Interface Electronic Properties and Growth Parameters of Heterovalent Semiconductor Heterojunctions

9711851 Brillson该项目旨在促进对ZnSe/GaAs，GaAs/GeSi和GaN/Al 2 O3界面和生长过程的理解，重点是界面能带对准和深层次的控制。一个全面的计划，提出了优化异质结界面的电子性能，包括界面带的不连续性和化学稳定性对缺陷的形成和热降解。分子束外延生长，低能量阴极射线发光和光致发光光谱的掩埋界面，表面敏感的X射线和软X射线光电子能谱，和光学陷阱光谱的subsurfaces的组合将被用来优化生长过程，提高电气性能和化学稳定性。它有望将界面化学和电子特征与导致深能级和偶极子形成的原子运动联系起来。使用改变覆盖层，衬底化学计量，和外延夹层将进行光谱评估，以制定优化异质结界面性能的一般生长原则。该项目解决了具有高技术相关性的材料科学专题领域的基础研究问题。 该研究将在基础层面上为电子/光子器件的重要方面提供基础材料科学知识。 此外，从研究中获得的基本知识和理解有望通过提供设计和生产改进材料和材料组合的基本理解和基础，有助于提高先进器件和电路的性能和稳定性。 该计划的一个重要特点是通过在一个基本和技术上重要的领域对学生进行培训来整合研究和教育。***

9711851 Brillson This project seeks to advance understanding of ZnSe/GaAs, GaAs/GeSi, and GaN/Al2O3 interfaces and growth processes with emphasis on control of interface band alignment and deep levels. A comprehensive plan is presented for optimizing heterovalent heterojunction interface electronic properties, including both interfacial band discontinuities and chemical stability against defect formation and thermal degradation. The combination of molecular beam epitaxial growth, low energy cathodoluminescence and photoluminescence spectroscopies of buried interfaces, surface-sensitive x-ray and soft x-ray photoemission spectroscopies, and optical trap spectroscopies of subsurfaces will be employed to optimize growth processes for both improved electrical properties and chemical stability. It is expected to link interface chemical and electronic features with the atomic movements leading to deep level and dipole formation. Use of altered overlayer, substrate stoichiometries, and epitaxial interlayers will be assessed spectroscopically to develop general growth principles for optimizing heterojunction interface properties. %%% The project addresses basic research issues in a topical area of materials science having high technological relevance. The research will contribute basic materials science knowledge at a fundamental level to important aspects of electronic/photonic devices. Additionally, the fundamental knowledge and understanding gained from the research is expected to contribute to improving the performance and stability of advanced devices and circuits by providing a fundamental understanding and a basis for designing and producing improved materials, and materials combinations. An important feature of the program is the integration of research and education through the training of students in a fundamentally and technologically significant area. ***