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

27 Aug 2007

Volume 91, Issue 9, Articles (09xxxx)

Issue Cover Spotlight Figure

Appl. Phys. Lett. 91, 093110 (2007); http://dx.doi.org/10.1063/1.2775801 (3 pages)

M. Schmidbauer, Zh. M. Wang, Yu. I. Mazur, P. M. Lytvyn, G. J. Salamo, D. Grigoriev, P. Schäfer, R. Köhler, and M. Hanke
Enlarge Image | Read More
Page 1 of 2 Pages Return to All Sections Next Page
back to top
RSS Feeds

Universality of electron accumulation at wurtzite c- and a-plane and zinc-blende InN surfaces

P. D. C. King, T. D. Veal, C. F. McConville, F. Fuchs, J. Furthmüller, F. Bechstedt, P. Schley, R. Goldhahn, J. Schörmann, D. J. As, K. Lischka, D. Muto, H. Naoi, Y. Nanishi, Hai Lu, et al.

Appl. Phys. Lett. 91, 092101 (2007); http://dx.doi.org/10.1063/1.2775807 (3 pages) | Cited 58 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Electron accumulation is found to occur at the surface of wurtzite (11math0), (0001), and (000math) and zinc-blende (001) InN using x-ray photoemission spectroscopy. The accumulation is shown to be a universal feature of InN surfaces. This is due to the low Γ-point conduction band minimum lying significantly below the charge neutrality level.
Show PACS
73.20.At Surface states, band structure, electron density of states
79.60.Bm Clean metal, semiconductor, and insulator surfaces

Multi-quantum-well spin oscillator

L. L. Bonilla, R. Escobedo, M. Carretero, and G. Platero

Appl. Phys. Lett. 91, 092102 (2007); http://dx.doi.org/10.1063/1.2775812 (3 pages) | Cited 7 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A dc voltage biased II-VI semiconductor multi-quantum-well structure attached to normal contacts exhibits self-sustained spin polarized current oscillations if one or more of its wells are doped with Mn. Without magnetic impurities, the only configurations appearing in these structures are stationary. Analysis and numerical solution of a nonlinear spin transport model yield the minimal number of wells (four) and the ranges of doping density and spin splitting needed to find oscillations.
Show PACS
73.63.Hs Quantum wells
72.25.Dc Spin polarized transport in semiconductors
61.72.S- Impurities in crystals

Direct-current and radio-frequency characterizations of GaAs metal-insulator-semiconductor field-effect transistors enabled by self-assembled nanodielectrics

H. C. Lin, S. K. Kim, D. Chang, Y. Xuan, S. Mohammadi, P. D. Ye, G. Lu, A. Facchetti, and T. J. Marks

Appl. Phys. Lett. 91, 092103 (2007); http://dx.doi.org/10.1063/1.2776013 (3 pages)

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Direct-current and radio-frequency characterizations of GaAs metal-insulator-semiconductor field-effect transistors (MISFETs) with very thin self-assembled organic nanodielectrics (SANDs) are presented. The application of SAND on compound semiconductors offers unique opportunities for high-performance devices. Thus, 1 μm gate-length depletion-mode n-channel SAND/GaAs MISFETs exhibit low gate leakage current densities of 10−2–10−5 A/cm2, a maximum drain current of 260 mA/mm at 2 V forward gate bias, and a maximum intrinsic transconductance of 127 mS/mm. These devices achieve a current cutoff frequency (fT) of 10.6 GHz and a maximum oscillation frequency (fmax) of 6.9 GHz. Nearly hysteresis-free Ids-Vgs characteristics and low flicker noise indicate that a high-quality SAND-GaAs interface is achieved.
Show PACS
85.30.Tv Field effect devices

Effect of gas pressure on current-voltage characteristics of amorphous carbon film/silicon heterojunction

Xili Gao, Qingzhong Xue, Lanzhong Hao, Qun Li, Qingbin Zheng, and Ping Tian

Appl. Phys. Lett. 91, 092104 (2007); http://dx.doi.org/10.1063/1.2776017 (3 pages) | Cited 6 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Amorphous carbon film/n-Si (a-C/Si) junctions have been fabricated by direct current magnetron sputtering and their current-voltage (I-V) characteristics have been investigated. The results show that the gas pressure has a large effect on the reverse bias I-V characteristics of the junctions. For example, the reverse current can increase by 3300% when the gas pressure decreases from 100 000 to 100 Pa. The effect of gas pressure may be attributed to the physisorption process of gas molecules which increases the space charge width and changes the surface states of the junction.
Show PACS
73.40.-c Electronic transport in interface structures
68.43.Mn Adsorption kinetics
77.22.Jp Dielectric breakdown and space-charge effects
73.20.At Surface states, band structure, electron density of states

