UScholar Works
 
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CreatorTitleDescriptionSubjectDate
1 Stringfellow, Gerald B.Radiative pair transitions in p-type ZnSe:Cu crystalsShallow levels with an ionization energy of 0.012 eV play an important role in the photoelectronic properties of p-type ZnSe:Cu crystals. These levels exhibit the characteristics of the higher-lying member of an imperfection pair involved in luminescence emission, as well as of a trap determining lo...Ionization energy; Luminescence emission; Crystals1968
2 Stringfellow, Gerald B.Dislocations in GaAs17-xPxDislocations, their origins, and their effects on photoluminescence efficiency have been studied in GaAs1-xPx single crystals grown by vapor phase epitaxy. Dislocations were observed using etch pit, optical-transmission microscopy, and x-ray topography techniques. Two types of dislocations are grown...Photoluminescence efficiency; Growth mechanism; Optical transmission microscopy1969
3 Stringfellow, Gerald B.Electrical properties of nitrogen doped GaPThe electrical properties namely, electron concentration and mobility, have been investigated in the temperature range from 53 to 400 K for undoped and nitrogen-doped VPE GaP.Electron concentration; Ionization energy; Electron mobility1975
4 Stringfellow, Gerald B.Mechanism for liquid phase epitaxial growth of nonequilibrium compositions producing a coherent interfaceA model is presented for growth by so-called composition pulling, wherein an epitaxial deposit grows coherently but with a composition different from that which would be in bulk equilibrium with the liquid phase from which growth occurs. The breakdown of coherent growth occurs when a dislocation nuc...Lattice-matching overgrowths; Composition pulling; Dislocation interface1977
5 Stringfellow, Gerald B.Electron mobility in AlxGa1-xAshe electron mobility in AlxGa1-xAs grown by several techniques has been studied to determine whether VPE layers are more highly compensated than comparable LPE layers. The techniques used to grow layers included (1) organometallic VPE using Al(CH3)3, AsH3, and Ga(C2H5)3 or Ga(CH3)3, (2) ''hybrid'' o...Alloys; Organometallics1979-06
6 Stringfellow, Gerald B.Deep electron traps in organometallic vapor phase grown AlGaAsDeep electron traps have been studied by means of deep level transient spectrosocopy in type nominally undoped and interntionally te doped Al Ga As epitaxial layers which were grown by vapor phase epitaxy from organometallic compounds (OMVPE). Three main deep electron levels are present in undoped m...Vapor phase epitaxy; Shallow impurity identity; Optoelectronic device performance1980
7 Stringfellow, Gerald B.Photoluminescence of Shallow Acceptors in Epitaxial AlGaAsThe low-temperature (2 K) photoluminescence (PL) of AlxGa1-xAs (0<x<0.25 was studied in an effort to characterize shallow acceptors in material grown by organometallic vapor phase epitaxy and liquid phase epitaxy techniques. The dominant shallow acceptor in nominally undoped AlxGa1-xAs specimens gro...Photoluminescence; Acceptors; Doping1980
8 Stringfellow, Gerald B.Electron mobility in compensated GaAs and AlGaAsThe dependence of electron mobility on temperature in GaAs and Al Ga As indicates that for cimpensated material a term having causes a significant reduction in the mobility measured at high temperatures. The magnitude of the term in mobility, denoted is found to be linearly proportional to the compe...Unspecified mobility; Reduced mobility; Space charge regions1980
9 Stringfellow, Gerald B.Miscibility gaps and spinodal decomposition in III/V quaternary alloys of the type AxByC1−x−yDThermodynamic concepts have been developed for the calculation of solid-phase miscibility gaps and spinodal decomposition in quaternary alloys of the type AxByC1−x−yD. These concepts have been applied to the analysis of III/V quaternary alloys using the delta-lattice-parameter (DLP) solution mod...Thermodynamics; Quartenary alloys; Coherent decomposition1983-01
10 Stringfellow, Gerald B.; Cohen, Richard M.Organometallic vapor phase epitaxial growth of high purity GaInAs using trimethylindiumGax In1−xAs lattice matched to the InP substrate (x=0.47) has been grown by organometallic vapor phase epitaxy using trimethylindium (TMIn) and trimethylgallium (TMGa) as the group III sources and AsH3 as the As source. In a simple, horizontal, atmospheric pressure reactor, the GaInAs growth proce...Electron mobilities; Photouminescience; Fabricate modulation1984-03-01
11 Stringfellow, Gerald B.Organometallic vapor phase epitaxial growth of AlGaInPAlx Ga,, In, _ x _ y P with x + y = 0.51, lattice matched to the GaAs substrate, has been grown by organometaUic vapor phase epitaxy. The simple, horizontal, IR heated system operates at atmospheric pressure using the reactants TMA1, TMGa, TMln, PH3, and K2. Alloys giving room temperature, band edge...Liquid phase epitaxial growth; LPE; Alloys; Surface morphology1985
12 Stringfellow, Gerald B.GaInAsSb metastable alloys grown by organometallic vapor phase epitaxyGa1-xlnx As1-ySby alloys have been grown by organometallic vapor phase epitaxy using trimethyl compounds of Ga, In, As, and Sb(TMGa, TMIn, TMAs, and TMSb) plus AsH3 in an atmospheric pressure, horizontal, infrared heated reactor. For the first time, alloys near the center of the region of solid immi...Organometallic; Alloys; Vapor phase epitaxy1986
13 Stringfellow, Gerald B.Doping studies of Ga0.5In0.5P organometallic vapor-phase epitaxyPresents doping studies of gallium[sub0.5] indium[sub0.5] phosphorus organometallic vapor-phase epitaxy. Distribution coefficient of indium; Description of growth conditions; Case of poor growth morphology for gallium[sub0.5] indium[sub0.5] phosphorus.Phosphorus; Gallium; Doping1986
