25 Result(s)
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Article
Formation of BN and AlBN During Nitridation of Sapphire Using RF Plasma Sources
Evidence is presented that nitrogen plasma sources utilizing a pyrolytic boron nitride liner may be a significant source of B contamination during growth and processing. Auger electron spectroscopy analysis pe...
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Article
High-Temperature Illumination-Induced Metastability in Undoped Semi-Insulating GaN Grown by Metalorganic Vapor Phase Epitaxy
High-temperature (high-T) illumination-induced metastability in undoped semi-insulating (SI) GaN grown on a-plane sapphire by metalorganic vapor phase epitaxy has been studied using thermally stimulated curren...
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Article
Influence of Active Nitrogen Species on the Nitridation Rate of Sapphire
The operating regimes of two rf-plasma sources, an Oxford CARS-25 and an EPI Unibulb, have been extensively characterized. By changing the exit aperture configuration and using an electrostatic deflector, the ...
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Article
GaN Photonic Crystal-Based, Enhanced Fluorescence Biomolecule Detection System
The need for small form factor, portable biosensing platforms is prevalent across a wide range of medical, environmental, and defense applications. This paper presents the design of a novel, integrated optoflu...
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Article
Changes in Optical Properties of GaAsN During Annealing
GaAs1−xNx layers and quantum dot-like structures were grown on (100) GaAs substrates by molecular beam epitaxy. The dependence of photoluminescence emission spectra on annealing temperature is consistent with lit...
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Article
In-Situ Investigation of Surface Stoichiometry During InGaN and GaN Growth by Plasma-Assisted Molecular Beam Epitaxy Using RHEED-TRAXS
Reflection high-energy electron diffraction total-reflection-angle x-ray spectroscopy (RHEED-TRAXS) uses high-energy electrons from RHEED to excite x-ray fluorescence. Monitoring characteristic x-rays of selec...
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Article
The Use of Cathodoluminescence in Gallium Nitride During Growth to Determine Substrate Temperature
Cathodoluminescence measurements made during the growth of GaN films represent an alternate method of substrate temperature determination. The wavelength corresponding to a given growth temperature can be dete...
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Article
Compensation in Be-doped Gallium Nitride Grown Using Molecular Beam Epitaxy
Three techniques to improve beryllium do** in Ga-polar GaN grown by molecular beam epitaxy were investigated: growth under atomic hydrogen, growth under electron irradiation, and growth under an In flux. The...
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Article
Surface Potential Measurements of do** and defects in p-GaN
The interaction of Be-, Mg-, and Si- doped GaN epitaxial films with atomic hydrogen, produced by a remote r.f. hydrogen plasma, is investigated. The kinetics of the interaction is monitored in real time by spe...
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Article
Thermal Activation of Beryllium in GaN Grown by RF-Plasma Molecular Beam Epitaxy
Differences in the optical activity of Be in GaN epilayers grown on different surface polarities by rf-plasma molecular beam epitaxy are investigated. Nitrogen-polar GaN doped with Be exhibits a significantly ...
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Article
Raman Studies on Oxygen Doped GaN Grown by Molecular Beam Epitaxy
High quality Ga-polarity GaN films were grown by plasma-assisted molecular beam epitaxy to study strain effects due to oxygen incorporation. Oxygen concentrations up to 2 × 1022 cm−3 were studied. Layers containi...
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Article
A Comparison of Magnesium and Beryllium Acceptors in GaN Grown by rf-Plasma Assisted Molecular Beam Epitaxy
Step-doped structures of both magnesium and beryllium were grown in GaN and analyzed using secondary ion mass spectrometry. Dopant incorporation was studied as a function of substrate temperature and dopant fl...
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Article
Formation of BN and AlBN During Nitridation of Sapphire Using RF Plasma Sources
Evidence is presented that nitrogen plasma sources utilizing a pyrolytic boron nitride liner may be a significant source of B contamination during growth and processing. Auger electron spectroscopy analysis pe...
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Article
An Investigation of Long and Short Time-Constant Persistent Photoconductivity in Undoped GaN Grown By RF-Plasma Assisted Molecular Beam Epitaxy
Photoconductance decay and spectral photoconductance measurements were made on a set of ten undoped layers of GaN grown by rf-plasma MBE. The layers, also characterized by Hall, photoluminescence and reflectan...
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Article
Temperature Dependent Hall Measurements on CdGeAs2
Seventeen samples of CdGeAs2 have been extensively characterized by temperature-dependent Hall effect and resistivity measurements. Due to the anisotropic nature of the electrical properties, carefully matched sa...
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Article
Influence of Active Nitrogen Species on the Nitridation Rate of Sapphire
The operating regimes of two rf-plasma sources, an Oxford CARS-25 and an EPI Unibulb, have been extensively characterized. By changing the exit aperture configuration and using an electrostatic deflector, the ...
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Article
Hydrogenation of Undoped and Nitrogen Doped Cdte and ZnSe Grown by Molecular Beam Epitaxy
Hydrogen incorporation in both undoped and nitrogen-doped CdTe and ZnSe is investigated. Evidence for a strong nitrogen-hydrogen interaction is presented. Preliminary data indicate that the growth of CdTe and ...
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Article
The Effect of Hydrogen on the Molecular-Beam-Epitaxy Growth of GaN on Sapphire Under Ga-Rich Conditions
Nucleation and growth of GaN under Ga-rich conditions by molecular beam epitaxy using a nitrogen rf plasma source is shown to result in both a smoother GaN surface and a reduced inversion domain content. In ad...
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Article
The Role of Atomic Hydrogen for Substrate Cleaning for Growth of CdTe Buffer Layers at Reduced Temperatures on Silicon, CdTe, and HgCdTe
Atomic hydrogen is shown to be efficacious for cleaning CdTe and HgCdTe substrates for subsequent CdTe growth by molecular beam epitaxy. While single crystal ZnTe and CdTe growth was obtained on Si substrates ...
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Article
Photoluminescence and Electron Paramagnetic Resonance of Nitrogen-Doped Zinc Selenide Epilayers
Photoluminescence (PL) and electron paramagnetic resonance (EPR) studies were performed on a series of ZnSe samples grown by molecular beam epitaxy. The PL has been studied as a function of excitation waveleng...
