GOALI: Defect Formation and Phase Transitions in 2-5 Micron GaInAsSb Semiconductor Quaternary Alloys versus Ga(In)Sb/InAs Short Period Superlattices

技术：该项目研究锑III-V材料的相变和缺陷形成，包括直接间隙季系材料GaInAsSb和InAs/Ga(in)Sb超晶格，其带隙覆盖2-5微米光谱范围。这些材料对于红外光电器件，包括光电二极管探测器、发光二极管、激光二极管和热光电器件，预计将变得越来越重要。然而，根据热力学计算，在热力学平衡条件下生长的GaInAsSb合金在GaSb衬底上没有应变，在合金相空间中存在不混溶区，这可能限制了所需成分的稳定性。该项目将研究和绘制应变和生长动力学对量子阱GaInAsSb合金在热力学不混相区域的影响。成像技术将用于研究特征缺陷的形成，相分离和spinodal分解。光致发光、吸收和光学寿命测量将用于关联形貌和光学性质，包括辐射和非辐射衰变过程。GaInAsSb合金的替代材料，具有覆盖2-5微米波长区域的直接间隙，短周期，ii型InAs/Ga(In)Sb超晶格（T2SL）。它们与GaInAsSb合金有几个共同的特征，包括共同的元素组成，以及由于混合而在界面和层内形成的GaInAsSb区域。该项目旨在推进对GaInAsSb合金和InAs/Ga(In)Sb超晶格晶体生长和材料特性的最新理解，并允许在uia的研究级MBE反应器以及IQE的工业级MBE反应器中进行测试。通过ASL Analytical提供的理论计算，对这些材料的测量和计算性能进行比较，将获得新的、全面的数据。非技术：该GOALI（与工业界联系的资助机会）项目解决材料科学主题领域的基础研究问题，具有高技术相关性。爱荷华大学学术小组与工业合作伙伴之间的合作关系，IQE和ASL分析是协同的，并为科学，技术和教育影响提供了有利的机会。PI将招募和雇用一名新的研究生和本科生参与该项目，并在研究生完成博士学位期间为其提供建议。研究生将获得在学术（uia）和工业（IQE， ASL）环境中工作的研究经验。PI将重新启动一个名为“科学家庭冒险”的美国大学物理和天文学推广项目，由不同的教师就一个主题向公众举办一系列讲座；其中一个主题是半导体。此外，PI将为一年级学生提供一个学分的研讨会，通过研究几位著名科学家来研究科学方法。

Technical: This project addresses phase transitions and defect formation in antimonide III-V materials, including direct gap quaternary materials GaInAsSb and InAs/Ga(In)Sb superlattices having bandgaps covering the 2-5 micron spectral range. These materials are expected to be of growing importance to infrared optoelectronic devices, including photodiode detectors, light emitting diodes, laser diodes, and thermophotovoltaics. However, GaInAsSb alloys grown under thermodynamic equilibrium conditions unstrained on GaSb substrates have immiscibility regions in the alloy phase space according to thermodynamic calculations, potentially limiting stability of desired compositions. This project will study and map out the influence of strain and growth kinetics on quantum well GaInAsSb alloys across the thermodynamic immiscibility region. Imaging techniques will be used to study characteristic defect formation, phase separation, and spinodal decomposition. Photoluminescence, absorption and optical lifetime measurements will be used to correlate morphology and optical properties, including radiative and nonradiative decay processes. Alternative materials to GaInAsSb alloys with direct gaps covering the 2-5 micron wavelength region, short-period, type-II InAs/Ga(In)Sb superlattices (T2SL) will be addressed as well. They have several characteristics in common with GaInAsSb alloys, including common elemental composition, as well as GaInAsSb regions at interfaces and in layers due to intermixing. The project aims to advance state-of-the-art understanding of crystal growth and material properties of GaInAsSb alloys and InAs/Ga(In)Sb superlattices, and allows testing at both research grade MBE reactors at U. IA as well as industrial grade MBE reactors at IQE. New, comprehensive data will be obtained on comparisons between measured and calculated properties of these materials, with theoretical calculations provided by ASL Analytical. Non-technical: This GOALI (Grant Opportunities for Liaison with Industry) project addresses basic research issues in a topical area of materials science with high technological relevance. Collaborative links between the University of Iowa academic group and industrial partners, IQE and ASL Analytical are synergistic, and provide advantageous opportunities for scientific, technological, and educational impacts. The PI will recruit and hire a new graduate and undergraduate student to work on the project and advise the graduate student through the completion of his or her PhD. The graduate student will get research experience working both in academic (U. IA) and industrial (IQE, ASL) environments. The PI will reinvigorate a U. IA Physics and Astronomy outreach program called "Family Adventures in Science," featuring a series of lectures on a theme by different faculty members to the public; one of the themes will be semiconductors. Additionally, the PI will propose a one credit seminar for first year students on approaches to science through study of several famous scientists.