Wide spectrum semiconductor light source from GaAs-bismide alloys.

本计画将探讨砷化镓-铋化物合金在红外线波长发光二极体之应用。GaAs与最重的V族元素铋合金是一种具有有趣的物理性质和许多有前途的应用的窄带隙半导体合金。在这个项目中，我们探讨了这种材料在这些应用中的应用，即作为光学相干断层扫描（OCT），一种非侵入性医学成像模式的光源。由于几个原因，双酰亚胺合金对于该应用是有吸引力的。由于与Bi合金化相关的独特电子结构，该材料的发光光谱比其他III-V族半导体合金宽得多（约100 nm）。发射光谱的宽度控制OCT中的分辨率，因此是OCT光源的重要品质因数。这种反常行为的原因是Bi在某些方面表现为杂质而不是合金元素。此外，当沉积在GaAs衬底上时，双酰化物合金可以覆盖OCT所关注的整个850-1600 nm波长范围。与成熟的GaAs/AlGaAs激光技术兼容，它们可以进行高功率操作，并且可以使用成熟的制造技术。光源应用只是铋化物合金的许多有前途的应用之一。本提案中的工作将推进知识增长的状态

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