Search Results - (Author, Cooperation:K. W. Kim)
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1Latest Papers from Table of Contents or Articles in PressMin-Cheol Lee, Choong H. Kim, Inho Kwak, J. Kim, S. Yoon, Byung Cheol Park, Bumjoo Lee, F. Nakamura, C. Sow, Y. Maeno, T. W. Noh, and K. W. Kim
American Physical Society (APS)
Published 2018Staff ViewPublication Date: 2018-10-18Publisher: American Physical Society (APS)Print ISSN: 1098-0121Electronic ISSN: 1095-3795Topics: PhysicsKeywords: Electronic structure and strongly correlated systemsPublished by: -
2Latest Papers from Table of Contents or Articles in PressG. Zhang ; C. Li ; Q. Li ; B. Li ; D. M. Larkin ; C. Lee ; J. F. Storz ; A. Antunes ; M. J. Greenwold ; R. W. Meredith ; A. Odeen ; J. Cui ; Q. Zhou ; L. Xu ; H. Pan ; Z. Wang ; L. Jin ; P. Zhang ; H. Hu ; W. Yang ; J. Hu ; J. Xiao ; Z. Yang ; Y. Liu ; Q. Xie ; H. Yu ; J. Lian ; P. Wen ; F. Zhang ; H. Li ; Y. Zeng ; Z. Xiong ; S. Liu ; L. Zhou ; Z. Huang ; N. An ; J. Wang ; Q. Zheng ; Y. Xiong ; G. Wang ; B. Wang ; Y. Fan ; R. R. da Fonseca ; A. Alfaro-Nunez ; M. Schubert ; L. Orlando ; T. Mourier ; J. T. Howard ; G. Ganapathy ; A. Pfenning ; O. Whitney ; M. V. Rivas ; E. Hara ; J. Smith ; M. Farre ; J. Narayan ; G. Slavov ; M. N. Romanov ; R. Borges ; J. P. Machado ; I. Khan ; M. S. Springer ; J. Gatesy ; F. G. Hoffmann ; J. C. Opazo ; O. Hastad ; R. H. Sawyer ; H. Kim ; K. W. Kim ; H. J. Kim ; S. Cho ; N. Li ; Y. Huang ; M. W. Bruford ; X. Zhan ; A. Dixon ; M. F. Bertelsen ; E. Derryberry ; W. Warren ; R. K. Wilson ; S. Li ; D. A. Ray ; R. E. Green ; S. J. O'Brien ; D. Griffin ; W. E. Johnson ; D. Haussler ; O. A. Ryder ; E. Willerslev ; G. R. Graves ; P. Alstrom ; J. Fjeldsa ; D. P. Mindell ; S. V. Edwards ; E. L. Braun ; C. Rahbek ; D. W. Burt ; P. Houde ; Y. Zhang ; H. Yang ; E. D. Jarvis ; M. T. Gilbert
American Association for the Advancement of Science (AAAS)
Published 2014Staff ViewPublication Date: 2014-12-17Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Adaptation, Physiological ; Animals ; Biodiversity ; *Biological Evolution ; Birds/classification/*genetics/physiology ; Conserved Sequence ; Diet ; *Evolution, Molecular ; Female ; Flight, Animal ; Genes ; Genetic Variation ; *Genome ; Genomics ; Male ; Molecular Sequence Annotation ; Phylogeny ; Reproduction/genetics ; Selection, Genetic ; Sequence Analysis, DNA ; Synteny ; Vision, Ocular/genetics ; Vocalization, AnimalPublished by: -
