SGER: Mid-Infrared Interband Cascade Photodetectors

目的：本研究的目的是探索一种新型的基于带间级联(IC)结构的中红外(IR)光电探测器，它只需调整量子井层的厚度，就可以覆盖3~12微米的宽红外光谱范围。我们的目标是在室温或热电(TE)较冷的温度下实现高性能和低噪声的IC光电探测器(专注于4-7微米)。智能优点：IC光电探测器基于一种新的工作原理，结合了非常快的子带间弛豫、用于载流子传输的带间隧道传输和相对较慢的带间跃迁的优势。这一研究将促进对IC光电探测器中载流子输运和光子吸收等物理过程的理解。与基于子带间跃迁的光电探测器不同，IC光电探测器对垂直入射辐射很敏感。此外，与传统的半导体和第二类超晶格探测器相比，IC光电探测器中的载流子传输/收集不受背景掺杂和材料质量变化的影响。因此，这项研究将为研究带间级联结构和器件中与潜在物理相关的新现象提供机会，并导致能够在室温或接近室温下工作的高性能中红外光电探测器。更广泛的影响：这项研究将在量子半导体结构和器件的设计和理解方面产生新的知识。高性能中红外光电探测器的实现将对医疗、工业、国防和国土安全等领域的应用产生重大影响。这项工作将通过固有的多学科主题为学生提供独特的教育、培训和研究机会。

Objective:The objective of this research is to explore a new class of mid-infrared (IR) photodetectors based on the interband cascade (IC) structures, which can cover a wide infrared spectral range from 3 to 12 microns by merely adjusting quantum well layer thickness. Our goal is to achieve high performance and low noise IC photodetectors (focus on 4-7 microns) at room temperature or thermoelectric (TE) cooler temperatures. Intellectual Merit:IC photodetectors are based on a new operation principle combining advantages of very fast intersubband relaxation and interband tunneling for carrier transport and relatively slow interband transitions. This research will advance the understanding of physical processes such as carrier transport and photon absorption in IC photodetectors. Unlike photodetectors based on intersubband transitions, IC photodetectors are sensitive to normal incidence radiation. Furthermore, carrier transport/collection in the IC photodetector is immune from background doping and material quality variations in contrast to conventional semiconductor and type-II superlattice detectors. Hence, this research will provide opportunity to investigate new phenomena associated with underlying physics in interband cascade structures and devices, and lead to high performance mid-IR photodetectors that can operate at or near room temperature. Broader Impacts: This research will generate new knowledge in the design and understanding of quantum semiconductor structures and devices. The realization of high-performance mid-IR photodetectors will have significant impacts on medical, industrial, defense and homeland security applications. This work will provide students unique opportunities to have education, training and research through the inherent multidisciplinary topics.