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in creator/contributor: "Feldman, L. C."

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Measurement of x-rays emitted from projectiles moving in solid targets

The results of three separate experiments all dealing with the production of x-rays in projectiles moving in solids are discussed. The first experiment deals with the measurement of line widths of x-rays emitted from projectiles moving in solid targets. The effect of collisional broadening of x- rays is found to dominate the line widths giving greater than an order of magnitude increase in the measured line widths. The second experiment studies ''solid target effects'' in producing non-binomial… more

Date: January 1, 1975

Creator: Fortner, R. J.; Matthews, D. L.; Feldman, L. C.; Garcia, J. D. & Oona, H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Mesoscale Engineering of Nanocomposite Nonlinear Optical Materials

Complex nonlinear optical materials comprising elemental, compound or alloy quantum dots embedded in appropriate dielectric or semiconducting hosts may be suitable for deployment in photonic devices. Ion implantation, ion exchange followed by ion implantation, and pulsed laser deposition have ail been used to synthesize these materials. However, the correlation between the parameters of energetic-beam synthesis and the nonlinear optical properties is still very rudimentary when one starts to as… more

Date: November 1, 1999

Creator: Afonso, C.N.; Feldman, L.C.; Gonella, F.; Haglund, R.F.; Luepke, G.; Magruder, R.H. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Research Opportunities in Crystalline Silicon Photovoltaics for the 21st Century: Preprint

Crystalline silicon continues to be the dominant semiconductor material used for terrestrial photovoltaics. This paper discusses the scientific issues associated with silicon photovoltaics processing and cell design that may yield cell and module performance improvements, both evolutionary and revolutionary in nature. We first survey critical issues in ''thick'' crystalline silicon photovoltaics, including novel separations processes for impurity removal, impurity and defect fundamentals, inter… more

Date: April 1, 1999

Creator: Atwater, H. A. (California Institute of Technology); Sopori, B.; Ciszek, T. (National Renewable Energy Laboratory); Feldman, L. C. (Vanderbilt University); Gee, J. (Sandia National Laboratories) & Rohatgi, A. (Georgia Institute of Technology)

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

The Effects of Nitrogen on the Interface State Density Near the Conduction Band Edge in 4H and 6H-SiC

Results are reported for the passivation of interface states near the conduction band edge in SiO{sub 2}/SiC MOS capacitors using post-oxidation anneals in nitric oxide, ammonia and forming gas (N{sub 2}5%H{sub 2}). Anneals in nitric oxide and ammonia reduce the interface state density significantly for 4H-SiC, while forming gas anneals are largely ineffective. Results suggest that interface states in SiO{sub 2}/SiC and SiO{sub 2}/SiC have different origins, and a model is described for interfa… more

Date: June 12, 2000

Creator: Chung, G. Y.; Tin, C. C.; Isaacs-Smith, T.; Williams, J. R.; McDonald, K.; DiVentra, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nanostructured Arrays Formed by Finely Focused Ion Beams

Amorphous, polycrystalline, and single crystal nanometer dimension particles can be formed in a variety of substrates by ion implantation and subsequent annealing. Such composite colloidal materials exhibit unique optical properties that could be useful in optical devices, switches, and waveguides. However colloids formed by blanket implantation are not uniform in size due to the nonuniform density of the implant, resulting in diminution of the size dependent optical properties. The object of t… more

Date: November 30, 1998

Creator: Budai, J. D.; Datsos, P. G.; Feldman, L. C.; Heinig, K. H.; Meldrum, A.; Strobel, M. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Atomic-Scale Engineering of the SiC-SiO{sub 2} Interface

We report results from three distinct but related thrusts that aim to elucidate the atomic-scale structure and properties of the Sic-SiO{sub 2} interface. (a) First-principles theoretical calculations probe the global bonding arrangements and the local processes during oxidation; (b) Z-contrast atomic-resolution transmission electron microscopy and electron-energy-loss spectroscopy provide images and interface spectra, and (c) nuclear techniques and electrical measurements are used to profile N… more

Date: November 14, 1999

Creator: Buczko, R.; Chung, G.; Di Ventra, M.; Duscher, G.; Feldman, L. C.; Huang, M. B. et al.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Nanoscale Science, Engineering and Technology Research Directions

This report describes important future research directions in nanoscale science, engineering and technology. It was prepared in connection with an anticipated national research initiative on nanotechnology for the twenty-first century. The research directions described are not expected to be inclusive but illustrate the wide range of research opportunities and challenges that could be undertaken through the national laboratories and their major national scientific user facilities with the suppo… more

Date: January 1, 1999

Creator: Lowndes, D. H.; Alivisatos, A. P.; Alper, M.; Averback, R. S.; Jacob Barhen, J.; Eastman, J. A. et al.

Item Type: Report

Partner: UNT Libraries Government Documents Department