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21 Nov 1994

Volume 65, Issue 21, pp. 2627-2745

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Prospects for truly blue ZnSe/Zn1−uMguSvSe1−v/Zn1−xMgxSy Se1−y semiconductor diode lasers

P. M. Mensz

Appl. Phys. Lett. 65, 2627 (1994); http://dx.doi.org/10.1063/1.113032 (3 pages) | Cited 9 times

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The electrical and optical operation of separate confinement heterostructure quantum‐well lasers of ZnSe/Zn1−uMguSvSe1−v/Zn1−xMgxSy Se1−y (blue laser) and Zn0.8Cd0.2Se/ZnS0.06Se0.94/ Zn1−zMgzSuSe1−u (blue‐green laser) was studied by numerical simulation. The physical model was based on the self‐consistent solution of Poisson’s equation, the current continuity equation, the photon rate equation, and the scalar wave equation. The band structure of strained quantum well was calculated using k⋅p theory, and the gain model was based on the interband electron‐hole pair recombination without including excitonic effects. Good agreement was obtained between the experimental and the calculated output characteristics of Zn0.8Cd0.2Se/ZnSe0.06Se0.94/ Zn1−zMgzSuSe1−u blue‐green lasers over a wide temperature range from 85 to 394 K. Further extension of these calculations to the ZnSe/Zn1−uMguSvSe1−v/Zn1−xMgxSy Se1−y structures demonstrated a considerable increase in threshold current density of blue lasers, due to the insufficient level of doping in wide‐band p‐Zn1−xMgxSySe1−y cladding layers. This would likely impose more stringent conditions for realization of continuous blue laser emission compared to their blue‐green laser counterparts. © 1994 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
42.60.-v Laser optical systems: design and operation
78.66.Hf II-VI semiconductors

Short wavelength (5.36–1.85 μm) nonlinear spectroscopy of coupled InGaAs/AlAs intersubband quantum wells

E. L. Martinet, H. C. Chui, G. L. Woods, M. M. Fejer, J. S. Harris, C. A. Rella, B. A. Richman, and H. A. Schwettman

Appl. Phys. Lett. 65, 2630 (1994); http://dx.doi.org/10.1063/1.112585 (3 pages) | Cited 5 times

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We report short wavelength second‐harmonic generation (SHG) spectroscopy of asymmetric coupled In0.6Ga0.4As/AlAs quantum wells (QWs). The QW is designed to show maximum second‐order nonlinear susceptibility χ(2) for SHG of 4 and 2 μm wavelengths by single and double resonance effects, respectively. SHG spectroscopy across the midinfrared is measured using both a CO2 and a free electron laser as pumps. The χ(2) of the QW is extracted from interference of the second‐harmonic fields from the QW and GaAs substrate, determined by the azimuthal dependence of the SHG power. We measure χ(2) of the QW for harmonic wavelengths between 5.36 and 1.85 μm. This is the shortest wavelength SHG to date by any QW intersubband interaction. Good agreement of experiment with theory for the dispersion of χ(2) for both singly and doubly resonant conversion is observed throughout the midinfrared. © 1994 American Institute of Physics.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
78.66.Fd III-V semiconductors

4.3 terahertz four‐wave mixing spectroscopy of InGaAsP semiconductor amplfiers

A. D’Ottavi, E. Iannone, A. Mecozzi, S. Scotti, P. Spano, R. Dall’Ara, G. Guekos, and J. Eckner

Appl. Phys. Lett. 65, 2633 (1994); http://dx.doi.org/10.1063/1.112586 (3 pages) | Cited 29 times

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A four‐wave mixing experiment in a bulk InGaAsP traveling‐wave semiconductor amplifier is reported. The maximum pump‐probe detuning is 4.3 THz. The equivalent time resolution of 37 fs is high enough to measure with good accuracy the time constant of spectral‐hole burning (100 fs in our case). The simultaneous presence of spectral‐hole burning and of an instantaneous, within our time resolution, saturation process is clearly displayed.  
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78.47.-p Spectroscopy of solid state dynamics
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
42.55.Px Semiconductor lasers; laser diodes

