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

Flickr Twitter iResearch App Facebook

SECTION LISTING

BROWSE VOLUMES

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

3 May 2004

Volume 84, Issue 18, pp. 3435-3703

Issue Cover Spotlight Figure

Appl. Phys. Lett. 84, 3648 (2004); http://dx.doi.org/10.1063/1.1737470 (3 pages)

Jingbo Li and Lin-Wang Wang
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Impact of dislocations on minority carrier electron and hole lifetimes in GaAs grown on metamorphic SiGe substrates

C. L. Andre, J. J. Boeckl, D. M. Wilt, A. J. Pitera, M. L. Lee, E. A. Fitzgerald, B. M. Keyes, and S. A. Ringel

Appl. Phys. Lett. 84, 3447 (2004); http://dx.doi.org/10.1063/1.1736318 (3 pages) | Cited 7 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The minority carrier lifetime of electrons (τn) in p-type GaAs double heterostructures grown on GaAs substrates and compositionally graded Ge/Si1−xGex/Si (SiGe) substrates with varying threading dislocation densities (TDDs) were measured at room temperature using time-resolved photoluminescence. The electron lifetimes for homoepitaxial GaAs and GaAs grown on SiGe (TDD ∼ 1×106 cm−2) with a dopant concentration of 2×1017 cm−3 were ∼ 21 and ∼ 1.5 ns, respectively. The electron lifetime measured on SiGe was substantially lower than the previously measured minority carrier hole lifetime (τp) of ∼ 10 ns, for n-type GaAs grown on SiGe substrates with a similar residual TDD and dopant concentration. The reduced lifetime for electrons is a consequence of their higher mobility, which yields an increased sensitivity to the presence of dislocations in GaAs grown on metamorphic buffers. The disparity in dislocation sensitivity for electron and hole recombination has significant implications for metamorphic III-V devices. © 2004 American Institute of Physics.
Show PACS
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
72.20.Fr Low-field transport and mobility; piezoresistance
73.50.Dn Low-field transport and mobility; piezoresistance
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
73.50.Gr Charge carriers: generation, recombination, lifetime, trapping, mean free paths
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
61.72.S- Impurities in crystals

High doping incorporation on (311)B InP/InGaAs by metalorganic chemical vapor deposition and its application to tunnel junction fabrication

Yae L. Okuno, Steven P. DenBaars, and John E. Bowers

Appl. Phys. Lett. 84, 3483 (2004); http://dx.doi.org/10.1063/1.1737798 (3 pages) | Cited 1 time

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigated the doping characteristics of InP/InGaAs on the (311)B plane by metalorganic chemical vapor deposition using metalorganic group-V regents. For both n-type Si doping and p-type Zn doping, we found that dopant incorporation is higher on the (311)B plane than the (100) plane. Applying this result, we grew a tunnel junction on (311)B InP substrates at a constant growth temperature. The junction showed good current–voltage characteristics and is promising for device applications. © 2004 American Institute of Physics.
Show PACS
61.72.uj III-V and II-VI semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
61.72.S- Impurities in crystals

Very high spin polarization in GaAs by injection from a (Ga,Mn)As Zener diode

P. Van Dorpe, Z. Liu, W. Van Roy, V. F. Motsnyi, M. Sawicki, G. Borghs, and J. De Boeck

Appl. Phys. Lett. 84, 3495 (2004); http://dx.doi.org/10.1063/1.1738515 (3 pages) | Cited 63 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We demonstrate an electrically injected electron spin polarization in GaAs of 80% at 4.6 K by interband tunneling from the valence band of (Ga,Mn)As into an (Al,Ga)As light-emitting diode. The polarization is analyzed by the oblique Hanle effect and vanishes at 120 K, the Curie temperature of the (Ga,Mn)As injector. The temperature and the bias dependence of the polarization are explained in terms of the properties of the (Ga,Mn)As/GaAs diode. © 2004 American Institute of Physics.
Show PACS
85.75.Mm Spin polarized resonant tunnel junctions
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
85.30.Mn Junction breakdown and tunneling devices (including resonance tunneling devices)
75.50.Pp Magnetic semiconductors
75.50.Dd Nonmetallic ferromagnetic materials
75.40.Cx Static properties (order parameter, static susceptibility, heat capacities, critical exponents, etc.)
85.75.-d Magnetoelectronics; spintronics: devices exploiting spin polarized transport or integrated magnetic fields
85.60.Jb Light-emitting devices
73.20.At Surface states, band structure, electron density of states

