APL Nameplate
  • Volume/Page
  • Keyword
  • DOI
  • Citation
  • Advanced
   
 
 
 

Flickr Twitter iResearch App Facebook

BROWSE VOLUMES

Year Range: 
Search Issue | RSS Feeds RSS
Previous Issue Next Issue

28 Feb 2000

Volume 76, Issue 9, pp. 1083-1210

Return to All Sections
back to top
RSS Feeds

Photoluminescence of high-quality AlGaAs layers grown by molecular-beam epitaxy

K. S. Zhuravlev, A. I. Toropov, T. S. Shamirzaev, and A. K. Bakarov

Appl. Phys. Lett. 76, 1131 (2000); http://dx.doi.org/10.1063/1.125960 (3 pages) | Cited 16 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report a photoluminescence study of high-purity AlxGa1−xAs layers grown by molecular-beam epitaxy over the 0 ⩽ x ⩽ 0.295 composition range. The intense excitonic line dominates in the photoluminescence spectra of the layers. The full width at half maximum of the excitonic line is in excellent agreement with values calculated by Lee and Bajaj [J. Appl. Phys. 73, 1788 (1993)] for perfectly random alloys, and in the spectra of the layers with AlAs fractions of x = 0.15 and x = 0.209 it equals to 1.24 and 1.48 meV, respectively. A linear dependence of the exciton line intensity on excitation power evidences negligible concentration of nonradiative recombination centers in the layers. © 2000 American Institute of Physics.
Show PACS
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
81.05.Ea III-V semiconductors
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
71.35.-y Excitons and related phenomena

Multilayered gated lateral quantum dot devices

C.-T. Liang, M. Y. Simmons, C. G. Smith, Gil-Ho Kim, D. A. Ritchie, and M. Pepper

Appl. Phys. Lett. 76, 1134 (2000); http://dx.doi.org/10.1063/1.125961 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe a detailed device fabrication technique for the formation of a lateral quantum dot using a multilayered gated design. In our versatile system, a quantum dot is electrostatically defined by a split gate and two overlaying finger gates which introduce entrance and exit barriers to the dot. Periodic and continuous conductance oscillations arising from Coulomb charging effects are clearly observed in the transport properties at low temperatures. © 2000 American Institute of Physics.
Show PACS
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
85.35.Ds Quantum interference devices
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Analysis of the turn-off dynamics in polymer light-emitting diodes

D. J. Pinner, R. H. Friend, and N. Tessler

Appl. Phys. Lett. 76, 1137 (2000); http://dx.doi.org/10.1063/1.125962 (3 pages) | Cited 30 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present experimental techniques to analyze the electroluminescence (EL) of polymer light-emitting diodes following the removal of an applied voltage pulse. We explain the fast modulation of the EL intensity at turn-off in terms of the sudden reduction of the Langevin recombination rate, and extract the time evolution the device’s internal electric field at the recombination zone during the application of a voltage pulse. The results are compared to, and found to be consistent with, those of simple numerical modeling. The subsequent long-lived EL tail is analyzed to give the time evolution of the carrier distributions at the recombination zone once the voltage pulse has been removed. © 2000 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
78.66.Qn Polymers; organic compounds
78.60.Fi Electroluminescence

Energy loss rates of two-dimensional hole gases in inverted Si/Si0.8Ge0.2 heterostructures

G. Ansaripour, G. Braithwaite, M. Myronov, O. A. Mironov, E. H. C. Parker, and T. E. Whall

Appl. Phys. Lett. 76, 1140 (2000); http://dx.doi.org/10.1063/1.125963 (3 pages) | Cited 11 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated the energy loss rate of hot holes as a function of carrier temperature TC in p-type inverted modulation-doped (MD) Si/SiGe heterostructures over the carrier sheet density range (3.5–13)×1011 cm−2, at lattice temperatures of 0.34 and 1.8 K. It is found that the energy loss rate (ELR) depends significantly upon the carrier sheet density, n2D. Such an n2D dependence of ELR has not been observed previously in p-type SiGe MD structures. The extracted effective mass decreases as n2D increases, which is in agreement with recent measurements on a gated inverted sample. It is shown that the energy relaxation of the two-dimensional hole gases is dominated by unscreened acoustic phonon scattering and a deformation potential of 3.0±0.4 eV is deduced. © 2000 American Institute of Physics.
Show PACS
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.50.Fq High-field and nonlinear effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths

Band structure calculation of field emission from AlxGa1−xN as a function of stoichiometry

M. S. Chung, N. M. Miskovsky, P. H. Cutler, and N. Kumar

Appl. Phys. Lett. 76, 1143 (2000); http://dx.doi.org/10.1063/1.125964 (3 pages) | Cited 16 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The field emission current density j from the ternary alloys AlxGa1−xN is theoretically calculated as a function of stoichiometry. The material parameters of AlxGa1−xN are obtained as weighted averages of those of AlN and GaN. Using the method of W. W. Lui and M. Fukuma [J. Appl. Phys. 60, 1555(1986)], the transmission coefficients are numerically calculated using Airy functions that are solutions of the Schrödinger equation in a piecewise linear potential region. Band structure effects in the calculation of j are included using the projection of the energy ellipsoids on the emission surfaces. The results for j show a strong dependence of the field emission on the stoichiometric composition, which reflects the composition dependence of the electron affinity. The Fowler–Nordheim plots and calculated field electron energy distribution curves both exhibit structures which suggest different field-dependent transmission probabilities in the low and high field regimes. © 2000 American Institute of Physics.
Show PACS
79.70.+q Field emission, ionization, evaporation, and desorption
85.45.Db Field emitters and arrays, cold electron emitters
71.20.Nr Semiconductor compounds
61.66.Bi Elemental solids
61.66.Dk Alloys

Conduction-band offset of single InAs monolayers on GaAs

Raffaele Colombelli, Vincenzo Piazza, Antonio Badolato, Marco Lazzarino, Fabio Beltram, Winston Schoenfeld, and Pierre Petroff

Appl. Phys. Lett. 76, 1146 (2000); http://dx.doi.org/10.1063/1.125965 (3 pages) | Cited 13 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A determination of the InAs/GaAs band-offset energy is presented. Electronic-transport analysis, based on capacitance-voltage and deep-level transient spectroscopy techniques, demonstrates high crystalline quality of our sample and yields a band-offset estimate of 0.69 eV, corresponding to a band-offset ratio of 7030. The present results agree well with reported theoretical values and allow the accurate modeling of electronic states in GaAs/AlGaAs heterostructures containing InAs ultrathin layers. © 2000 American Institute of Physics.
Show PACS
73.20.At Surface states, band structure, electron density of states
71.55.Eq III-V semiconductors
71.20.Nr Semiconductor compounds
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions

Hole transport in Mg-doped GaN epilayers grown by metalorganic chemical vapor deposition

K. S. Kim, M. G. Cheong, C.-H. Hong, G. M. Yang, K. Y. Lim, E.-K. Suh, and H. J. Lee

Appl. Phys. Lett. 76, 1149 (2000); http://dx.doi.org/10.1063/1.125966 (3 pages) | Cited 15 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A two-band model involving the heavy- and light-hole bands was adopted to analyze the temperature-dependent Hall effect measured on Mg-doped p-type GaN epilayers. At 300 K, the hole concentration was determined to be nearly twice the Hall concentration estimated from the measured Hall coefficient, meanwhile the Hall mobility of heavy hole turned out to be only half of the measured one. It is shown that the scattering by space charge and acoustic deformation potential is anomalously enhanced in Mg-doped GaN, and that the light hole affects conspicuously the observed transport parameters. © 2000 American Institute of Physics.
Show PACS
73.61.Ey III-V semiconductors
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)

Direct determination of the Andreev reflection probability by means of point contact spectroscopy

M. Jakob, H. Stahl, J. Knoch, J. Appenzeller, B. Lengeler, H. Hardtdegen, and H. Lüth

Appl. Phys. Lett. 76, 1152 (2000); http://dx.doi.org/10.1063/1.125967 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF


See Also: Erratum

Show Abstract
In this letter, we describe a technique for determining the Andreev reflection probability of electrons impinging on a semiconductor–superconductor interface. A two-dimensional electron gas (2DEG) in an InGaAs/InP heterostructure is linked to a niobium superconductor. A point contact in the 2DEG emits ballistic electrons and detects the reflected carriers. The vast majority of the detected carriers are retroreflected holes because of our specific sample setup. We have found an Andreev reflection probability of up to 20%. The experimental results are compared with the predictions of two theoretical models. © 2000 American Institute of Physics.
Show PACS
73.23.Ad Ballistic transport
74.45.+c Proximity effects; Andreev reflection; SN and SNS junctions
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.61.Ey III-V semiconductors

Time-resolved electroabsorption measurement of the electron velocity-field characteristic in GaN

M. Wraback, H. Shen, J. C. Carrano, T. Li, J. C. Campbell, M. J. Schurman, and I. T. Ferguson

Appl. Phys. Lett. 76, 1155 (2000); http://dx.doi.org/10.1063/1.125968 (3 pages) | Cited 44 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A femtosecond optically detected time-of-flight technique that monitors the change in the electroabsorption associated with the transport of photogenerated carriers in a GaN p–i–n diode has been used to determine the room-temperature electron transit time and steady-state velocity as a function of electric field. The peak electron velocity of 1.9×107 cm/s, corresponding to a transit time of 2.5 ps, is attained at 225 kV/cm. The shape of the velocity-field characteristic is in qualitative agreement with theoretical predictions. © 2000 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
78.20.Jq Electro-optical effects
78.47.-p Spectroscopy of solid state dynamics
73.50.Pz Photoconduction and photovoltaic effects
85.60.Dw Photodiodes; phototransistors; photoresistors
73.61.Ey III-V semiconductors
78.66.Fd III-V semiconductors

Comparison of the electrical and thermal stability of stress- or radiation-induced leakage current in thin oxides

P. Riess, M. Ceschia, A. Paccagnella, G. Ghibaudo, and G. Pananakakis

Appl. Phys. Lett. 76, 1158 (2000); http://dx.doi.org/10.1063/1.125969 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this work, the leakage currents induced by electrical stress and by irradiation are compared. We show that the Ig–Vg characteristics of a 5.4-nm-thick oxide are very similar for both types of stresses. Moreover, we show that the electrical stability and the annealing behavior of the defects at the origin of the leakage current are very similar. We demonstrate that the radiation-induced leakage current can be fully annealed. Comparing the properties of the stress-induced leakage current and the radiation-induced leakage current, we believe that these currents are both due to the same type of defects which are supposed to be related to trapped holes. © 2000 American Institute of Physics.
Show PACS
73.61.Ng Insulators
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
61.82.Ms Insulators
68.60.Dv Thermal stability; thermal effects
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
61.72.Cc Kinetics of defect formation and annealing
84.32.Tt Capacitors
71.55.Ht Other nonmetals

Lattice and energy band engineering in AlInGaN/GaN heterostructures

M. Asif Khan, J. W. Yang, G. Simin, R. Gaska, M. S. Shur, Hans-Conrad zur Loye, G. Tamulaitis, A. Zukauskas, David J. Smith, D. Chandrasekhar, and R. Bicknell-Tassius

Appl. Phys. Lett. 76, 1161 (2000); http://dx.doi.org/10.1063/1.125970 (3 pages) | Cited 65 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on structural, optical, and electrical properties of AlxInyGa1−x−yNGaN heterostructures grown on sapphire and 6H–SiC substrates. Our results demonstrate that incorporation of In reduces the lattice mismatch, Δa, between AlInGaN and GaN, and that an In to Al ratio of close to 1:5 results in nearly strain-free heterostructures. The observed reduction in band gap, ΔEg, determined from photoluminescence measurements, is more than 1.5 times higher than estimated from the linear dependencies of Δa and ΔEg on the In molar fraction. The incorporation of In and resulting changes in the built-in strain in AlInGaN/GaN heterostructures strongly affect the transport properties of the two-dimensional electron gas at the heterointerface. The obtained results demonstrate the potential of strain energy band engineering for GaN-based electronic applications. © 2000 American Institute of Physics.
Show PACS
68.35.Ct Interface structure and roughness
68.55.-a Thin film structure and morphology
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.66.Fd III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
73.61.Ey III-V semiconductors
78.55.Cr III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
68.60.Bs Mechanical and acoustical properties
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close