Wide spectrum semiconductor light source from GaAs-bismide alloys.

该项目将探索砷化镓-双胺合金在红外波长发光二极管中的应用。含铋的砷化镓是最重的V族元素，是一种窄禁带半导体合金，具有许多有趣的物理性质和广阔的应用前景。在这个项目中，我们探索了这种材料在其中一个应用中的应用，即作为光学相干断层扫描(OCT)的光源，这是一种非侵入性的医学成像方式。由于几个原因，双胺合金对这一应用很有吸引力。由于与铋合金化相关的独特的电子结构，该材料的发光光谱比其他III-V半导体合金宽得多(~100 nm)。发射光谱的宽度控制着OCT的分辨率，因此是OCT光源的重要品质因数。这种反常行为的原因是，在某些方面，铋的行为是一种杂质，而不是合金元素。此外，当沉积在GaAs衬底上时，双酰胺合金可以覆盖OCT感兴趣的整个850-1600 nm波长范围。它与成熟的GaAs/AlGaAs激光器技术兼容，能适应高功率工作，并有成熟的制造工艺。光源应用只是双胺合金众多有前途的应用之一。这项提案中的工作将促进对增长的了解

This project will explore the use of gallium arsenide-bismide alloys in infrared wavelength light emitting diodes. GaAs alloyed with bismuth, the heaviest group V element, is a narrow bandgap semiconductor alloy with interesting physical properties and a number of promising applications. In this project we explore the application of this material in one of these applications, namely as a light source for optical coherence tomography (OCT), a non-invasive medical imaging modality. The bismide alloys are attractive for this application for several reasons. Due to the unique electronic structure associated with Bi-alloying, the light emission spectrum from the material is much broader than for other III-V semiconductor alloys (~100nm). The width of the emission spectrum controls the resolution in OCT and is therefore an important figure of merit for an OCT light source. The reason for this anomalous behaviour is that Bi behaves in some respects as an impurity rather than as an alloying element. In addition when deposited on GaAs substrates the bismide alloys can cover the entire 850-1600 nm wavelength range of interest for OCT. Being compatible with the well established GaAs/AlGaAs laser technology they are amenable to high power operation and a mature manufacturing technology is available. The light source application is only one of a number of promising applications for the bismide alloys. The work in this proposal will advance the state of knowledge of growth