Suppressing of optical quenching of deep defect-to-band transitions in AlGaN and GaN/AlGaN heterostructures

H. Witte, E. Schrenk, K. Flügge, A. Krtschil, M. Lisker, A. Krost, J. Christen, B. Kuhn, and F. Scholz

Appl. Phys. Lett. 84, 3498 (2004); http://dx.doi.org/10.1063/1.1738517 (3 pages) | Cited 2 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Quenching of photocurrent spectroscopy and thermally stimulated currents has been investigated in undoped AlGaN layers and GaN/AlGaN heterostructures grown by metalorganic vapor phase epitaxy on sapphire substrates. The quenching was induced by an additional illumination as well as by an excitation with light below bandgap energy, respectively. In GaN layers, mainly the thermal defect emission band between 210 and 300 K is involved in the quenching processes and there are strong indications of a reduction of the band by incorporation of aluminum. In AlGaN layers, a decrease of quenching with increasing Al content is observed in accordance to a reduction of the height of the thermal emission between 210 and 300 K in these layers. These results are supported by quenching experiments in AlGaN/GaN heterostructures. © 2004 American Institute of Physics.
Show PACS
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
81.15.Kk Vapor phase epitaxy; growth from vapor phase
78.55.Cr III-V semiconductors
78.66.Fd III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
71.55.Eq III-V semiconductors
79.60.Jv Interfaces; heterostructures; nanostructures

Growth and properties of molecular beam epitaxially grown ferromagnetic Fe-doped TiO2 rutile films on TiO2(110)

Y. J. Kim, S. Thevuthasan, T. Droubay, A. S. Lea, C. M. Wang, V. Shutthanandan, S. A. Chambers, R. P. Sears, B. Taylor, and B. Sinkovic

Appl. Phys. Lett. 84, 3531 (2004); http://dx.doi.org/10.1063/1.1703845 (3 pages) | Cited 39 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have grown epitaxial Fe-doped TiO2 rutile films on rutile TiO2(110) substrates, and have explored the resulting compositional, structural, morphological and magnetic properties. Clusters of mixed TiO2 rutile and Fe3O4 form on the surface of a continuous rutile epitaxial film during growth. Room-temperature ferromagnetism is observed, and is associated with the formation of secondary phase Fe3O4 rather than a true diluted magnetic oxide semiconductor. © 2004 American Institute of Physics.
Show PACS
75.50.Pp Magnetic semiconductors
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.A- Nucleation and growth
68.55.-a Thin film structure and morphology
68.37.Lp Transmission electron microscopy (TEM)
68.35.B- Structure of clean surfaces (and surface reconstruction)
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects
78.20.Ls Magneto-optical effects
78.70.Dm X-ray absorption spectra
75.50.Dd Nonmetallic ferromagnetic materials

Sb-mediated growth of Si-doped AlGaAs by molecular-beam epitaxy

Yu. G. Sadofyev, S. R. Johnson, S. A. Chaparro, Y. Cao, D. Ding, J.-B. Wang, K. Franzreb, and Y.-H. Zhang

Appl. Phys. Lett. 84, 3546 (2004); http://dx.doi.org/10.1063/1.1715153 (3 pages) | Cited 4 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The Sb-mediated growth of Al0.65Ga0.35As is studied for Sb/III flux ratios from 0 to 2% and growth temperatures from 580 to 720 °C. The electrical properties and surface morphology are found to depend strongly on both the growth temperature and the Sb flux. As an isoelectronic dopant, Sb improves the conductivity of n-Al0.65Ga0.35As with the highest conductivities occurring at the highest growth temperatures. As a surfactant, Sb improves the surface morphology at all growth temperatures, with the most dramatic improvement occurring at 670 °C. The smoothest surface (0.2 nm rms roughness) was obtained at 700 °C using a Sb/III flux ratio of 0.02. Furthermore, we have demonstrated that the use of Sb during the molecular-beam-epitaxy growth of AlGaAs effectively eliminates the “forbidden temperature gap.” © 2004 American Institute of Physics.
Show PACS
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.55.-a Thin film structure and morphology
61.72.uj III-V and II-VI semiconductors
82.70.Uv Surfactants, micellar solutions, vesicles, lamellae, amphiphilic systems, (hydrophilic and hydrophobic interactions)
68.35.B- Structure of clean surfaces (and surface reconstruction)
73.61.Ey III-V semiconductors

