GOALI: BGaAs and BGaInAs Detectors Lattice-Matched to Silicon

非技术：基于硅的集成电路改变了现代生活。它们是微电子和数字计算机的基础。硅还被用于将光转化为电能的光电子器件，如太阳能电池和光电探测器，或将电能转化为光的光电设备，如发光二极管和激光。然而，硅只对可见光和一小部分红外光谱敏感。此外，硅基设备探测光的速度也从根本上受到了限制。该项目将研究一种新的含硼材料家族，这种材料对更广泛的红外光敏感，同时大大提高了检测速度。这些材料的一个关键优势是它们的晶体结构与硅兼容。这使得它们可以作为高质量的晶体直接生长在硅上，并利用复杂的硅制造基础设施。该项目将演示几种类型的光电探测器，并确定测量其最终潜力所需的基本物理性质。应用包括自动驾驶车辆、通信系统和生物医学仪器。该项目还将为研究生、本科生和高中生提供独特的指导和研究经验。外展活动将包括通过课堂访问启发K-12学生，以及像科学星期四和爱迪生系列讲座这样的活动。技术：直接带隙、晶格匹配的半导体合金与硅的单片集成仍然是激光和光电探测器的光子学圣杯。由此产生的器件将使硅基光子集成电路的功能得到极大的进步，应用范围从成像系统和激光雷达，到电信、化学传感等。目前在硅上实现直接带隙材料单片集成的方法受到各种挑战，并且没有明确的途径来获得满足近红外和中红外重要新兴应用所需的晶格匹配材料。对这一关键挑战提出了一种解决方案：一种专注于硅基BGaInAs光电探测器的解决方案，这种探测器的截止波长可以从1微米到5微米。它的基础是GaP/Si衬底的商业可用性，以及该团队最近的成功展示：(1)在GaP和GaP/Si上成功地生长了高达~22%的创纪录的高硼含量，几乎足以与硅进行晶格匹配；(2)作为光电探测器和发光二极管的原型pn和Pin BGA(In)；以及(3)成功地在GaP和GaP/Si上成功地生长了相干直接带隙BGaAs。虽然重点将放在实现直接带隙晶格匹配的光电探测器上，但重要的是要注意到，这种方法也适用于发射体。该项目将把得克萨斯大学奥斯汀分校的专业知识与外延BGA(In)作为光电探测器的分子束外延生长和器件制造与紫晶研究公司的中红外NBN探测器专业知识结合起来：(1)在硅上实现高性能的pn结和管脚结光探测器，(2)照明和量化硅和砷化镓上可访问的带隙和带对齐，以及(3)利用这些特性来设计和展示3-5微米范围内的硅基NBN探测器。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Nontechnical:Integrated circuits based on silicon have transformed modern life. They are the basis of microelectronics and digital computers. Silicon has also been used for optoelectronics devices that convert light into electricity, such as solar cells and photodetectors, or electricity into light, such as light-emitting diodes and lasers. However, silicon is sensitive only to visible light and a limited portion of the infrared spectrum. Also, the speed with which silicon-based devices can detect light is fundamentally limited. This project will study a new family of boron-containing materials that are sensitive to a broader range of infrared light as well as greatly increased speed of detection. One key advantage of these materials is that their crystal structure is compatible with silicon. This allows for them to be grown as high-quality crystals directly on silicon and take advantage of the sophisticated silicon manufacturing infrastructure. This project will demonstrate several types of photodetectors, as well as determine the fundamental physical properties necessary to gauge their ultimate potential. Applications include autonomous vehicles, communication systems, and biomedical instrumentation. The project will also provide unique mentoring and research experiences for graduate, undergraduate, and high school students. Outreach activities will include inspiring K - 12 students through classroom visits, as well as events like Science Thursdays and the Edison Lecture Series.Technical:Monolithic integration of direct bandgap, lattice-matched, semiconductor alloys with silicon remains a holy grail of photonics for both lasers and photodetectors. The resulting devices would enable tremendous advances in functionality for silicon-based photonic integrated circuits, with applications ranging from imaging systems and laser radar, to telecommunications, chemical sensing, etc. Current approaches towards monolithic integration of direct bandgap materials on silicon suffer from a variety of challenges, and there is no clear path to the lattice-matched materials needed to address important emerging applications in the near- and mid-infrared. A solution to this critical challenge is proposed: one focused on BGaInAs photodetectors on silicon that could span cutoff wavelengths from 1 to 5 microns. It is underpinned by the commercial availability of GaP/Si substrates, as well as the team's recent success demonstrating (1) record high boron contents up to ~22% into GaAs, nearly sufficient to lattice-match with silicon, (2) prototype pn and pin BGa(In)As photodetectors and light emitting diodes on GaAs, and (3) successful initial growths of coherent direct bandgap BGaAs on GaP and GaP/Si. While the focus will be on realizing direct bandgap lattice-matched photodetectors, it is important to note this approach will be applicable to emitters as well. This project will couple the expertise of the University of Texas at Austin with molecular beam epitaxial growth and device fabrication of epitaxial BGa(In)As photodetectors with the mid-infrared nBn detector expertise of Amethyst Research Inc. to: (1) realize high-performance pn- and pin-junction photodetectors on silicon, (2) illuminate and quantify the accessible bandgaps and band alignments on silicon and GaAs, and (3) use these properties to design and demonstrate silicon-based nBn detectors in the 3-5 micron range.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.