Quantum-Engineered Long-Wavelength Infrared Photodetectors

该项目的目的是加深对量子工程带间级联(IC)结构的了解，并开发高性能的长波长红外探测器(7-10？m)。这些量子工程的带间级联红外探测器(ICIP)将在高温下工作，具有高探测率D*(~109琼斯或更高)的热电制冷器(200K)。智能的优点是将离散的吸收体系结构集成在量子工程结构中，以形成基于新原理的探测器，该新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和相对较慢的带间跃迁的优点。利用分立的吸收体系结构，ICIP避开了扩散长度的限制，并且在不影响其吸收量子效率的情况下适用于高速运行。此外，掺杂在ICIP中是不必要的，但可以作为一种手段来操纵载流子浓度和传输，而不会形成传统的耗尽区。通过消除该耗尽区，在ICIP中抑制了肖克利读出霍尔产生电流。因此，该项目将提供机会来研究与量子工程结构和器件的基本物理相关的新现象。更广泛的影响是在量子工程半导体结构和器件的设计和理解方面产生尖端知识；以及在许多工业、地球科学、空间探索以及国防和国土安全应用中实现长波长红外光谱中的高性能和低噪声光电探测器。该项目将为学生提供在多学科主题上进行教育、培训和研究的独特机会。该项目将促进教师和学生参与全州范围内的教育推广活动。

The objective of this program is to advance the understanding of quantum-engineered interband cascade (IC) structures and to develop high-performance long-wavelength infrared photodetectors (7-10 ?Ým). These quantum-engineered interband-cascade infrared photodetectors (ICIPs) will operate at elevated temperatures accessible by thermoelectric coolers (200 K) with high detectivity D* (~109 Jones or better). The intellectual merit is the integration of the discrete absorber architecture within a quantum engineered structure to form a detector based on new principles that combine the advantages of very fast intersubband relaxation, interband tunneling for carrier transport, and relatively slow interband transitions. With the discrete absorber architecture, ICIPs circumvent diffusion-length limitations and are feasible for high-speed operation without compromising their absorption quantum efficiency. Also, doping is unnecessary in ICIPs, but can be used as a means to manipulate carrier concentrations and transport without forming a conventional depletion region. By eliminating this depletion region, the Shockley-Read-Hall generation current is suppressed in ICIPs. Hence, this project will provide opportunities to investigate new phenomena associated with the underlying physics of quantum-engineered structures and devices.The broader impacts are the generation of cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures and devices; and the realization of high-performance and low-noise photodetectors in the long-wavelength infrared spectrum for many industrial, earth science, space exploration, and defense and homeland security applications. This project will offer students unique opportunities to pursue education, training and research in multidisciplinary topics. This project will promote the participation of faculty and students in statewide educational outreach activities.