3Latest Papers from Table of Contents or Articles in PressM. A. Groenen ; A. L. Archibald ; H. Uenishi ; C. K. Tuggle ; Y. Takeuchi ; M. F. Rothschild ; C. Rogel-Gaillard ; C. Park ; D. Milan ; H. J. Megens ; S. Li ; D. M. Larkin ; H. Kim ; L. A. Frantz ; M. Caccamo ; H. Ahn ; B. L. Aken ; A. Anselmo ; C. Anthon ; L. Auvil ; B. Badaoui ; C. W. Beattie ; C. Bendixen ; D. Berman ; F. Blecha ; J. Blomberg ; L. Bolund ; M. Bosse ; S. Botti ; Z. Bujie ; M. Bystrom ; B. Capitanu ; D. Carvalho-Silva ; P. Chardon ; C. Chen ; R. Cheng ; S. H. Choi ; W. Chow ; R. C. Clark ; C. Clee ; R. P. Crooijmans ; H. D. Dawson ; P. Dehais ; F. De Sapio ; B. Dibbits ; N. Drou ; Z. Q. Du ; K. Eversole ; J. Fadista ; S. Fairley ; T. Faraut ; G. J. Faulkner ; K. E. Fowler ; M. Fredholm ; E. Fritz ; J. G. Gilbert ; E. Giuffra ; J. Gorodkin ; D. K. Griffin ; J. L. Harrow ; A. Hayward ; K. Howe ; Z. L. Hu ; S. J. Humphray ; T. Hunt ; H. Hornshoj ; J. T. Jeon ; P. Jern ; M. Jones ; J. Jurka ; H. Kanamori ; R. Kapetanovic ; J. Kim ; J. H. Kim ; K. W. Kim ; T. H. Kim ; G. Larson ; K. Lee ; K. T. Lee ; R. Leggett ; H. A. Lewin ; Y. Li ; W. Liu ; J. E. Loveland ; Y. Lu ; J. K. Lunney ; J. Ma ; O. Madsen ; K. Mann ; L. Matthews ; S. McLaren ; T. Morozumi ; M. P. Murtaugh ; J. Narayan ; D. T. Nguyen ; P. Ni ; S. J. Oh ; S. Onteru ; F. Panitz ; E. W. Park ; H. S. Park ; G. Pascal ; Y. Paudel ; M. Perez-Enciso ; R. Ramirez-Gonzalez ; J. M. Reecy ; S. Rodriguez-Zas ; G. A. Rohrer ; L. Rund ; Y. Sang ; K. Schachtschneider ; J. G. Schraiber ; J. Schwartz ; L. Scobie ; C. Scott ; S. Searle ; B. Servin ; B. R. Southey ; G. Sperber ; P. Stadler ; J. V. Sweedler ; H. Tafer ; B. Thomsen ; R. Wali ; J. Wang ; S. White ; X. Xu ; M. Yerle ; G. Zhang ; J. Zhang ; S. Zhao ; J. Rogers ; C. Churcher ; L. B. Schook
Nature Publishing Group (NPG)
Published 2012Staff ViewPublication Date: 2012-11-16Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Animals ; Demography ; Genome/*genetics ; Models, Animal ; Molecular Sequence Data ; *Phylogeny ; Population Dynamics ; Sus scrofa/*classification/*geneticsPublished by: -
4Latest Papers from Table of Contents or Articles in PressZhang, J., Wu, T., Simon, J., Takada, M., Saito, R., Fan, C., Liu, X.-D., Jonasch, E., Xie, L., Chen, X., Yao, X., Teh, B. T., Tan, P., Zheng, X., Li, M., Lawrence, C., Fan, J., Geng, J., Liu, X., Hu, L., Wang, J., Liao, C., Hong, K., Zurlo, G., Parker, J. S., Auman, J. T., Perou, C. M., Rathmell, W. K., Kim, W. Y., Kirschner, M. W., Kaelin, W. G., Baldwin, A. S., Zhang, Q.
American Association for the Advancement of Science (AAAS)
Published 2018Staff ViewPublication Date: 2018-07-20Publisher: American Association for the Advancement of Science (AAAS)Print ISSN: 0036-8075Electronic ISSN: 1095-9203Topics: BiologyChemistry and PharmacologyGeosciencesComputer ScienceMedicineNatural Sciences in GeneralPhysicsKeywords: Cell Biology, Medicine, DiseasesPublished by: -
5Articles: DFG German National LicensesWoolard, D. L. ; Tian, H. ; Littlejohn, M. A. ; Kim, K. W. ; Trew, R. J. ; Ieong, M. K. ; Tang, T. W.