Conjugated polymer light‐emitting diodes on silicon substrates

D. R. Baigent, R. N. Marks, N. C. Greenham, R. H. Friend, S. C. Moratti, and A. B. Holmes

Appl. Phys. Lett. 65, 2636 (1994); http://dx.doi.org/10.1063/1.112587 (3 pages) | Cited 48 times

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We report the fabrication of polymer electroluminescent devices on doped silicon substrates. An electron‐injecting aluminum electrode is thermally evaporated onto the silicon substrate, and a layer of a high electron affinity conjugated polymer, poly(cyanoterephthalylidene), CN‐PPV, is then spin coated onto this. A hole‐transporting layer of poly(p‐phenylene vinylene), PPV, is formed on top of the CN‐PPV layer by thermal conversion of a spin‐coated layer of the sulphonium precursor polymer. Finally, a transparent hole‐injecting top electrode of indium‐tin oxide is formed by rf sputtering. These devices show efficient red electroluminescence, with emission from the CN‐PPV layer. © 1994 American Institute of Physics.
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85.60.Jb Light-emitting devices
78.60.Fi Electroluminescence
78.66.Qn Polymers; organic compounds

Periodic cladding surface structures induced when recording fiber Bragg reflectors with a single pulse from a KrF excimer laser

S. J. Mihailov and M. C. Gower

Appl. Phys. Lett. 65, 2639 (1994); http://dx.doi.org/10.1063/1.112588 (3 pages) | Cited 3 times

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Observations are presented of ∼1 μm deep periodic structures on the cladding surface of optical fibers which are simultaneously induced when recording first‐order fiber Bragg reflectors by single pulse KrF excimer laser holographic exposure. © 1994 American Institute of Physics.
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42.81.-i Fiber optics
42.40.Eq Holographic optical elements; holographic gratings
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)

Improved mode stability in low threshold single quantum well native‐oxide defined vertical‐cavity lasers

D. L. Huffaker, J. Shin, H. Deng, C. C. Lin, D. G. Deppe, and B. G. Streetman

Appl. Phys. Lett. 65, 2642 (1994); http://dx.doi.org/10.1063/1.112589 (3 pages) | Cited 8 times

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Single quantum well active region vertical‐cavity surface‐emitting lasers (VCSELs) fabricated using a ‘‘native‐oxide’’ technique are compared with three quantum well active region VCSELs. The single quantum well active region exhibits improved transverse mode stability under a variety of operating conditions. The suggested reason is due to the reduced gain of the single quantum well, which results in greater lasing mode selectivity. For the single quantum well active region, a continuous wave threshold current of 178 μA at room temperature is measured for a 5 μm diam VCSEL and a pulsed threshold of 160 μA. © 1994 American Institute of Physics.
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42.55.Px Semiconductor lasers; laser diodes
42.60.-v Laser optical systems: design and operation

Optically multistable operation of a waveguide device based on the Wannier–Stark effect in an InGaAs/InP superlattice

H. C. Neitzert, D. Campi, C. Cacciatore, C. Rigo, A. Stano, and C. Coriasso

Appl. Phys. Lett. 65, 2645 (1994); http://dx.doi.org/10.1063/1.112590 (3 pages) | Cited 3 times

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An optically multistable device in waveguide configuration has been fabricated, which is based on the Wannier–Stark effect in an InGaAs/InP superlattice. It implements a waveguided version of the self‐electro‐optic effect device and it operates at room temperature at a wavelength of 1.55 μm. © 1994 American Institute of Physics.  
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42.82.Et Waveguides, couplers, and arrays
42.65.Pc Optical bistability, multistability, and switching, including local field effects
78.66.Fd III-V semiconductors

Two photon absorption of di‐alkyl‐amino‐nitro‐stilbene side chain polymer

M. Cha, W. E. Torruellas, G. I. Stegeman, W. H. G. Horsthuis, G. R. Möhlmann, and J. Meth

Appl. Phys. Lett. 65, 2648 (1994); http://dx.doi.org/10.1063/1.112591 (3 pages) | Cited 50 times

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The two photon absorption spectrum has been measured in the 780–1600 nm range for a di‐alkyl‐amino‐nitro‐stilbene side‐chain polymer. A single two photon peak centered at 920 nm is observed with a peak two photon coefficient of 5.5 cm/GW. Bleaching via two photon absorption at this wavelength is investigated by measuring a refractive index change after an intensive exposure. © 1994 American Institute of Physics.
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78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
78.66.Qn Polymers; organic compounds
42.65.-k Nonlinear optics
42.70.Jk Polymers and organics

Improved poling and thermal stability of sol‐gel nonlinear optical polymers

Srinath Kalluri, Yongqiang Shi, William H. Steier, Zhixin Yang, Chengzeng Xu, Bo Wu, and Larry R. Dalton

Appl. Phys. Lett. 65, 2651 (1994); http://dx.doi.org/10.1063/1.112592 (3 pages) | Cited 10 times

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An aminosulfone dye chromophore was covalently incorporated into a sol‐gel network for second‐order nonlinear optics applications by functionalizing both ends of the chromophore. Covalent incorporation allows for high chromophore loading densities (∼35%) and locking in both ends of the chromophore improves thermal stability. Short term stability of the nonlinearity at 200 °C and long term stability over 500 h at 100 °C was demonstrated. Two different temperature profiles for corona poling were investigated and one found superior to the other. A second harmonic coefficient, d33 of 27 pm/V at the 1064 nm fundamental wavelength was measured. © 1994 American Institute of Physics.
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42.70.Jk Polymers and organics
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation

Near-field photoconductivity: Application to carrier transport in InGaAsP quantum well lasers

S. K. Buratto, J. W. P. Hsu, E. Betzig, J. K. Trautman, R. B. Bylsma, C. C. Bahr, and M. J. Cardillo

Appl. Phys. Lett. 65, 2654 (1994); http://dx.doi.org/10.1063/1.112593 (3 pages) | Cited 35 times

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A new contrast method in near-field scanning optical microscopy in which the near-field probe is used to excite photocurrent in a semiconductor sample is described and demonstrated. The use of near-field optics results in an order-of-magnitude improvement in spot size and a fivefold improvement in resolution over previous methods of photocurrent imaging. The application of this near-field photoconductivity technique to a multiquantum well laser provides direct visualization of carrier transport throughout the structure, yielding information on growth inhomogeneities, carrier leakage and isolation, and the overall quality of p-n junctions. © 1994 American Institute of Physics.
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07.60.Pb Conventional optical microscopes
85.30.De Semiconductor-device characterization, design, and modeling
42.55.Px Semiconductor lasers; laser diodes
72.40.+w Photoconduction and photovoltaic effects

Bias dependent recovery time of all‐optical resonant nonlinearity in an InGaAsP/InGaAsP multiquantum well waveguide

I. E. Day, P. A. Snow, R. V. Penty, I. H. White, R. S. Grant, G. T. Kennedy, W. Sibbett, D. A. O. Davies, M. A. Fisher, and M. J. Adams

Appl. Phys. Lett. 65, 2657 (1994); http://dx.doi.org/10.1063/1.112594 (3 pages) | Cited 3 times

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The refractive nonlinearities due to bandfilling and the plasma effect in a multiquantum well buried heterostructure semiconductor waveguide under reverse bias are probed using self‐phase modulation techniques. Modeling of the self‐phase modulation has allowed the magnitude of the phase modulation and nonlinearity recovery time constant to be extracted. π radians phase shift has been obtained for a coupled pulse energy of 32 pJ. The nonlinearity recovery time constant is 18±3 ps for an applied field of 34 MV m−1, limited by thermionic emission from the quantum wells. © 1994 American Institute of Physics.
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42.65.Pc Optical bistability, multistability, and switching, including local field effects
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.79.Hp Optical processors, correlators, and modulators

Photoemission studies with barium and LaB6 photocathodes and polarized laser light