Change of molecular ordering in soluble acenes via solvent annealing and its effect on field-effect mobility

Wi Hyoung Lee, Do Hwan Kim, Jeong Ho Cho, Yunseok Jang, Jung Ah Lim, Donghoon Kwak, and Kilwon Cho

Appl. Phys. Lett. 91, 092105 (2007); http://dx.doi.org/10.1063/1.2768885 (3 pages) | Cited 31 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The increase of the molecular ordering and field-effect mobility in triethylsilylethynyl anthradithiophene (TES ADT) thin film transistors by solvent annealing was investigated. X-ray diffraction data revealed that TES ADT molecules crystallize with silyl groups on the substrate surface. After solvent annealing, spherulites were formed and the field-effect mobilities dramatically increased up to 0.43 cm2/V s (over 100-fold) as result of maximized overlap of π electron clouds along the in-plane direction and the formation of a continuous crystal.
Show PACS
85.30.Tv Field effect devices

Electronic structure and work function of metal gate Mo–W system

H. R. Gong and Kyeongjae Cho

Appl. Phys. Lett. 91, 092106 (2007); http://dx.doi.org/10.1063/1.2776851 (3 pages) | Cited 6 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
First principles calculation reveals that the Mo–W interface dipole is formed due to an equal loss of electrons of interface atoms, and the interface formation is energetically unfavorable with positive interface energy, signifying a tendency of phase separation of Mo and W atoms. Calculation also shows that Mo surface segregation has an important effect in reducing the work function of Mo–W alloys, and that after Mo surface segregation, the Mo–W work function becomes relatively stable when W is between 0–70 at. %. Interestingly, such a composition range seems good for work function modulation of metal gate Mo–W system.
Show PACS
73.30.+y Surface double layers, Schottky barriers, and work functions
71.20.Be Transition metals and alloys
71.15.-m Methods of electronic structure calculations
68.35.Md Surface thermodynamics, surface energies
68.35.Dv Composition, segregation; defects and impurities

Doping level dependence of electron irradiation-induced minority carrier diffusion length increase in Mg-doped GaN

O. Lopatiuk-Tirpak, L. Chernyak, Y. L. Wang, F. Ren, S. J. Pearton, and K. Gartsman

Appl. Phys. Lett. 91, 092107 (2007); http://dx.doi.org/10.1063/1.2776866 (3 pages) | Cited 2 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electron irradiation-induced increase of minority carrier diffusion length was studied as a function of hole concentration in Mg-doped GaN. Variable-temperature electron beam induced current measurements yielded activation energies of 264, 254, 171, and 144 meV for samples with hole concentrations of 2×1016, 9×1016, 3×1018, and 7×1018 cm−3, respectively. This carrier concentration dependence of the activation energy for the effects of electron irradiation was found to be consistent with Mg acceptors, indicating the involvement of the latter levels in the irradiation-induced diffusion length increase.
Show PACS
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
72.80.Ey III-V and II-VI semiconductors
61.80.Fe Electron and positron radiation effects
61.82.Fk Semiconductors
61.72.S- Impurities in crystals
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)

Energy relaxation of InN thin films

D.-J. Jang, G.-T. Lin, C.-L. Wu, C.-L. Hsiao, L. W. Tu, and M.-E. Lee

Appl. Phys. Lett. 91, 092108 (2007); http://dx.doi.org/10.1063/1.2773947 (3 pages) | Cited 13 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The energy relaxation of InN thin films has been studied by ultrafast time-resolved photoluminescence technique. The obtained carrier cooling curves can be explained by carriers releasing excessive energy through the carrier–LO-phonon interaction. The extracted effective phonon emission times decrease as the photoexcited carrier concentration reduces and come close to the theoretical prediction of 23 fs at small carrier concentration. The reduction of energy loss rate at high photoexcited carrier density is attributed to the hot phonon effect.

