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CREST Nanoscale Analytical Sciences Research and Education Center


 

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Dr. Clayton W. Bates, Jr.

 

Research Interests

Materials Science and Characterization, Solid-State and Device

Physics

Electronic Transport and Optical Properties of Crystalline and

Amorphous Solids

X-ray Photoelectron and Ultraviolet Photoelectron Spectroscopy of

Surfaces

Nanophase Metal-Semiconductor Composites

Infrared Detectors

 

Dr. Bates’s research interests have spanned a broad range in theoretical, solid-state and device physics that include x-ray image intensification, preparation and properties of thin films using sputtering and high vacuum depositions, Hall effect and optical measurements of metal-semiconductor nanophase composite systems. He was a pioneer in the use of insitu x-ray photoelectron spectroscopy (XPS) for the determination of complex photo-electronically active sufaces and performed the first XPS measurement on an amorphous material, lead silicate glass, that is used in making microchannel plates. Using this technique he determined for the first time the structure of the S-1 photocathode that has been in use since 1930. He and his students at Stanford University developed a theoretical technique for determining the optical behavior of metal-semiconductor composites, the Dynamic Effective Medium Approximation (DEMA), involving no adjustable parameters. It has been successful in character-izing the absorption, transmission and reflection of a number of these materials. Most recently his work has involved the study of Ag-Si composite systems for the detection of infrared radiation and in particular the earth’s three atmospheric windows, i.e. 1-2, 3-5 and 8-14µm wavelengths. He developed a formula for the room temperature quantum efficiency of metal-semiconductor composite systems involving only experimentally determined quantities. For his work in developing a state-of-the-art x-ray image intensifier tube for diagnostic radiology he received the Varian Sabbatical Year award (1968). He was awarded the title of “Distinguished Engineer” in 1979 by Tau Beta Pi, the national engineering honor society for his work on photocathodes. In 1982 he was elected a Fellow of the American Physical Society for his contributions to nonlinear statistical mechanics and the understanding of the structure and bonding of amorphous materials. In 2004 he was elected a History Maker of the 20th Century by the History Makers organization in Chicago, Ill. for outstanding research in electronic Materials research and for the education of African-American Scientists and Engineers.

 

Research and Professional Experiences

Howard University

1994 – present, Research Professor, Department of Electrical and Computer Engineering;

1995 – 2004, Associate Dean for Graduate Education and  Research, College of Engineering, Architecture and Computer Sciences.

 

Stanford University 1972-1994

1972 – 1976, Associate Professor, Departments of Materials Science and  Engineering and Electrical Engineering (joint appointment) School of Engineering

1976 – 1994, Professor, same departments.

At Stanford he taught graduate courses in Quantum Mechanics, Electromagnetic Theory, Photo-electronic Materials and Devices and a Solid-State Characterization Laboratory Course. In 1973 he organized and became the first faculty advisor for the Society of Black Scientists and Engineers (SBSE), a precursor of the National Society of Black Scientists and Engineers. He advised the research of 17 Ph.D. and 5 M.S. students

 

Publications since 1998

A. Rahman, W. P. Lowe and C. W. Bates, Jr., “The Use of Reliability Factors in Analyzing Powder Patterns in Pt-Si Sputtering Targets and Subsequent Films”, Jour. Mater. Res., 13 (6), 1517 (1998).

A. Rahman, C. W. Bates, Jr., A. F. Marshall, S. B. Qadri and T. Bari, “Microstructural and Electronic Transport Properties of PtxSi/p-Si(100) Metal-Semiconductor Composite Films”, Mater. Letts. 39, 343 (1999).

A. Rahman, C. W. Bates, Jr., W. P. Lowe and A. F. Marshall, “Transmission Electron Microscopy Study of PtSi/Si(p-type) Composites Grown on Si (111) Substrates”, Mater. Sci. and Eng. B77, 242 (2000).

A. Rahman and C. W. Bates, Jr., “Chemical Etch Studies of PtSi/p-Si(100) Metal-Semiconductor Composite Films”, Materials Letters 54, 98 (2002).

Ibrahima Diagne, Juan White, Mandoye Ndoye Clayton W. Bates, Jr. and W. Robert Thurber, “Chemical Etch Studies of Ag/n-Si Metal-Semiconductor Composite Films”, Materials Letters 59, 1640 (2005).

C.W. Bates, Jr. and A.J. Hendricks, “Quantum Efficiencies of PtSi/p-Si Composites in the 3-5µm Wavelength Range”, Appl. Phys. Letts. 87(23), 233510 (2005).

 

C.W. Bates, Jr., A.J. Hendricks, I.N. Bankman, M.E. Thomas and D.T. Prendergast, “Temperature Dependence of Noise Equivalent Temperature Change of PtSi/p-Si Composites in the 3-5µm Wavelength Range”, Appl. Phys. Letts. 88(9), 092109 (2006).

 

C. W. Bates, J.C. White and C. Ekeocha, “Transmission Electron Microscopy Study of Ag/n-Si Composites grown on Si (111) Substrates”, Materials Science and Engineering B 143, 38 (2007).

 

Christopher C. Perry, Chichang Zhang, Emanuel Waddell, Clayton W. Bates, Jr. and James W. Mitchell, “Chemical etching of Nanocomposite Films Monitored by Raman Spectroscopy and Surface Probe Microscopy” SPIE 6891, 689116 (2008).

 

C.W. Bates, Jr. and Chichang Zhang, “Electric Field Dependence of Quantum Efficiencies of Ag/n-Si Composites in the Infrared at Room Temperature”, Jour. of Appl. Phys. 104, 076101 (2008).

 

Chichang Zhang and C.W. Bates, Jr., “Metal-Mediated Crystallization in Si-Ag Systems”, Thin Solid Films 517,  5783 (2009).

 

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