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

5 Dec 2011

Volume 99, Issue 23, Articles (23xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 99, 233701 (2011); http://dx.doi.org/10.1063/1.3651756 (3 pages)

Melis Hazar, Robert L. Steward, Jr., Chia-Jung Chang, Cynthia J. Orndoff, Yukai Zeng, Mon-Shu Ho, Philip R. LeDuc, and Chao-Min Cheng
Enlarge Image | Read More
Return to All Sections
back to top
RSS Feeds

Analysis of effective mobility and hall effect mobility in high-k based In0.75Ga0.25As metal-oxide-semiconductor high-electron-mobility transistors

M. A. Negara, D. Veksler, J. Huang, G. Ghibaudo, P. K. Hurley, G. Bersuker, N. Goel, and P. Kirsch

Appl. Phys. Lett. 99, 232101 (2011); http://dx.doi.org/10.1063/1.3665033 (3 pages) | Cited 2 times

Online Publication Date: 5 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report an In0.75Ga0.25As metal-oxide-semiconductor high-electron-mobility transistor with a peak Hall mobility of 8300 cm2/Vs at a carrier density of 2 × 1012 cm−2. Comparison of split capacitance-voltage (CV) and Hall Effect measurements for the extracted electron mobility have shown that the split-CV can lead to an overestimation of the channel carrier concentration and a corresponding underestimation of electron mobility. An analysis of the electron density dependence versus gate voltage allows quantifying the inaccuracy of the split-CV technique. Finally, the analysis supported by multi-channel conduction simulations indicates presence of carriers spill over into the top InP barrier layer at high gate voltages.
Show PACS
85.30.Tv Field effect devices

X-ray radiation effects in multilayer epitaxial graphene

Jeremy Hicks, Rajan Arora, Eleazar Kenyon, Partha S. Chakraborty, Holly Tinkey, John Hankinson, Claire Berger, Walt A. de Heer, Edward H. Conrad, and John D. Cressler

Appl. Phys. Lett. 99, 232102 (2011); http://dx.doi.org/10.1063/1.3665953 (3 pages)

Online Publication Date: 5 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We characterize multilayer graphene grown on C-face SiC before and after exposure to a total ionizing dose of 12 Mrad(SiO2) using a 10 keV x-ray source. While we observe the partial peeling of the top graphene layers and the appearance of a modest Raman D-peak, we find that the electrical characteristics (mobility, sheet resistivity, free carrier concentration) of the material are mostly unaffected by radiation exposure. Combined with x-ray photoelectron spectroscopy data showing numerous carbon-oxygen bonds after irradiation, we conclude that the primary damage mechanism is through surface etching from reactive oxygen species created by the x-rays.
Show PACS
81.65.Cf Surface cleaning, etching, patterning
61.48.Gh Structure of graphene
78.67.Wj Optical properties of graphene
61.80.Cb X-ray effects
73.61.Wp Fullerenes and related materials
78.30.Na Fullerenes and related materials

Effect of hydrogen on the chemical bonding and band structure at the Al2O3/In0.53Ga0.47As interface

Pini Shekhter, Lior Kornblum, Zuoguang Liu, Sharon Cui, T. P. Ma, and Moshe Eizenberg

Appl. Phys. Lett. 99, 232103 (2011); http://dx.doi.org/10.1063/1.3664778 (3 pages) | Cited 3 times

Online Publication Date: 5 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Surface passivation of high mobility semiconductors such as InGaAs is a crucial bottleneck towards their integration in metal-oxide-semiconductor devices. The chemical structure and band offsets of InGaAs-Al2O3 with different passivations were investigated by x-ray photoelectron spectroscopy. Pre-deposition forming gas plasma treatment is shown to significantly improve the chemistry of S-passivated InGaAs surface, on which the Al2O3 is deposited by the molecular atomic deposition technique. Moreover, the change in the surface chemistry was found to correlate with a difference of 0.8 eV in the band offsets at the interface. This may offer insights on Fermi level pinning in such systems.
Show PACS
81.65.Rv Passivation
68.47.Fg Semiconductor surfaces
73.20.At Surface states, band structure, electron density of states
71.20.-b Electron density of states and band structure of crystalline solids
82.65.+r Surface and interface chemistry; heterogeneous catalysis at surfaces
79.60.Jv Interfaces; heterostructures; nanostructures

