Resonant cavity detectors and their materials, for spectroscopic chemical detection

该项目的目标是创造和研究用于光谱检测的红外探测器，主要针对需要比目前可用的更灵敏的探测器的物质。探测器将增强谐振腔(在有源层的两侧放置一个反射镜)，以提高光谱选择性。这些探测器还处于研究领域，在一些重要的波长范围内还没有实现它们的验证，它们的工作以及理论和实验数据的一致性也是一些悬而未决的问题。例如，该项目的一个重要目标是从实验上证明，谐振腔探测器的最大灵敏度可以超过标准探测器的理论极限，正如预测的那样。这一点还没有实现。如果把这个项目归结为两个问题，那就是“谐振腔探测器能否在短波和长波红外波段实现”和“它们的测量性能能否与它们的理论完全一致，或者这是否需要改进”。探测器将由学生建模和设计。他们将通过分子束外延(MBE)生长它，使用用于短波探测器(1.4至3.0微米)的InGaAsSb吸收体，用于中波探测器(3至5微米)的InAsSb或超级晶格吸收体，以及用于长波探测器(8至12微米)的超级晶格吸收体。它们将在我们的洁净室中进行处理，并在实验室中对泄漏电流、光谱响应和量子效率进行表征。学生将完成所有这些工作，并发布他们的结果。我们期望这一博士学位能够促进对所用材料的理解，以及对谐振腔探测器的物理理解，特别是对其泄漏电流机制的理解。这也将进一步提高对传统探测器器件物理的理解，谐振腔设计正试图将其推向极限。EPSRC研究领域：光子材料和器件

The project is aiming to create and study infrared detectors for spectroscopic detection, primarily aimed at substances that require more sensitive detectors than are currently available. The detectors will be resonant cavity enhanced (a mirror is placed either side of the active layer) to improve spectral selectivity. These detectors are still in the research realm, with their demonstration yet to be achieved in some important wavelength ranges, and some open questions regarding their operation and the reconciliation of theory and experimental data. For example one important target of the project is to experimentally prove that the maximum sensitivity of resonant cavity detectors can be above the theoretical limit for standard detectors, as it is predicted to be. This has not yet been achieved. If the project were condense to two questions they would be "can resonant cavity detectors be achieved in the short and long wave infrared" and "can their measured performance be fully reconciled with their theory, or does this need modifying". The detectors will be modelled and designed by the student. They will grow it by molecular beam epitaxy (MBE) using InGaAsSb absorbers for short wave detectors (1.4 to 3.0 micro meters), InAsSb or super lattice absorbers for mid wave detectors (3 to 5 micro meters) and super lattice absorbers for long wave detectors (8 to 12micro meters). They will process in our cleanroom and characterise thein the lab for leakage current, spectral response and quantum efficiency in particular. The student will complete all this work, publishing their result. We expect this PhD to advance understanding in the materials used and the physical understanding of resonant cavity detectors, in particular their leakage current mechanisms. This will also by extension improve understanding of conventional detector device physics, which the resonant cavity design is attempting to push towards a limit.EPSRC research area: photonic materials and devices