Room-temperature operation of an electrically driven terahertz modulator

T. Kleine-Ostmann, P. Dawson, K. Pierz, G. Hein, and M. Koch

Appl. Phys. Lett. 84, 3555 (2004); http://dx.doi.org/10.1063/1.1723689 (3 pages) | Cited 44 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, we report the room-temperature operation of an electrically controlled THz modulator. The modulation is achieved by reducing the electron density in a gated two-dimensional electron gas structure, which leads to an increase in the transmitted intensity of an incident beam of THz radiation. By depleting an electron gas of density 1012 cm−2, we achieved a maximum modulation depth of 3% for a pulse of terahertz radiation covering the range of frequencies from 0.1 to 2 THz. © 2004 American Institute of Physics.
Show PACS
42.79.Hp Optical processors, correlators, and modulators
84.40.-x Radiowave and microwave (including millimeter wave) technology

Spin relaxation dynamics in highly uniform InAs quantum dots

A. Tackeuchi, R. Ohtsubo, K. Yamaguchi, M. Murayama, T. Kitamura, T. Kuroda, and T. Takagahara

Appl. Phys. Lett. 84, 3576 (2004); http://dx.doi.org/10.1063/1.1737068 (3 pages) | Cited 24 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We have investigated carrier spin dynamics in highly uniform self-assembled InAs quantum dots. The highly uniform quantum dots allowed us to observe the spin dynamics in the ground state and that in the second state separately, without the disturbance of inhomogeneous broadening. The spin relaxation times in the ground state and the second state were measured to be 1.0 and 0.6 ns, respectively. Our measurements reveal the absence of the carrier density dependence of the spin relaxation time. The measured spin relaxation time decreases rapidly from 1.1 ns at 10 K to 200 ps at 130 K. This large change in the spin relaxation time is well explained in terms of the mechanism of acoustic phonon emission. © 2004 American Institute of Physics.
Show PACS
78.55.Cr III-V semiconductors
73.63.Kv Quantum dots
72.25.Rb Spin relaxation and scattering
63.22.-m Phonons or vibrational states in low-dimensional structures and nanoscale materials
78.67.Hc Quantum dots

High-germanium-content SiGe islands formed on compliant oxide by SiGe oxidation

Haizhou Yin, K. D. Hobart, F. J. Kub, S. R. Shieh, T. S. Duffy, and J. C. Sturm

Appl. Phys. Lett. 84, 3624 (2004); http://dx.doi.org/10.1063/1.1738514 (3 pages) | Cited 1 time

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The oxidation of Si1−xGex islands on a compliant viscous borophosphorosilicate glass (BPSG) was utilized to achieve nearly fully relaxed Si1−xGex with germanium content up to 57%. After Si1−xGex islands were formed on BPSG by layer transfer, dry oxidation was carried out to form pure silicon dioxide on the top and to increase germanium content in the Si1−xGex layer. Surface roughening and the nonuniformity of the enhanced germanium content during the SiGe oxidation were improved by depositing a silicon dioxide capping layer before oxidation. The strain arising from the increase of germanium content was relaxed by lateral expansion of the SiGe islands, showing that dislocations were not required in the process. © 2004 American Institute of Physics.
Show PACS
81.65.Mq Oxidation
81.40.Jj Elasticity and anelasticity, stress-strain relations
62.40.+i Anelasticity, internal friction, stress relaxation, and mechanical resonances
81.05.Hd Other semiconductors
68.35.B- Structure of clean surfaces (and surface reconstruction)
65.40.De Thermal expansion; thermomechanical effects