A transfer technique for high mobility graphene devices on commercially available hexagonal boron nitride

P. J. Zomer, S. P. Dash, N. Tombros, and B. J. van Wees

Appl. Phys. Lett. 99, 232104 (2011); http://dx.doi.org/10.1063/1.3665405 (3 pages) | Cited 14 times

Online Publication Date: 6 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We present electronic transport measurements of single and bilayer graphene on commercially available hexagonal boron nitride. We extract mobilities as high as 125 000 cm2 V−1 s−1 at room temperature and 275 000 cm2 V−1 s−1 at 4.2 K. The excellent quality is supported by the early development of the ν = 1 quantum Hall plateau at a magnetic field of 5 T and temperature of 4.2 K. We also present a fast, simple, and accurate transfer technique of graphene to hexagonal boron nitride crystals. This technique yields atomically flat graphene on boron nitride which is almost completely free of bubbles or wrinkles. The potential of commercially available boron nitride combined with our transfer technique makes high mobility graphene devices more accessible.
Show PACS
81.05.ue Graphene

AC conductance measurement and analysis of the conduction processes in HfOx based resistive switching memory

Shimeng Yu, Rakesh Jeyasingh, Yi Wu, and H.-S. Philip Wong

Appl. Phys. Lett. 99, 232105 (2011); http://dx.doi.org/10.1063/1.3663968 (3 pages) | Cited 4 times

Online Publication Date: 6 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Impedance spectroscopy and AC conductance measurement were performed on HfOx based resistive switching memory. The fβ-like AC conductance is observable above a corner frequency for high resistance state (HRS). The index β is about 2 and is independent of DC bias or resistance value of different HRSs, suggesting that electron hopping between the nearest neighbor traps within the conductive filaments (CFs) is responsible for the measured AC conductance. The corner frequency shows up in a lower frequency regime for a higher HRS, indicating that a larger tunneling gap is formed between the electrode and the residual CFs.
Show PACS
84.30.Sk Pulse and digital circuits

Study of surface passivation of crystalline silicon with amorphous silicon carbide deposited by plasma enhanced chemical vapor deposition

D. Klein and M. Kunst

Appl. Phys. Lett. 99, 232106 (2011); http://dx.doi.org/10.1063/1.3665617 (3 pages)

Online Publication Date: 6 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electrical passivation induced by a silicon carbide coating deposited on mono-crystalline silicon substrate was investigated by means of photo-conductivity measurements. Roles of the fixed charges and surface defects were compared with silicon nitride coating. The passivation mechanisms were found to be the same as for silicon nitride but a smaller number of fixed charges in the range of the silicon oxide was calculated.
Show PACS
81.65.Rv Passivation
72.40.+w Photoconduction and photovoltaic effects
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Effects of interface roughness scattering on radio frequency performance of silicon nanowire transistors

Sung Geun Kim, Mathieu Luisier, Timothy B. Boykin, and Gerhard Klimeck

Appl. Phys. Lett. 99, 232107 (2011); http://dx.doi.org/10.1063/1.3665939 (3 pages)

Online Publication Date: 6 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effects of an atomistic interface roughness in n-type silicon nanowire transistors (SiNWT) on the radio frequency performance are analyzed. Interface roughness scattering (IRS) is statistically investigated through a three dimensional full–band quantum transport simulation based on the sp3d5s* tight–binding model. As the diameter of the SiNWT is scaled down below 3 nm, IRS causes a significant reduction of the cut-off frequency. The fluctuations of the conduction band edge due to the rough surface lead to a reflection of electrons through mode-mismatch. This effect reduces the velocity of electrons and hence the transconductance considerably causing a cut-off frequency reduction.
Show PACS
85.30.Tv Field effect devices