[S.l.] : American Institute of Physics (AIP)
Published 1993Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: A critical step in the development of all hydrodynamic transport models (HTMs), derived from moments of the Boltzmann transport equation, is the introduction of accurate closure relations to terminate the resulting infinite set of macroscopic equations. In general, there are a number of resulting integral terms that are highly dependent on the form of the true electron distribution function. The so-called heat flux term is one very important higher-moment term that requires attention. Methods for the accurate construction of an improved heat-flux model are presented. In this construction, a higher-moments approach is combined with a unique definition of electron temperature (i.e., based upon an ansatz distribution) to investigate the effects of conduction-band nonparabolicity and distributional asymmetry. The Monte Carlo method has been used to evaluate the resulting model closures and to study microscopic electron dynamics. These investigations have identified an important relationship between a particular symmetric (i.e., thermal) component of the electron distribution function and the heat flow vector. This knowledge is important because all the parameters in the HTM must be closed (i.e., related to each other through a common set of system variables) before the technique can be accurately applied to the study of electron transport in semiconductor devices.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesTian, H. ; Kim, K. W. ; Littlejohn, M. A.
[S.l.] : American Institute of Physics (AIP)
Published 1991Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: We present results from a theoretical study of the influence of doping profile variations on the performance of delta-doped AlGaAs/GaAs high electron mobility transistors (HEMTs). An ensemble Monte Carlo simulation coupled with a self-consistent solution of the two-dimensional Poisson equation is used to investigate HEMTs which employ both single and double delta-doped profiles with varying doping configurations. The calculated results reveal that single delta-doped HEMTs designed with identical threshold voltages exhibit improved device behavior when thinner delta-doped layers with more heavily doped concentrations are utilized. For double delta-doped HEMTs with an identical total doping in the AlGaAs layer, improved threshold voltage control is obtained as the spacing between two delta-doped layers increases. However, this increase in spacing also causes a degradation in transconductance, cut-off frequency, and switching time. As gate bias increases, the dependence of device performance (or degradation) on the spacing between doping planes becomes less pronounced due to the upward shift in threshold or "onset'' of parallel conduction in the AlGaAs layer.Type of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesKim, K. W. ; Stroscio, M. A. ; Bhatt, A. ; Mickevicius, R. ; Mitin, V. V.
[S.l.] : American Institute of Physics (AIP)
Published 1991Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: One-dimensional electron-optical-phonon interaction Hamiltonians in a rectangular quantum wire consisting of diatomic polar semiconductors are derived under the macroscopic dielectric continuum model. The scattering rates calculated in a GaAs square quantum wire show that when the quantum wire is free-standing in vacuum, the interaction by the surface-optical phonon modes is very strong and may dominate over other scattering processes, especially with dimensions of about 100 A(ring) or less. When the wire is embedded in a polar semiconductor (AlAs to be specific), the scattering rates by the surface-optical phonon modes become generally smaller, but yet comparable to those by the confined longitudinal-optical modes as the wire dimension shrinks. A considerable decrease in the total scattering rate for optical phonons as a result of simple reduction in dimensionality is not observed in this study.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesBhatt, A. R. ; Kim, K. W. ; Stroscio, M. A. ; Iafrate, G. J. ; Dutta, Mitra ; Grubin, Harold L. ; Haque, Reza ; Zhu, X. T.
[S.l.] : American Institute of Physics (AIP)
Published 1993Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Based on a simplified analysis of perfectly conducting metals, it has been suggested qualitatively that establishing metal-semiconductor interfaces at the heterojunctions of polar semiconductor quantum wells introduces a set of boundary conditions that dramatically reduces or eliminates unwanted carrier energy loss caused by interactions with interface longitudinal-optical (LO) phonon modes. In this article, it is theoretically demonstrated that comparable reductions in LO phonon scattering strengths may be achieved for metal-semiconductor structures with metal having realistic conductivities and Thomas–Fermi screening lengths.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesTian, H. ; Kim, K. W. ; Littlejohn, M. A.