Carrier statistics and quantum capacitance of graphene sheets and ribbons

Tian Fang, Aniruddha Konar, Huili Xing, and Debdeep Jena

Appl. Phys. Lett. 91, 092109 (2007); http://dx.doi.org/10.1063/1.2776887 (3 pages) | Cited 26 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this work, fundamental results for carrier statistics in graphene two-dimensional sheets and nanoscale ribbons are derived. Though the behavior of intrinsic carrier densities in two-dimennsional graphene sheets is found to differ drastically from traditional semiconductors, very narrow (sub-10 nm) ribbons are found to be similar to traditional narrow-gap semiconductors. The quantum capacitance, an important parameter in the electrostatic design of devices, is derived for both two-dimensional graphene sheets and nanoribbons.
Show PACS
73.63.Bd Nanocrystalline materials
72.20.-i Conductivity phenomena in semiconductors and insulators

Electronic transport in Ta2O5 resistive switch

Toshitsugu Sakamoto, Kevin Lister, Naoki Banno, Tsuyoshi Hasegawa, Kazuya Terabe, and Masakazu Aono

Appl. Phys. Lett. 91, 092110 (2007); http://dx.doi.org/10.1063/1.2777170 (3 pages) | Cited 64 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors examined the electronic transport of a solid electrolyte resistive switch. Using element analysis and the temperature dependence of its electronic transport, they deduced that the conductive path is composed of Cu metal precipitated in the solid electrolyte film by an electrochemical reaction. Furthermore, they observed Coulomb blockade phenomena at 4 K when the switch was in the off state. Their observations and experimental results suggest that the metallic conductive path consists of metallic islands separated by tunneling barriers and that switching between the on and off states originates from modulation in the tunneling barriers.
Show PACS
66.30.H- Self-diffusion and ionic conduction in nonmetals
72.80.-r Conductivity of specific materials
82.45.Gj Electrolytes
73.23.Hk Coulomb blockade; single-electron tunneling
73.40.Gk Tunneling

Spin-polarized transport in dilute magnetic semiconductor tunnel junctions

J. E. Bunder

Appl. Phys. Lett. 91, 092111 (2007); http://dx.doi.org/10.1063/1.2775032 (3 pages) | Cited 2 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The author considers transport properties of a trilayer junction consisting of an insulator sandwiched between two dilute magnetic semiconductors (DMSs). The magnetization directions of the two DMSs are not parallel but at a relative angle of θ. After calculating the transmission probabilities, the author calculates the conductance using the Landauer formula. The author defines a ratio R(θ,T), related to the tunneling magnetoresistance, which compares the θ = 0 to the θ ≠ 0 conductance at temperature T. The author also calculates R(θ,T) semiclassically using the well-known Julliere formula. The author shows that, in general, R(θ,T) obtained from the Julliere formula poorly approximates R(θ,T) obtained from the Landauer formula.
Show PACS
75.50.Pp Magnetic semiconductors
75.47.Pq Other materials
75.60.Ej Magnetization curves, hysteresis, Barkhausen and related effects

Bottom-gated metal-induced laterally crystallized silicon thin-film transistor with self-aligned raised source/drain

Il-Suk Kang, Shin-Hee Han, and Seung-Ki Joo

Appl. Phys. Lett. 91, 092112 (2007); http://dx.doi.org/10.1063/1.2778360 (3 pages) | Cited 5 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A bottom-gated metal-induced laterally crystallized silicon thin-film transistor with self-aligned raised source/drain has been fabricated and characterized. In order to achieve complete alignment of the thick source/drain to the gate, a simple process of back surface exposure was employed twice. It features a thin active channel region with fewer grains, resulting in a low grain boundary trap density and a thick source/drain region with a low lateral electric field as well as a low resistance. The proposed device simultaneously improves on the turn-on and -off currents, showing good saturation characteristics and good short-channel characteristics.
Show PACS
85.30.Tv Field effect devices

Copper-doped CdTe films with improved hole mobility

Zhixun Ma, Kin Man Yu, Lei Liu, Lan Wang, Dale L. Perry, Wladek Walukiewicz, Peter Yu, and Samuel S. Mao

Appl. Phys. Lett. 91, 092113 (2007); http://dx.doi.org/10.1063/1.2778455 (3 pages)

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Copper-doped CdTe films have been grown by the laser epitaxy approach. X-ray diffraction, Rutherford backscattering, and photoreflectance spectroscopy were utilized to characterize the CdTe:Cu films. Structural analysis suggests that the growth of CdTe:Cu on GaAs(100) is initiated along the (100) orientation, which changes to the (111) direction after the film thickness exceeds 400 nm. Hall effect measurements indicate that copper doping can achieve hole mobility over 150 cm2/V s at room temperature.
Show PACS
73.61.Ga II-VI semiconductors
81.15.Fg Pulsed laser ablation deposition
68.55.-a Thin film structure and morphology
72.20.Ee Mobility edges; hopping transport
61.72.up Other materials
78.66.Hf II-VI semiconductors