Atom probe study of Cu-poor to Cu-rich transition during Cu(In,Ga)Se2 growth

F. Couzinie-Devy, E. Cadel, N. Barreau, L. Arzel, and P. Pareige

Appl. Phys. Lett. 99, 232108 (2011); http://dx.doi.org/10.1063/1.3665948 (3 pages) | Cited 1 time

Online Publication Date: 6 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Atomic scale chemistry of polycrystalline Cu(In,Ga)Se2 (CIGSe) thin film has been characterized at key points of the 3-stage process using atom probe tomography. 3D atom distributions have been reconstructed when the layer is Cu-poor ([Cu]/([Ga] + [In]) < 1), Cu-rich ([Cu]/([Ga] + [In]) > 1), and at the end of the process. Particular attention has been devoted to grain boundary composition and Na atomic distribution within the CIGSe layer. Significant variation of composition is highlighted during the growing process, providing fundamental information helping the understanding of high efficiency CIGSe formation.
Show PACS
61.72.Mm Grain and twin boundaries
82.80.Ej X-ray, Mössbauer, and other γ-ray spectroscopic analysis methods

Multiple scattering theory of quasiparticles on a topological insulator surface

Zhen-Guo Fu, Ping Zhang, Zhigang Wang, and Shu-Shen Li

Appl. Phys. Lett. 99, 232109 (2011); http://dx.doi.org/10.1063/1.3665254 (3 pages) | Cited 2 times

Online Publication Date: 7 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We develop a general multiple-scattering partial-wave theory for topological insulator (TI) surfaces and derive cross sections (CSs) for single- and two-centered scattering. We show that on gapped TI surfaces the symmetry of the differential CS is reduced, and that backscattering occurs. A sharp resonance peak in the total CS Λtot of heights 30–55 nm is found at the band edge ∼50 meV, which could be useful in determining energy gaps on TI surfaces. Interference effects are obvious in CSs from quasiparticle scattering off two scattering centers, and additional resonance peaks are introduced in Λtot around ∼233 meV associated with higher-order partial-waves.
Show PACS
03.65.Nk Scattering theory
73.20.At Surface states, band structure, electron density of states

Quantum Hall effect on centimeter scale chemical vapor deposited graphene films

Tian Shen, Wei Wu, Qingkai Yu, Curt A. Richter, Randolph Elmquist, David Newell, and Yong P. Chen

Appl. Phys. Lett. 99, 232110 (2011); http://dx.doi.org/10.1063/1.3663972 (3 pages) | Cited 3 times

Online Publication Date: 7 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report observations of well developed half integer quantum Hall effect on mono layer graphene films of 7 mm × 7 mm in size. The graphene films are grown by chemical vapor deposition on copper, then transferred to SiO2/Si substrates, with typical carrier mobilities ≈4000 cm2/Vs. The large size graphene with excellent quality and electronic homogeneity demonstrated in this work is promising for graphene-based quantum Hall resistance standards and can also facilitate a wide range of experiments on quantum Hall physics of graphene and practical applications exploiting the exceptional properties of graphene.
Show PACS
81.05.ue Graphene
73.43.-f Quantum Hall effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)
73.61.Wp Fullerenes and related materials
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Electronic transport behavior of off-stoichiometric La and Nb doped SrxTiyO3−δ epitaxial thin films and donor doped single-crystalline SrTiO3

J. D. Baniecki, M. Ishii, H. Aso, K. Kobayashi, K. Kurihara, K. Yamanaka, A. Vailionis, and R. Schafranek

Appl. Phys. Lett. 99, 232111 (2011); http://dx.doi.org/10.1063/1.3664397 (3 pages) | Cited 2 times