[S.l.] : American Institute of Physics (AIP)
Published 1991Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The roles of DX centers and surface states associated with the n-AlGaAs layer of δ-doped AlGaAs/GaAs high-electron-mobility transistors have been investigated by employing a two-dimensional, self-consistent ensemble Monte Carlo simulation. It is found that both DX centers and surface states degrade device performance, particularly as gate-to-source voltage increases. This degradation is manifested largely through reduced channel electron concentration, increased intervalley scattering, and enhanced real-space transfer. Of the two defect states, DX centers have more detrimental influence on drain current and transconductance.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesKaneto, T. ; Kim, K. W. ; Littlejohn, M. A.
[S.l.] : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The dielectric response functions in the valence bands and in the conduction band of heavily doped zincblende semiconductors have been evaluated using the self-consistent field method and incorporating the finite lifetime of particles in the relaxation time approximation. Scattering rates of injected electrons are calculated with the Born approximation in the dielectric response function formalism at finite temperature. The finite particle lifetime introduces significant modifications to the spectral density function {Im[−1/ε(q,ω)]} at small q, where collective excitations (i.e., coupled phonon-plasmon modes) are heavily damped due to collisions. However, these modifications are small at large q. At the same time, the scattering rates of injected electrons are strongly affected by the temperature dependence of these effects, which are particularly significant for p-type semiconductors.Type of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesTian, H. ; Kim, K. W. ; Littlejohn, M. A. ; Mishra, U. K. ; Hashemi, M.
[S.l.] : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: Electron transport properties in GaAs n+-n-n+ structures with varying doping profiles (in the direction of electron transport) are investigated using self-consistent ensemble Monte Carlo simulations. In particular, we study the effects of ramp doping [i.e., linearly increasing (ramp-up) or decreasing (ramp-down) doping density within the n region] and spike doping (i.e., introducing one or more n+ spikes in the n region) on electron transport to assess differences, advantages, and potential applications of these doping profiles on device performance. Underlying physical mechanisms for electron transport in these structures are analyzed. Simulation results reveal that overall electron transport can be improved significantly by employing ramp-up (rather than ramp-down) doping and multispike (instead of single-spike) doping schemes. Potential advantages of variable doping in field-effect transistor applications include enhanced current drive capability, reduced source resistance, and improved breakdown characteristics.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: The macroscopic dielectric continuum model is used to derive electron-optical-phonon interaction Hamiltonians for binary/ternary heterostructures containing both single and double heterointerfaces. The formulation presented in this work leads to a general prescription for the calculation of mode-strength coefficients in ternary-containing heterostructures. An illustration of these results is provided by exhibiting the mode strengths of the interaction Hamiltonians for the interface and the half-space longitudinal optical modes in a GaAs/AlyGa1−yAs single heterostructure.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesKim, K. W. ; Bhatt, A. R. ; Stroscio, Michael A. ; Turley, P. J. ; Teitsworth, S. W.
[S.l.] : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: In this paper, the commonly used but idealistic formulation of quantized optical-phonon modes for a heterostructure system with only two heterojunctions (i.e., single quantum-well structures) is extended to the more realistic case of multiheterointerface structures. By applying the macroscopic dielectric continuum approach, dispersion relations and interaction Hamiltonians for interface-phonon modes are derived for a double-barrier structure and scattering rates based on these results are used to determine the range of practical validity of the idealistic model using interaction Hamiltonians appropriate for single quantum wells with infinite barrier widths. It is found that when the dimensions of the structures are larger than approximately 30 A(ring), this simplified description can be applied to multiheterointerface structures in general with reasonable accuracy.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesDoyle, E. J. ; Kim, K. W. ; Burns, S. ; Nguyen, X. ; Peebles, W. A. ; Rhodes, T. L.
