新型稀铋近红外宽光谱发光二极管的基础研究

Light source with a broadband spectrum plays a key role in optical coherent tomography (OCT). The spatial resolution of an OCT system is inversely proportional to the full width at half maximum (FWHM) of the spectrum. The best theoretical resolution of a commercial light source for OCT is 3.6 μm. Our group demonstrated successful growth of high quality InPBi single crystal for the first time by molecular beam epitaxy in 2013. The InPBi reveals strong photoluminescence at room temperature with a record FWHM of 690 nm, larger than the best reported value of 513 nm from self-organized InAs quantum dots grown on GaAs substrate. The corresponding theoretical resolution value reaches 1 μm. Aiming at demonstrating electrically pumped InPBi light emitting diode (LED), we intend in this proposal to epitaxially grow In(GaAl)PBi nanostructures using gas-source molecular beam epitaxy. By optimizing growth parameters and structural design, we shall demonstrate photoluminescence at about 1.4 μm with a FWHM of 850 nm, corresponding to a theoretical resolution of 1 μm. We shall also study the carrier loss mechanism and thermal stability of LED, optimize the LED design and demonstrate working LED at room temperature with a FWHM larger than 400 nm. Implementation of this project will keep China as the world leading position in this research field.

宽光谱光源是光学相干层析成像技术中的关键部件，成像技术中的轴向分辨率与半峰宽成反比,目前商用宽光谱光源的最佳分辨率为3.6微米。申请人所在的研究组于去年在世界上首次采用分子束外延方法合成高性能InPBi单晶材料，该材料在室温下展现很强的近红外光，半峰宽达到690纳米，超过GaAs基上外延生长InAs量子点的513纳米的世界纪录，应用于光学相干层析成像技术时理论轴向分辨率可达1.5微米。本项目将以制作电泵In(GaAl)PBi发光二极管为目标，采用气态分子束外延设备在InP上外延In(GaAl)PBi纳米结构材料，通过优化材料参数和有源区结构，获得室温中心波长约1.4微米、半峰宽为850纳米的光致发光，理论上的轴向分辨率达到1微米；通过研究光电损耗机理和材料热稳定性，设计In(GaAl)PBi发光二极管结构，演示半峰宽达400纳米的室温电泵In(GaAl)PBi发光二极管，保持我们的领先地位

宽光谱光源是光学相干层析成像技术中的关键部件，成像技术中的轴向分辨率与半峰宽成反比,目前商用宽光谱光源的最佳分辨率为3.6微米。申请人所在的研究组在世界上首次采用分子束外延方法合成高性能InPBi单晶材料，该材料在室温下展现很强的近红外光，半峰宽超过GaAs基上外延生长InAs量子点的513纳米的世界纪录，应用于光学相干层析成像技术时理论轴向分辨率可达1.5微米。本项目以制作电泵In(GaAl)PBi发光二极管为目标，采用气态分子束外延设备在InP上外延InPBi纳米结构材料，通过优化材料参数和有源区结构，获得了室温中心波长约1.4微米、半峰宽为700纳米的光致发光；首次合成了InGaPBi新材料；演示了世界首个InPBi发光二极管，保持了在该领域我们的领先地位。在本项目的支持下，共发表标注本项目的SCI文章16篇，申请国家发明专利2项。协助培养了博士研究生两名。