Online Publication Date: 7 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Above room temperature electronic transport properties of SrxTiyO3−δ films with cation A/B = (La + Sr/Nb + Ti) ratios of 0.9 to 1.2 are compared to STO single crystals with combined Hall carrier densities of 3 × 1016 cm−3 ≤ nH ≤ 1022 cm−3. In contrast to Hall mobility which is single crystal-like (μH ≈ 6 cm2/Vs) only near A/B = 1, the Seebeck coefficient (S) is single crystal-like over a range of nonstoichiometry. For nH < 1020 cm−3, S is well described by nondegenerate band-like transport with a constant effective mass m∗/mo ≈ 5–8. For nH > 1021 cm−3, S is metallic-like with m∗/mo ∼ 8. No marked increase in m∗ with decreasing nH owing to a carrier filling dependence is observed.
Show PACS
73.61.Ng Insulators
61.72.up Other materials
61.66.Bi Elemental solids
61.66.Dk Alloys
68.55.aj Insulators
73.50.Lw Thermoelectric effects
73.50.Jt Galvanomagnetic and other magnetotransport effects (including thermomagnetic effects)

On the true optical properties of zinc nitride

C. García Núñez, J. L. Pau, M. J. Hernández, M. Cervera, and J. Piqueras

Appl. Phys. Lett. 99, 232112 (2011); http://dx.doi.org/10.1063/1.3663859 (3 pages) | Cited 2 times

Online Publication Date: 8 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Refractive index (n) and extinction coefficient (k) of Zn3N2 layers deposited by radio-frequency magnetron sputtering at temperatures (Ts) between 298 and 523 K were determined by spectroscopic ellipsometry. Results showed strong variations of the apparent optical constants with Ts and time attributed to surface effects. Resonant Rutherford backscattering and spectroscopic ellipsometry confirmed the formation of a ZnO surface layer provoked by the ambient exposure. Samples grown at low Ts presented the lowest surface roughness and exhibited 2.0 < n < 2.8 and 0.6 < k < 1.0 in the 1.5–4.5 eV energy range. The extracted n and k values accurately reproduced the reflectance properties.
Show PACS
78.66.Nk Insulators
68.35.B- Structure of clean surfaces (and surface reconstruction)
79.20.Rf Atomic, molecular, and ion beam impact and interactions with surfaces
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
81.15.Cd Deposition by sputtering
68.55.aj Insulators

Anomalously high thermoelectric power factor in epitaxial ScN thin films

Sit Kerdsongpanya, Ngo Van Nong, Nini Pryds, Agnė Žukauskaitė, Jens Jensen, Jens Birch, Jun Lu, Lars Hultman, Gunilla Wingqvist, and Per Eklund

Appl. Phys. Lett. 99, 232113 (2011); http://dx.doi.org/10.1063/1.3665945 (3 pages) | Cited 3 times

Online Publication Date: 8 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Thermoelectric properties of ScN thin films grown by reactive magnetron sputtering on Al2O3(0001) wafers are reported. X-ray diffraction and elastic recoil detection analyses show that the composition of the films is close to stoichiometry with trace amounts (∼1 at. % in total) of C, O, and F. We found that the ScN thin-film exhibits a rather low electrical resistivity of ∼2.94 μΩm, while its Seebeck coefficient is approximately ∼−86 μV/K at 800 K, yielding a power factor of ∼2.5 × 10−3 W/mK2. This value is anomalously high for common transition-metal nitrides.
Show PACS
73.50.Lw Thermoelectric effects
73.61.Ng Insulators
81.15.Cd Deposition by sputtering
82.80.-d Chemical analysis and related physical methods of analysis
68.55.Nq Composition and phase identification
72.20.Pa Thermoelectric and thermomagnetic effects

Irregular spectral position of E || c component of polarized photoluminescence from m-plane InGaN/GaN multiple quantum wells grown on LiAlO2

C. Mauder, E. V. Lutsenko, M. V. Rzheutski, B. Reuters, V. Z. Zubialevich, V. N. Pavlovskii, G. P. Yablonskii, M. Heuken, H. Kalisch, and A. Vescan

Appl. Phys. Lett. 99, 232114 (2011); http://dx.doi.org/10.1063/1.3667199 (3 pages)

