goal will be achieved by leveraging the unique electronic and optical properties of UWBG materials to develop a new generation of high-voltage, ultra-fast UWBG devices that are driven by optical signals, as well as synergetic innovations in auxiliary circuits, deep UV optical systems, and packaging techniques. The intellectual merits of the project include establishing the knowledge base regarding the nanomaterials, UWBG devices, optical systems, packaging, and circuitry to enable the envisioned optically-driven, EMI-immune grid power electronics. The broader impacts of the project include training future students in the fields of nanotechnology, semiconductors, microelectronics, and power electronics, as well as increasing diversity and supporting students from underrepresented groups, with an emphasis on promoting the education of women scientists and engineers. This project will also be utilized to support the outreach activities for K-12 students.The objective of this project is to address the fundamental knowledge gaps in nanomaterials, UWBG devices, optical systems, packaging and circuitry to enable an optically-driven, highly-integrated, ultrafast, EMI-immune, highly-efficient power electronics for grid applications. This system vision builds upon an emerging semiconductor, gallium oxide (Ga2O3), which has a bandgap of ~4.6 eV and a critical electric field twice that of gallium nitride or silicon carbide and ~20 times that of silicon, rendering it an ideal candidate for power and deep UV photonic devices. This project will focus on research activities in the following four aspects: (1) A new Ga2O3 optically-driven power switch will be developed, which allows for orders of magnitude higher switching frequency and lower optical power as compared to optical silicon thyristors. (2) An integrated DUV optical system including light sources, optical waveguide and fiber-to-chip coupling will be explored for UWBG devices. (3) An advanced packaging design will be explored to realize the electric field mitigation, low thermal resistance, and low inductance, while maintaining the integrity of the optical fiber connections. (4) A self-sustained auxiliary power supply will be developed that will feed the driving power from the device voltage and current, thus obviating any external auxiliary power supply. Finally, the functionalities of the optically-driven, external-auxiliary-power-free, highly-integrated UWBG system will be evaluated in inductive switching tests and a medium-voltage solid-state circuit breaker.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.