中红外2-3微米InAsSb/InP量子点激光器

Self-assembled InAsSb/InP quantum dot lasers can cover their wavelength in the mid-infrared regions of 2-3μm,which have very important applications in the fields of military, molecular spectroscopy,infrared gas detection and biomedical surgery.In this project, we will study the growth conditions of self-assembled InAsSb/InP quantum dot by gas source molecular beam epitaxy(GSMBE) and the fabricating processes of laser diodes to obtain a valuable methold to adjust the emission wavelength and improve the performance of laser diodes.The nucleation mechanism of InAsSb/InP will be studied by investigating the growth kinetics. At the same time, the growth conditions of InAsSb/InP quantum dot(such as growth temperature, growth rate and the composition of Sb in the ternary InAsSb) will be systematically studied, which have great impacts on the properties of quantum dots, e.g., densities of dots, emission wavelength, uniformities and stability of quantum dots.Finally, optimized growth conditions for high optical quality of InAsSb/InP quantum dot will be obtained.The InAsSb/InP quantum dot lsers with emission wavelength in the range of 2-3μm will be fabricated. We will solve the challenging problems in fabricating InAsSb/InP quantum dot lasers, providing their emission wavelength in the range of 2-3μm. The performances of laser diodes, i.e. optical properties（output power, stability, modulation and so on）and electrical characterisitcs will be investigated intensively.New phsical phenomenons may be discovered by analyzing the experimental data. We also study the relationships between peoperties of InAsSb/InP quantum dot and characterisics of laser diode to achieve good perforamnces of laser diode.By further optimizing the growth conditions of quantum dot and fabricating processes of laser,the InAsSb/InP quantum dot laser can operate at room temperature with emission wavelength in the range of 2-3μm.

自组装InAsSb/InP量子点激光器波长能够覆盖2-3微米，在军事、分子光谱、红外气体检测和生物医学等领域有着非常重要的应用前景。本项目对气源分子束外延技术自组装生长InAsSb/InP量子点材料的生长方法与器件制备工艺展开研究，探索如何有效地控制材料发光波长和提高激光器性能。通过对量子点结构生长动力学研究，阐明InAsSb/InP量子点的生长机制，对影响量子点尺寸、面密度、发光波长、均匀性和稳定性的生长条件进行深入探讨,获得有效的量子点材料生长方法；在此基础上,通过对器件制作的关键工艺研究，研制出2-3微米激光器，对器件光学特性（如输出、调制、稳定性和低温特性等）和电学特性进行细致深入研究，挖掘其中的物理内涵和规律；根据器件性能反馈，开展材料与器件性能关系研究，进一步优化材料结构和器件制备工艺，提高器件性能,研制出室温工作的2-3微米激光器。

中红外2-3微米激光器在军事、分子光谱、气体检测和生物医学等领域有着重要的应用前景，其中2-2.3微米波段在大气中有很高的透明度，主要应用在无线光通信和军事上，而2.3-3微米波段则被广泛应用在分子光谱及气体检测中。本项目中，为了对比研究，利用气源分子束外研究技术，在InP衬底和GaAs衬底上生长了有源区为5层的InAs量子点激光器，利用半导体制造工艺技术，采用化学湿法腐蚀的技术，制备了双沟道窄脊条量子点激光器，研究发现热效应对激光器的性能影响非常大。采用腔模移动的方法，我们获得了量子点激光器的热系数和结温。在获得相关量子点材料的生长条件下，我们展开了2-3微米InAsSb/InP量子点生长条件研究，发现由于Sb原子的极性强，容易在InP衬底表面迁徙，导致生长的材料呈现量子线，很难实现量子点。为了获得2-3微米的激光器，我们在GaSb衬底上生长了GaInAsSb/AlGaAsSb的量子阱激光器，理论上GaInAsSb与GaSb晶格匹配，对于所有的GaInAsSb合金都是直接带隙半导体材料，而且它的禁带宽度比GaSb材料的要小，通过调节In在GaInAsSb中的比重可以实现大范围的禁带宽度的调节。通过化学湿法腐蚀的制备工艺研究，制备出脊条宽度为10微米和腔长为1.5mm的激光器，该激光器实现室温连续波模式下工作，工作中心波长在2.039微米，器件单面最大输出功率超过了50mW。