High-performance and electrically stable C60 organic field-effect transistors

X.-H. Zhang, B. Domercq, and B. Kippelen

Appl. Phys. Lett. 91, 092114 (2007); http://dx.doi.org/10.1063/1.2778472 (3 pages) | Cited 46 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report on high-performance C60 organic field-effect transistors fabricated by physical vapor deposition. Electron mobility ranging from 2.7 to 5.0 cm2/V s was achieved when treating the gate dielectric with divinyltetramethyldisiloxane bis(benzocyclobutene) and depositing C60 at room temperature. The transistors combine threshold voltages near zero, low subthreshold slopes (<0.7 V/decade), on/off current ratios larger than 106, excellent reproducibility, and good electrical stability under prolonged continuous dc bias stress.
Show PACS
85.30.Tv Field effect devices
85.65.+h Molecular electronic devices

Suppression of surface segregation and heavy arsenic doping into silicon during selective epitaxial chemical vapor deposition under atmospheric pressure

Tetsuya Ikuta, Shigeru Fujita, Hayato Iwamoto, Shingo Kadomura, Takayoshi Shimura, Heiji Watanabe, and Kiyoshi Yasutake

Appl. Phys. Lett. 91, 092115 (2007); http://dx.doi.org/10.1063/1.2778539 (3 pages) | Cited 2 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors investigated the effects of the growth rate and temperature on the surface segregation during in situ As-doped selective epitaxial growth under atmospheric pressure. It was confirmed that high growth rate and high temperature suppress surface segregation. A film with a high As concentration (7.5×1019 at./cm3) and a smooth surface was obtained by optimizing these conditions.
Show PACS
68.55.A- Nucleation and growth
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.35.Fx Diffusion; interface formation
61.72.uf Ge and Si

Study of organic thin film transistor with polymethylmethacrylate as a dielectric layer

Tsung-Syun Huang, Yan-Kuin Su, and Po-Cheng Wang

Appl. Phys. Lett. 91, 092116 (2007); http://dx.doi.org/10.1063/1.2775333 (3 pages) | Cited 33 times

Online Publication Date: 27 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The properties of pentacene-based organic thin film transistors (OTFTs) with polymethylmetha-crylate (PMMA) as a dielectric layer have been investigated. The concentration of PMMA was about 8 wt % with toluene as solvent. The pentacene film on PMMA dielectric layer displays high thin film quality according to results of x-ray diffraction scan and atomic force microscopy. The crystalline size was about 33.96 nm and the grain size was about 1000–1500 nm. The pentacene-based OTFTs with PMMA as a dielectric layer exhibited excellent electric characteristics, including a high mobility of 0.241 cm2/V s or larger, an on/off current ratio of 104 or larger, and the threshold voltage of less than −6.3 V.
Show PACS
85.30.Tv Field effect devices

Negative magnetoresistance of organic field effect transistors

Masaya Nishioka, Yeon-Bae Lee, A. M. Goldman, Yu Xia, and C. Daniel Frisbie

Appl. Phys. Lett. 91, 092117 (2007); http://dx.doi.org/10.1063/1.2775808 (3 pages) | Cited 9 times

Online Publication Date: 29 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The magnetoresistance (MR) of organic field effect transistors has been studied. Both pentacene film and tetracene single crystal devices exhibit negative MRs of up to 0.57% at 9 T. This effect has been observed between 150 and 300 K and is temperature dependent. The phenomenon may result from the action of the magnetic field on the hopping transport of carriers. However, the possibility of a magnetocapacitance effect that would increase the number of carriers cannot be ruled out.
Show PACS
85.30.Tv Field effect devices
72.20.My Galvanomagnetic and other magnetotransport effects
75.70.Ak Magnetic properties of monolayers and thin films
73.61.Ph Polymers; organic compounds

Ionized impurity scattering in n-doped C60 thin films

Kentaro Harada, Fenghong Li, Bert Maennig, Martin Pfeiffer, and Karl Leo

Appl. Phys. Lett. 91, 092118 (2007); http://dx.doi.org/10.1063/1.2776355 (3 pages) | Cited 6 times

Online Publication Date: 29 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Carrier transport in organic films is usually dominated by hopping process, leading to different temperature dependence from that of inorganic crystals. The aurhors demonstrate that n-doped C60 films show temperature dependence analogous to inorganic semiconductors. At low temperatures, the conductivity increases with temperature, around room temperature, a maximum is reached and then the conductivity decreases. These observations are confirmed by the dependence of mobility on doping level. In contrast to previous reports for organic thin films, the C60 films show a decrease of mobility with increasing doping levels, i.e., they follow the well-known Matthiessen rule which is generally observed in inorganic semiconductors.
Show PACS
73.61.Wp Fullerenes and related materials
73.50.Dn Low-field transport and mobility; piezoresistance
72.20.Ee Mobility edges; hopping transport
72.10.Fk Scattering by point defects, dislocations, surfaces, and other imperfections (including Kondo effect)
61.72.up Other materials
61.72.S- Impurities in crystals

Electronic structures of N quantum dot molecule

Shu-Shen Li and Jian-Bai Xia

Appl. Phys. Lett. 91, 092119 (2007); http://dx.doi.org/10.1063/1.2778541 (3 pages) | Cited 28 times

Online Publication Date: 29 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The electronic structures of N quantum dot molecules (QDMs) are investigated theoretically in the framework of effective-mass envelope function theory. The electron and hole energy levels are calculated. In the calculations, the effects of finite offset and valence-band mixing are taken into account. The theoretical method can be used to calculate the electronic structures of any QDM. The results show that (1) electronic energy levels decrease monotonically and the energy difference between the N QDMs decreases as the quantum dot (QD) radius increases; (2) the electron energy level is lower and quantum confinement is smaller for the larger N QDM; (3) the hole ground state energy level is lower for the one dot QDM than N (greater 1) QDMs if the QD radius is larger than about 5 nm due to the valence-band mixing. The results are useful for the application of the N QDM to photoelectric devices.
Show PACS
73.21.La Quantum dots
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor

Electrical coherent control of nuclear spins in a breakdown regime of quantum Hall effect

H. Takahashi, M. Kawamura, S. Masubuchi, K. Hamaya, T. Machida, Y. Hashimoto, and S. Katsumoto

Appl. Phys. Lett. 91, 092120 (2007); http://dx.doi.org/10.1063/1.2778465 (3 pages) | Cited 8 times

Online Publication Date: 29 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Using a conventional Hall-bar geometry with a micrometal strip on top of the surface, the authors demonstrate an electrical coherent control of nuclear spins in an AlGaAs/GaAs semiconductor heterostructure. A breakdown of integer quantum Hall (QH) effect is utilized to dynamically polarize nuclear spins. By applying a pulse rf magnetic field with the metal strip, the quantum state of the nuclear spins shows Rabi oscillations, which is detected by measuring longitudinal voltage of the QH conductor.
Show PACS
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.43.-f Quantum Hall effects

Effects of nitrogen in Stone-Wales defect on the electronic transport of carbon nanotube

Jianwei Wei, Huifang Hu, Hui Zeng, Zhiyong Wang, Lei Wang, and Ping Peng

Appl. Phys. Lett. 91, 092121 (2007); http://dx.doi.org/10.1063/1.2778544 (3 pages) | Cited 7 times

Online Publication Date: 30 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effects of nitrogen substitutional doping in Stone-Wales (SW) defect on the transport properties of single-walled nanotubes are simulated by using density functional theory and nonequilibrium Green’s functions. It is found that the nitrogen in SW produces half-filled band near the Fermi level in which the electron effective mass varies with the changing of the position of nitrogen. The total transmission coefficients nearby the Fermi level increase and the others decrease after doping. The nitrogen doping and SW defect enhance the transport property of semiconducting (8, 0) and weaken that of quasimetallic (9, 0).
Show PACS
81.07.De Nanotubes
73.22.-f Electronic structure of nanoscale materials and related systems
73.63.Fg Nanotubes
61.72.up Other materials
71.18.+y Fermi surface: calculations and measurements; effective mass, g factor
71.15.Mb Density functional theory, local density approximation, gradient and other corrections

Boron deactivation in preamorphized silicon on insulator: Efficiency of the buried oxide as an interstitial sink

J. J. Hamilton, K. J. Kirkby, N. E. B. Cowern, E. J. H. Collart, M. Bersani, D. Giubertoni, S. Gennaro, and A. Parisini

Appl. Phys. Lett. 91, 092122 (2007); http://dx.doi.org/10.1063/1.2778749 (3 pages) | Cited 3 times

Online Publication Date: 30 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Preamorphization of ultrashallow implanted boron in silicon on insulator is optimized to produce an abrupt boxlike doping profile with negligible electrical deactivation and significantly reduced transient enhanced diffusion. The effect is achieved by positioning the as-implanted amorphous/crystalline interface close to the buried oxide interface to minimize interstitials while leaving a single-crystal seed to support solid-phase epitaxy. Results support the idea that the interface between the Si overlayer and the buried oxide is an efficient interstitial sink.
Show PACS
61.72.up Other materials
61.72.S- Impurities in crystals
66.30.H- Self-diffusion and ionic conduction in nonmetals
61.72.J- Point defects and defect clusters

CuBO2: A p-type transparent oxide

Michael Snure and Ashutosh Tiwari

Appl. Phys. Lett. 91, 092123 (2007); http://dx.doi.org/10.1063/1.2778755 (3 pages) | Cited 25 times

Online Publication Date: 30 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The authors report the synthesis of CuBO2, a p-type transparent oxide belonging to Cu-delafossite family. High quality thin films of CuBO2 were deposited on c-plane sapphire substrates by pulsed laser deposition technique. Detailed structural, optical, and electrical characterizations on these films were performed. Optical transmission measurement showed the films to be highly transparent in the visible range and having indirect and direct band gaps of 2.2 and 4.5 eV, respectively. Room-temperature electrical conductivity of CuBO2 films was 1.65 S cm−1 and exhibited semiconductorlike temperature dependence. The Hall and Seebeck coefficients of the film were positive, indicating the p-type nature of the material.
Show PACS
72.20.My Galvanomagnetic and other magnetotransport effects
73.50.Lw Thermoelectric effects
73.61.Le Other inorganic semiconductors
78.66.Li Other semiconductors
81.15.Fg Pulsed laser ablation deposition
68.55.A- Nucleation and growth
68.55.-a Thin film structure and morphology

In situ electrical impedance spectroscopy under high pressure on diamond anvil cell

Chunyuan He, Chunxiao Gao, Yanzhang Ma, Ming Li, Aimin Hao, Xiaowei Huang, Bingguo Liu, Dongmei Zhang, Cuiling Yu, Guangtian Zou, Yanchun Li, Hui Li, Xiaodong Li, and Jing Liu

Appl. Phys. Lett. 91, 092124 (2007); http://dx.doi.org/10.1063/1.2778760 (3 pages) | Cited 6 times

Online Publication Date: 30 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The effect of grain boundary on electrical transportation properties is a basic physical problem and also a subject of material science and technology. In situ electrical measurement of powdered materials under high pressure provides a chance to figure out the electrical properties of grain boundaries. In this letter, the authors report an in situ impedance spectroscopy method used in conjunction with a diamond anvil cell for electrical property research of grain boundaries under high pressure. Powdered CdS was pressed up to 23 GPa and an impedance arc corresponding to the grain boundary was detected. It was found that the electrical property of the grain boundary changed with pressure and could be determined by the resistance and the relaxation frequency. Pressure decreases the effective scattering section of the grain boundary to charge carriers, and finally leads to the decrease of resistance and activation energy of the grain boundary.
Show PACS
61.72.Mm Grain and twin boundaries
62.50.-p High-pressure effects in solids and liquids
72.80.Ey III-V and II-VI semiconductors

Misoriented domains in (0001)-GaN/(111)-Ge grown by molecular beam epitaxy

Y. Zhang, C. McAleese, H. Xiu, C. J. Humphreys, R. R. Lieten, B. Degroote, and G. Borghs

Appl. Phys. Lett. 91, 092125 (2007); http://dx.doi.org/10.1063/1.2779099 (2 pages) | Cited 5 times

Online Publication Date: 30 August 2007

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Structural characterization has been performed on (0001)-GaN epilayers grown on (111)-Ge substrates using plasma assisted molecular beam epitaxy. By combining high-resolution x-ray diffraction, transmission electron microscopy, and scanning transmission electron microscopy, it has been shown that the GaN epilayer consists of misoriented domains. The domains are rotated about the GaN-[0001] (Ge-[111]) zone axis by 8° with respect to each other and by ±4° with respect to the Ge substrate. These domains need to be eliminated to reduce grain boundary defects and improve GaN crystal quality.
Show PACS
68.60.Wm Other nonelectronic physical properties
61.72.Mm Grain and twin boundaries
Page 1 of 2 Pages Return to All Sections Next Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close