Online Publication Date: 9 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Polarized temperature dependent photoluminescence (PL) and room temperature (RT) photocurrent spectra of m-plane InGaN/GaN multiple quantum wells grown on LiAlO2 with In content xIn = 5%-30% were studied. As expected, higher xIn leads to larger strain in the wells and enhances both the splitting between the two highest valence subbands and the RT PL degree of polarization. At low temperatures, an irregular red-shift of the PL component with polarization E || c relative to E ⊥ c is observed, which is ascribed to the contribution of recombination of holes localized at band tails within the second highest valence subband.
Show PACS
78.55.Cr III-V semiconductors
68.65.Fg Quantum wells
79.60.Bm Clean metal, semiconductor, and insulator surfaces
81.07.St Quantum wells
78.67.De Quantum wells
81.05.Ea III-V semiconductors

The two dimensional electron system as a nanoantenna in the microwave and terahertz bands

Jesús Iñarrea

Appl. Phys. Lett. 99, 232115 (2011); http://dx.doi.org/10.1063/1.3668108 (3 pages)

Online Publication Date: 9 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We study the magnetoresistance of two-dimensional electron systems under several radiation sources of different frequencies for moderate power. We use the model of radiation-driven electron orbits extended to this regime. First, we consider the case of two different radiations and we find a regime of superposition or interference of harmonic motions, i.e., a modulated magnetoresistance response with pulses and beats. Finally, we consider a multiple photoexcitation case where we propose the two-dimensional electron system as a potential nanoantenna device or ultrasensitive detector for the microwave and terahertz bands. Thus, these results could be of special interest in nanophotonics and nanoelectronics.
Show PACS
84.40.-x Radiowave and microwave (including millimeter wave) technology

Electrostatic carrier doping of GdTiO3/SrTiO3 interfaces

Pouya Moetakef, Tyler A. Cain, Daniel G. Ouellette, Jack Y. Zhang, Dmitri O. Klenov, Anderson Janotti, Chris G. Van de Walle, Siddharth Rajan, S. James Allen, and Susanne Stemmer

Appl. Phys. Lett. 99, 232116 (2011); http://dx.doi.org/10.1063/1.3669402 (4 pages) | Cited 14 times

Online Publication Date: 9 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Heterostructures and superlattices consisting of a prototype Mott insulator, GdTiO3, and the band insulator SrTiO3 are grown by molecular beam epitaxy and show intrinsic electronic reconstruction, approximately ½ electron per surface unit cell at each GdTiO3/SrTiO3 interface. The sheet carrier densities in all structures containing more than one unit cell of SrTiO3 are independent of layer thicknesses and growth sequences, indicating that the mobile carriers are in a high concentration, two-dimensional electron gas bound to the interface. These carrier densities closely meet the electrostatic requirements for compensating the fixed charge at these polar interfaces. Based on the experimental results, insights into interfacial band alignments, charge distribution, and the influence of different electrostatic boundary conditions are obtained.
Show PACS
73.40.-c Electronic transport in interface structures
61.72.up Other materials
81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
72.20.Fr Low-field transport and mobility; piezoresistance

Mg-induced terahertz transparency of indium nitride films

H. Ahn, J.-W. Chia, H.-M. Lee, Y.-L. Hong, and S. Gwo

Appl. Phys. Lett. 99, 232117 (2011); http://dx.doi.org/10.1063/1.3669538 (3 pages)

Online Publication Date: 9 December 2011

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Terahertz time-domain spectroscopy (THz-TDS) has been used to investigate electrical properties of Mg-doped indium nitride (InN). Mg-doping in InN was found to significantly increase terahertz transmittance. THz-TDS analysis based on the Drude model shows that this high transmittance from Mg-doped InN is mainly due to the reduction in mobility associated with ionized dopants. The Hall-effect-measured mobility is typically lower than the THz-TDS-measured mobility for the same samples. However, the results of both measurements have the same slope in the linear relation between mobility and density. By introducing a compensation ratio of ∼0.2, an excellent agreement in mobilities of two methods is obtained.
Show PACS
78.66.Fd III-V semiconductors
78.70.Gq Microwave and radio-frequency interactions
61.72.uj III-V and II-VI semiconductors
72.20.My Galvanomagnetic and other magnetotransport effects
73.61.Ey III-V semiconductors
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close