High-frequency small-signal conductivity of hot electrons in nitride semiconductors

V. N. Sokolov, K. W. Kim, V. A. Kochelap, and D. L. Woolard

Appl. Phys. Lett. 84, 3630 (2004); http://dx.doi.org/10.1063/1.1738518 (3 pages) | Cited 2 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We investigate the small-signal conductivity of the electrons in group-III nitrides under a high steady-state electric field. The resulting calculation indicates a frequency dependence of the conductivity that is drastically different from that given by the Drude formula. A large and very fast response of the hot electrons in the nitrides is revealed. The complex conductivity is found to be finite up to the frequency of about 10 THz. For the fields above the threshold corresponding to the peak drift velocity, the calculation also predicts a frequency interval with a negative conductivity. A detailed analysis is provided on the field and frequency dependence of the dynamic conductivity at the high electric fields. © 2004 American Institute of Physics.
Show PACS
72.20.Ht High-field and nonlinear effects
72.80.Ey III-V and II-VI semiconductors
72.30.+q High-frequency effects; plasma effects

Formation of CdSe quantum dots on homoepitaxial ZnSe

S. Sadofev, S. Blumstengel, and F. Henneberger

Appl. Phys. Lett. 84, 3678 (2004); http://dx.doi.org/10.1063/1.1739273 (3 pages) | Cited 4 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
CdSe quantum dots were prepared by molecular beam epitaxy on homoepitaxially grown ZnSe (001) via thermally activated reorganization of an initially two-dimensional film. In spite of the difficulties related to the ZnSe substrate treatment prior to the epitaxial growth, atomically smooth sample surfaces could be achieved with increasing growth time and layer-by-layer growth was realized. The photoluminescence quantum yield of the quantum dots grown on homoepitaxial ZnSe is only slightly reduced in comparison to the standard epitaxy using GaAs as substrate. Distinct single-dot features were identified using a micro-optical setup. © 2004 American Institute of Physics.
Show PACS
81.07.Ta Quantum dots
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy

Field-induced nonequilibrium electron distribution and electron transport in a high-quality InN thin film grown on GaN

W. Liang, K. T. Tsen, D. K. Ferry, Hai Lu, and William J. Schaff

Appl. Phys. Lett. 84, 3681 (2004); http://dx.doi.org/10.1063/1.1739509 (3 pages) | Cited 16 times

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Nonequilibrium electron transport in a high-quality, single-crystal, wurtzite structure InN thin film grown on GaN has been investigated by picosecond Raman spectroscopy. Our experimental results show that an electron drift velocity as high as (5.0±0.5)×107 cm/s can be achieved at T = 300 K. The experimental results have been compared with ensemble Monte Carlo simulations and good agreement is obtained. From the comparison, we have also deduced that the built-in electric-field intensity inside our InN thin-film system is about 75 kV/cm. © 2004 American Institute of Physics.
Show PACS
73.50.Dn Low-field transport and mobility; piezoresistance
73.61.Ey III-V semiconductors
78.30.Fs III-V and II-VI semiconductors
81.05.Ea III-V semiconductors

Leakage behavior of the quasi-superlattice stack for multilevel charge storage

T. C. Chang, S. T. Yan, P. T. Liu, C. W. Chen, H. H. Wu, and S. M. Sze

Appl. Phys. Lett. 84, 3687 (2004); http://dx.doi.org/10.1063/1.1739514 (3 pages)

Online Publication Date: 20 April 2004

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The leakage behavior of the quasi-superlattice structure has been characterized by current–voltage measurements at room temperature and 50 K. A resonant tunnelinglike leakage characteristic is observed at low temperature. The resonant tunneling occurs at around 2, 5.2, and 7 V under a gate voltage swept from 0 to 10 V. A concise physical model is proposed to characterize the leakage mechanism of tunneling for the quasi-lattice structure and suggests that the considerations of the operating voltage for the two-bit per cell nonvolatile-memory device need to be taken into account. © 2004 American Institute of Physics.
Show PACS
85.30.-z Semiconductor devices
73.40.Lq Other semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.21.Cd Superlattices
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close