[S.l.] : American Institute of Physics (AIP)
Published 1992Staff ViewISSN: 1089-7623Source: AIP Digital ArchiveTopics: PhysicsElectrical Engineering, Measurement and Control TechnologyNotes: During a machine vent in December 1991, two new reflectometer systems were successfully installed and tested on the DIII-D tokamak. The first is an X-mode broadband system primarily intended for density profile measurements, utilizing BWO sources and covering Q and V frequency bands (33–50 and 50–75 GHz). The second system is an adaptation of a pre-existing inside launch (high field side) ECRH waveguide to provide an inside launch reflectometer capability at the same frequencies and polarization as an outside launch fixed frequency O-mode system. The new systems will have a dual role in both directly supporting the DIII-D physics program, and also acting as flexible and adaptable test beds for the development of reactor relevant reflectometer systems, such as required for ITER. Specific examples of planned measurements include investigation of possible in/out plasma asymmetries at the L–H transition and ELMs, and demonstration of routine and reliable density profile measurements. It is expected that preliminary data from the inside launch system will be available by the time of the conference. This work is supported by the U. S. Department of Energy under Grant No. DE-FG03-86-ER53225 and General Atomics subcontract SC120536 under DOE Contract No. DE-AC03-89ER51114.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: We have analyzed amplification of transverse phonons confined in quantum well (QW) heterostructures through piezoelectric electron–phonon interaction with drifting electrons. It was found that this mechanism of interaction couples the low-dimensional electrons and the shear-horizontal (SH) confined phonons. We have studied the electrostatic potential accompanying the SH waves and found that efficient interaction can be achieved for the lowest antisymmetric SH phonon branch in a narrow band of phonon frequencies. For AlGaAs QWs the amplification coefficient was calculated to be on the order of 100 cm−1 in the sub-THz phonon frequency range. These results suggest an electrical method for coherent phonon generation in the technologically well-developed AlGaAs QW heterostructures. © 2001 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesKim, K. W. ; Doyle, E. J. ; Peebles, W. A. ; Ejiri, A. ; Luhmann, N. C. ; Rettig, C. L.
[S.l.] : American Institute of Physics (AIP)
Published 1995Staff ViewISSN: 1089-7623Source: AIP Digital ArchiveTopics: PhysicsElectrical Engineering, Measurement and Control TechnologyNotes: Significant improvements have been achieved in the accuracy and reliability of broadband frequency-swept (FM) reflectometer measurements on DIII-D. This has been achieved through several improvements, the most important of which has been the application of digital complex demodulation (CDM) analysis software, which can extract signal phase with subfringe accuracy. Using this new analysis technique, results from the broadband FM system look very promising: reflectometer measurements show excellent agreement with Thomson profiles in Ohmic and H-mode plasmas, and good agreement with Thomson data in L-mode. Clear resolution of the steep edge density profile in H-mode plasmas, where very small phase shifts are involved, confirm the accuracy of the system calibration and performance. © 1995 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesKim, K. W. ; Doyle, E. J. ; Peebles, W. A. ; Ejiri, A. ; Luhmann, N. C. ; Rettig, C. L.
[S.l.] : American Institute of Physics (AIP)
Published 1995Staff ViewISSN: 1089-7623Source: AIP Digital ArchiveTopics: PhysicsElectrical Engineering, Measurement and Control TechnologyNotes: Significant improvements have been achieved in the accuracy and reliability of broadband frequency-swept (FM) reflectometer measurements on DIII-D. This has been achieved through several improvements, the most important of which has been the application of digital complex demodulation (CDM) analysis software, which can extract signal phase with subfringe accuracy. Using this new analysis technique, results from the broadband FM system look very promising: reflectometer measurements show excellent agreement with Thomson profiles in Ohmic and H-mode plasmas, and good agreement with Thomson data in L-mode. Clear resolution of the steep edge density profile in H-mode plasmas, where very small phase shifts are involved, confirm the accuracy of the system calibration and performance. © 1995 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesRhodes, T. L. ; Doyle, E. J. ; Nguyen, X. V. ; Kim, K. W. ; Peebles, W. A.
