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Search Publications by: Albert Davydov (Fed)

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Displaying 301 - 325 of 343

High Degree of Crystalline Perfection in Spontaneously Grown GaN Nanowires

January 1, 2006
Author(s)
Kristine A. Bertness, Alexana Roshko, Albert Davydov, Igor Levin, Mark D. Vaudin, Joy Barker, John B. Schlager, Norman Sanford, Larry Robins
We have grown a variety of isolated GaN nanowires using gas-source molecular beam epitaxy (MBE) and characterized their structural and optical properties. The nanowires have demonstrated a number of promising materials characteristics, including low defect

Molecular Beam Epitaxial Growth of High-Quality GaN Nanocolumns

January 1, 2006
Author(s)
J E. Van Nostrand, K L. Averett, R Cortez, J Boecki, C E. Stutz, Norman Sanford, Albert Davydov, J D. Albrecht
Vertically oriented GaN nanocolumns (NCs) approximately 90+10 nm wide and 0.75 microns tall were grown byt plasma-assisted molecular beam epitaxy on Al_(2)O_(3)(0001) and Si(111). The dense packing of the NCs gives them the appearance of a continuous film

Spontaneously grown GaN and AlGaN nanowires

January 1, 2006
Author(s)
Kristine A. Bertness, Alexana Roshko, Norman A. Sanford, Joy Barker, Albert Davydov
We have identified crystal growth conditions in gas-source molecular beam epitaxy (MBE) that lead to spontaneous formation of GaN nanowires with high aspect ratio on Si (1 1 1) substrates. The nanowires were oriented along the GaN c-axis and normal to the

Growth habits and defects in ZnO nanowires grown on GaN/sapphire substrates

August 31, 2005
Author(s)
Igor Levin, Albert Davydov, Babak Nikoobakht, Norman Sanford, Pavel Mogilevsky
Growth habits and defects in epitaxial ZnO nanowires grown from Au catalyst on (00.1) GaN/sapphire substrate using the vapor-liquid-solid (VLS) technique were studied using electron microscopy and x-ray diffraction. The results revealed presence of both

Growth Habits and Defects in ZnO Nanowires Grown on GaN/Sapphire Substrates

August 31, 2005
Author(s)
Igor Levin, Albert Davydov, Babak Nikoobakht, Norman A. Sanford, Pavel Mogilevsky
Growth habits and defects in epitaxial ZnO nanowires grown from Au catalyst on (0001) GaN/sapphire substrate using Vapor-Liquid-Solid (VLS) technique were studied using electron microscopy and X-ray diffraction. The results revealed presence of both

Measurement of Second Order Susceptibilities of GaN and AlGaN

March 1, 2005
Author(s)
Norman Sanford, Albert Davydov, Denis V. Tsvetkov, Vladimir A. Dmitriev, Stacia Keller, Umesh Mishra, Steven P. DenBaars, S S. Park, J H. Han
Rotational Maker fringes, scaled with respect to χ 11 (2) of crystalline quartz, were used to determine the nonlinear optical coefficients χ 31 (2) and χ 33 (2) for samples of thin Al xGa 1-xN films and a bulk free-standing GaN platelet. The Al xGa 1-xN

Fabrication and Analysis of GaN Nanorods grown by MBE

January 1, 2005
Author(s)
Norman Sanford, Larry Robins, Matthew H. Gray, J E. Van Nostrand, C Stutz, R Cortez, Albert Davydov, Alexander J. Shapiro, Igor Levin, Alexana Roshko
GaN nanorods were grown on c-plane sapphire substrates under N-rich conditions by plasma-assisted molecular-beam epitaxy. Scanning electron microsopy revealed densely packed nanorods of hexagonal cross section with diameters ranging from roughly 40 to 100

Refractive index and birefringence of InGaN films grown by MOCVD

January 1, 2005
Author(s)
Norman Sanford, Anneli Munkholm, Mike A. Krames, Alexander J. Shapiro, Igor Levin, Albert Davydov, Safak Sayan, L Wielunski, T E. Madey
The refractive index and birefringence of InxGa1'xN films grown on GaN layers were measured by prism coupling used in conjunction with multilayer optical waveguide analysis. Samples with x = 0.036, 0.049, 0.060, and 0.066 were examined at the separate

Combinatorial Investigation of Structural Quality of Au/Ni Contacts on GaN

June 1, 2004
Author(s)
Albert Davydov, Leonid A. Bendersky, William J. Boettinger, Daniel Josell, Mark D. Vaudin, C S. Chang, Ichiro Takeuchi
A combinatorial library of Au/Ni metalizations on GaN were microstructurally characterized by x-ray diffraction (XRD), electron back-scattered diffraction (EBSD) and transmission electron microscopy (TEM). The array of single- and bi-layered metal elements

Structural, Electronic and Optical Properties of B-(Fe 1-x Co 2 )Si 2

March 11, 2004
Author(s)
D B. Migas, Leo Miglio, M Rebien, W Henrion, P Stauss, Anthony G. Birdwell, Albert Davydov, V L. Shaposhnikov, V E. Borisenko
Optimized crystal structure, electronic bands and density of states nearby the band gap, and the dielectric function of -(Fe1-xCox)Si2 with x equal to 0.0625 and 0.125 were obtained by means of total energy ultrasoft pseudopotential and full-potential

Controlling The Growth Direction of ZnO Nanowires (NWs) on c and a -Plane Sapphire

February 1, 2004
Author(s)
Babak Nikoobakht, Albert Davydov, Stephan J. Stranick
The issue of controlling the growth direction of NWs is vital in nanotechnology applications and future optoelectronic devices. In an effort to address the above, we have begun studies aimed at selectively controlling the growth direction of horizontal