14 Liu, FengStability of doubly charged transition-metal dimersThe spatial dependence of the interaction potentials in doubly charged dimers of transition-metal atoms has been calculated by use of both the tight-binding and the self-consistent-field linear combination of atomic orbitals-molecular orbitals methods. The study reveals an interesting correlation be...Doubly charged; Transition metal dimers; Spatial dependence; Interaction potentials; Metastability1987-11
15 Liu, FengSimple theory of the electronic structure: clusters to crystalsA simple scheme based upon a cross between the molecular clusters and the tight-binding theory has been developed to calculate the electronic structure of a large class of systems ranging from molecules to solids. The method is applied to study the variations in the magnetic moments of Fe and Ni for...Clusters; Tight-binding theory; Magnetic moment1988-09
16 Liu, FengMagnetism and local order: ab initio tight-binding theoryThe effects of the local environment on the electronic structure and magnetic moments of Fe, Co, and Ni have been studied by confining these atoms to assume various structural forms such as chains, surfaces, layers, and crystals. The coordination number of the atoms can thus be changed over a wide r...Local order; Ab-initio tight-binding theory; Magnetic moment; Electronic structure; Fe; Co; Ni1989-04
17 Liu, FengMagnetism and local order II: self-consistent cluster calculationsThe effect of the local environment on the magnetic moment and its convergence to bulk value has been studied self-consistently by using a molecular-cluster model within the framework of spin-density-functional theory. We show that the magnetic moment of the central atom in clusters of 43 Ni atoms a...Local order; Magnetic moment; Molecular-cluster model; Spin-density-functional theory1989-07
18 Liu, FengTheory of hydrogen pairing in yttriumThe energetics of hydrogen atoms interacting with yttrium have been investigated using the self-consistent cluster model and the local-density approximation. Our results provide a theoretical understanding of a range of novel phenomena observed recently in resistivity, neutron scattering, NMR, and ...Hydrogen pairing; Self-consistent cluster model; Local-density approximation; Energetics1989-09
19 Liu, FengLiu et al. replyIn our paper we were alluding to a structural phase transition rather than an order-disorder one. We agree with Blaschko2 that more work needs to be done regarding the statistical mechanics of the hydrogen ordering. This was already acknowledged in our paper when we stated that the model of nonint...Structural phase transition; Hydrogen ordering; Ising lattice-gas models; Proton glass1990
20 Liu, FengEffect of size and dimensionality on the magnetic moment of transition metalsThe effect of size and dimensionality on the magnetic moments of Fe, Co, and Ni have been studied theoretically by confining the atoms t o various structural forms such as chains,surfaces, and thin films. The size of these systems is controlled by limiting t h e number of atoms. A new first-princip...Magnetic moment; Dimensionality; Size effects; Fe; Co; Ni1990
21 Liu, FengQuantum size effect on the magnetism of finite systemsThe magnetic moments of the ferromagnetic transition metals Fe, Co, and Ni confined to one-dimensional chains are found to fluctuate with increasing chain length before converging to the infinite limit. This quantum size effect is derived from a simple first-principles theory that we have developed...Quantum size; Finite systems; Ferromagnetic transition metals; Magnetic moments; Fe; Co; Ni; Molecular-orbital approach1990-07
22 Liu, FengMagnetism in small vanadium clustersUsing the self-consistent-field molecular-orbital theory and the density-functional approximation, we show that vanadium could become magnetic if its size and dimension were constrained. This is illustrated for vanadium forming clusters with body-centered-cubic (bcc) geometry as well as for linear c...Vanadium clusters; Molecular-orbital theory; Density-functional approximation; Stoner criterion1991-04
23 Stringfellow, Gerald B.Long wavelength lattice dynamics for quaternary alloys: GaInPSb and AlGaAsSbPresents information on a study which investigated the long wavelength lattice dynamics of quaternary alloys. Theory of the random cell isodisplacement model; Secular equation developed; Results and discussion.Lattice dynamics; Quaternary alloys1992
24 Stringfellow, Gerald B.Effect of oxygen incorporation in semi-insulating (AlxGa1-x)yIn1-yPDiscusses a study conducted on oxygen-doped, semi-insulating layers of (aluminum-gallium) indium phosphide grown on gallium arsenide using organometallic vapor phase epitaxy. Effect of oxygen doping on semi-insulating layers of the substance; Secondary-ion mass spectrometry measurements; Measured co...Inactive interstitial atoms; Energy-dispersive spectoscopy; intentional oxygen1992
25 Stringfellow, Gerald B.Tertiarybutyldimethylantimony: a new Sb source for low temperature organometallic vapor phase epitaxial growth of InSbThis article investigates tertiarybutyldimethylantimony as a source for low-temperature organometallic vapor phase epitaxial growth of indium antimonide (InSB); extraction of good surface morphology InSb layers; efficiency of InSB growth; and, presence of a negligible parasitic reaction between trim...Tertiarybutyldimethylantimony; Indium antimonide crystals1992
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