[S.l.] : American Institute of Physics (AIP)
Published 1997Staff ViewISSN: 1089-7623Source: AIP Digital ArchiveTopics: PhysicsElectrical Engineering, Measurement and Control TechnologyNotes: Divertor density profiles, asymmetries, turbulence, and MARFE diagnosis are extremely important and affect the divertor design process for ITER and other future devices. In addition, a functioning divertor density profile system will be essential for the operation of these machines. It is thus critical to prototype and demonstrate diagnostics capable of operating in a divertor environment. To meet these needs a divertor reflectometer system has been designed and installed on DIII-D. The design stresses flexibility, modularity, and simplicity. It consists of a circular, smoothwall, overmoded waveguide followed by a TE11⇒HE11 mode converter (the HE11 mode is a low loss Gaussian mode with a very symmetric radiation pattern, optimal for this use) thus allowing use of an arbitrary polarization (fpe,fLH,fRH). The design provides for testing of a variety of antennas/probing directions including: upward to probe the X-point region, including MARFEs, sideways to probe outboard/inboard divertor legs, and oppositely directed to probe both divertor legs simultaneously. System design, operational considerations, and experimental data are presented. © 1997 American Institute of Physics.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesLee, J. H. ; Kim, K. W. ; Yoon, M. Y. ; Lee, J. Y. ; Kim, C. J. ; Sim, S. S.
Oxford, UK : Blackwell Science Ltd
Published 2005Staff ViewISSN: 1474-8673Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: Chemistry and PharmacologyMedicineNotes: 1 To investigate anti-inflammatory activity of organic germanium, we measured the effect of germanium-concentrated yeast on arachidonic acid release, prostaglandin E2 (PGE2) production, histamine release, and intracellular H2O2 or hydroperoxide generation in RBL 2H3 cells, and carrageenan-induced paw oedema in rats. 2 Germanium-concentrated yeast dose-dependently inhibited carrageenan-induced paw oedema, suggesting that germanium-concentrated yeast has anti-inflammatory activity in acute inflammation. 3 Germanium-concentrated yeast significantly inhibited melittin-induced arachidonic acid release and PGE2 production in RBL 2H3 cells. 4 Germanium-concentrated yeast did not affect melittin-induced histamine release and silica-induced intracellular H2O2 or hydroperoxide generation in RBL 2H3 cells. 5 These results suggest that anti-inflammatory activity of germanium-concentrated yeast appears partly to be related to the inhibition of arachidonic acid release and PGE2 production in RBL 2H3 cells.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesMansour, N. S. ; Kim, K. W. ; Littlejohn, M. A.
[S.l.] : American Institute of Physics (AIP)
Published 1995Staff ViewISSN: 1089-7550Source: AIP Digital ArchiveTopics: PhysicsNotes: This paper describes characteristic electron transport properties for GaN in bulk and quantum well structures. First, ensemble Monte Carlo calculations of steady-state electron drift velocity in bulk GaN are presented as a function of applied electric field for different lattice temperatures. At 300 K, the calculated peak steady-state drift velocity is 2.8×107 cm/s and the threshold field is 160 kV/cm. It is found that the peak steady-state electron drift velocity decreases only slightly by about 20% as the temperature increases from 300 to 600 K while the threshold field increases slightly by about 20%. Therefore, in addition to its high temperature stability, GaN has a low temperature coefficient making it ideal for high temperature applications. For electron transport in heterostructures, quantum mechanical calculations of the electron capture rate in GaN-based quantum wells as a function of well thickness are also presented. An oscillatory behavior of the electron capture rate as a function of quantum well thickness is observed. It is found that the electron capture time oscillates between 2 and 30 ps, which is about an order of magnitude greater than capture times in GaAs quantum wells. The amplitude of oscillations decreased as the well thickness increased. These results suggest that electron transport and carrier collection in GaN are efficient processes for improved electronic and optoelectronic devices. © 1995 American Institute of Physics.Type of Medium: Electronic ResourceURL: