US-France Cooperative Research: Electronic and Opto- electronic Properties of 3-5 Compound

该奖项将支持佐治亚理工学院的Richard J.Higgins博士和他的研究小组与法国图卢兹国家应用科学研究所的J.C.Portal.博士的合作研究。希金斯和波特博士将研究3-5种化合物半导体异质结的电子和光电性质。这项研究将强调相干(量子)电子效应，并确定抑制量子电子器件的生长和加工问题。将研究两个测试系统：(A)分子束外延生长的耦合量子阱结构，其负微分电阻有望实现亚皮秒级的开关，但由于对物理行为的了解不足，其应用受到阻碍；(B)通过电子束光刻形成的纳米级结构可以显示出相相干弹道传输。美国和法国的调查人员在异质结构磁传输方面有共同的研究目标，并积极合作。技术包括探测电子行为的磁传输，改变缺陷电荷状态的脉冲光，以及改变能级的压力。希金斯博士的团队带来了傅里叶变换朗道能级光谱学的优势。这家法国集团在异质结构的磁输运和高压测量方面拥有专业知识，这对异质结构研究很有价值。本研究的成果将：1)加深对半导体量子阱异质结构和量子尺寸效应器件的了解；2)为固体电子学的技术基础做出贡献。

This award will support cooperative research between Dr. Richard J. Higgins and his research group at Georgia Institute of Technology and Dr. J. C. Portal, Laboratoire de Physique des Solides, Institut National des Sciences Appliquees, Toulouse, France. Drs. Higgins and Portal will study the electronic and optoelectronic properties of 3-5 compound semiconductor heterostructures. The research will emphasize coherent (quantum) electronic effects, and identify growth and processing issues that inhibit quantum electronic devices. Two test systems will be studied: (a) coupled quantum well structures grown by molecular beam epitaxy, whose negative differential resistance promises sub-picosecond switching, but whose application is hampered by poor understanding of the physical behavior and (b) nanometer-scale structures patterned by e-beam lithography which can exhibit phase-coherent ballistic transport. Both the U.S. and French investigators have an active collaboration with shared research objectives in heterostructure magnetotransport. Techniques include magnetotransport to probe electronic behavior, pulsed light to alter defect charge state, and pressure to shift energy levels. Dr. Higgins' group brings strengths in Fourier Transform Landau Level spectroscopy. The French group has expertise in magnetotransport in heterostructures and also in high pressure measurements, valuable for heterostructure studies. The results of this research will: 1) increase understanding of semiconductor quantum-well heterostructure and quantum-size effect devices; and 2) contribute to the technology base of solid state electronics.