Fundamental Properties of GaAsN and InGaAsN - Toward Optoelectronic Applications

GaAsN 和 InGaAsN 的基本特性 - 面向光电应用

• 批准号: 0070240
• 负责人: Mark Holtz
• 金额: $ 24万
• 依托单位: Texas Tech University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-06-01 至 2004-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0070240&HistoricalAwards=false
• 关键词: Fundamental; Properties; GaAsN; InGaAsN; Toward

It is proposed to grow and characterize ternary alloys of conventional III-Vcompounds (e.g. GaAs, InAs) with III-N compounds (e.g. GaN, InN) on GaAssubstrates. These alloys are expected to be cubic with the zincblende structure and topossess a direct bandgap. However, the large lattice mismatch between GaAs and GaNand the difference in atomic orbital energies between As and N result in a very unusualcompositional dependence of the bandgap. The optical bowing coefficients in GaAs1-xNxare at least an order of magnitude greater than those encountered in common III-Valloys. Its bandgap decreases rapidly with increasing N fraction. This offers a possibilityof preparing novel optoelectronic devices, on GaAs substrates, operating in the 1.3 - 1.55mm range. The materials needed for this study will be grown by Metalorganic MolecularBeam Epitaxy (MOMBE). The effect of nitrogen incorporation on physicalmicrostructure and optical bandgap of epitaxial layers will be determined by a variety ofexperimental techniques. Raman scattering will be used to investigate microstructuraleffects such as nitrogen incorporation, spontaneous ordering, and phase separation.Raman results will be modeled using bond polarizability, a two-component molecularmodel, finite size, and strain effects. Near band edge optical properties will be studiedextensively by cw and time-resolved photoluminescence. These will focus on hownitrogen incorporation modifies carrier recombination. Ellipsometry and reflectancemethods will be used to gain information of the above-bandgap optical properties.Phenomenological deformation potentials model will be used to account for strain effectsin quantum wells and superlattices of InGaAsN/GaAs. Finally, quantum well structuresbased on InGaAsN/GaAs will be used as active layers to make vertical cavity lasersoperating in the wavelength range of 1.3-1.55 mm.

提出了在GaAs衬底上生长和表征常规III-V化合物（例如GaAs、InAs）与III-N化合物（例如GaN、InN）的三元合金。这些合金被认为是立方晶系的锌尖晶石结构，并具有直接的带隙。然而，GaAs和GaN之间的大的晶格失配和As和N之间的原子轨道能量的差异导致带隙的非常不寻常的组成依赖性。GaAs 1-xNx中的光学弯曲系数比常见的III-V合金中遇到的光学弯曲系数大至少一个数量级。其带隙随着N分数的增加而迅速减小。这为在GaAs衬底上制备工作在1.3 - 1.55mm范围内的新型光电器件提供了可能性。本研究所需的材料将通过金属有机分子束外延（MOMBE）生长。氮掺入对外延层的物理微结构和光学带隙的影响将通过各种实验技术来确定。拉曼散射将被用来研究微观结构效应，如氮的掺入，自发有序和相分离。拉曼结果将使用键极化率，双组分分子模型，有限尺寸和应变效应建模。连续波和时间分辨光致发光将对近带边光学性质进行深入研究。这些将集中在如何氮掺入修改载体重组。利用椭圆偏振法和反射法获得了InGaAsN/GaAs带隙以上的光学特性信息，采用唯象形变势模型对应变效应的量子威尔斯阱和超晶格进行了计算。最后，采用InGaAsN/GaAs量子阱结构作为有源层，使垂直腔激光器工作在1.3- 1.55mm波长范围内。