M. E. Conde, S. I. Kwon, A. T. Young, K.N. Leung, and K.‐J. Kim

Appl. Phys. Lett. 65, 2660 (1994); http://dx.doi.org/10.1063/1.112993 (3 pages) | Cited 1 time

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Photoemission measurements with barium and single crystal LaB6 photocathodes are reported. The barium cathode is prepared by depositing a barium thin film onto a copper substrate. The LaB6 cathode is a single crystal cut in the 〈100〉 plane. Radiation from a nitrogen laser (337 nm, 10 ns) is polarized and strikes the cathode surface at variable angles. An electron quantum yield as high as 2×10−3 is observed with barium. The dependence of the quantum yield on the beam polarization and angle of incidence is investigated. The results indicate that higher quantum yields are achieved when the angles of polarization and incidence are such as to minimize the reflection coefficient. © 1994 American Institute of Physics.
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79.60.-i Photoemission and photoelectron spectra
85.60.Ha Photomultipliers; phototubes and photocathodes
07.77.-n Atomic, molecular, and charged-particle sources and detectors
41.75.Fr Electron and positron beams

Photopyroelectric study of nonlinear heat transport phenomena at a liquid crystal phase transition

M. Marinelli, F. Mercuri, U. Zammit, and V. Gusev

Appl. Phys. Lett. 65, 2663 (1994); http://dx.doi.org/10.1063/1.112595 (3 pages) | Cited 6 times

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A front detection photopyroelectric configuration has been used to study the nonlinear heat transport processes that take place in the vicinity of the smectic A–nematic phase transition of the 9 CB liquid crystal. An increase in the sensitivity of this technique with respect to other photothermal techniques as far as the phase transition detection is concerned has been obtained. © 1994 American Institute of Physics.
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61.30.-v Liquid crystals
66.25.+g Thermal conduction in nonmetallic liquids
78.20.hb Piezo-optical, elasto-optical, acousto-optical, and photoelastic effects
78.20.N- Thermo-optic effects
78.20.nb Photothermal effects

Formation mechanism of TiC by mechanical alloying

Z. G. Liu, J. T. Guo, L. L. Ye, G. S. Li, and Z. Q. Hu

Appl. Phys. Lett. 65, 2666 (1994); http://dx.doi.org/10.1063/1.112596 (3 pages) | Cited 39 times

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Titanium carbide (TiC) has been synthesized by mechanically alloying the elemental powder mixture of titanium and graphite at composition of Ti1−xCx (x=0.35, 0.43, 0.50). Under the employed milling condition, the formation of TiC has been found to undergo an abrupt, exothermic reaction. The final product is TiC for x=0.43 and 0.50, and TiC+Ti (small amount) for x=0.35. It is suggested that this reaction appears to be a self‐sustained high‐temperature synthesis process. The initial milling stage seems to be an incubation duration for the reaction, and the mechanical impacts to be the ignition of the following abrupt reaction. It is believed that this type of reaction is an important mechanism for mechanical alloying of the highly exothermic alloy systems. © 1994 American Institute of Physics.
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81.20.Ev Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation

Textured growth of cubic boron nitride film on nickel substrates

Zhizhong Song, Fangqing Zhang, Yongping Guo, and Guanghua Chen

Appl. Phys. Lett. 65, 2669 (1994); http://dx.doi.org/10.1063/1.112597 (3 pages) | Cited 12 times

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Textured cubic boron nitride (c‐BN) films have been deposited on (220) oriented crystallized polycrystalline nickel substrate by a hot filament assisted rf plasma chemical vapor deposition method. X‐ray diffraction shows that the films are (220) preferentially grown, the peak ratio of (220) to the main peak [i.e., the (111) peak] is about 5.2. The scanning electron microscopy images exhibit regular grain shapes. Most of the grains are rectangular, also indicating the (220) growth. The grain size is about 5 μm. The well‐matched Ni lattice with c‐BN, the catalytic effect of Ni, and the appropriate rf bias are considered to be the key factors in the textured growth. © 1994 American Institute of Physics.  
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
68.55.-a Thin film structure and morphology

Hard boron oxide thin‐film deposition using electron cyclotron resonance microwave plasmas

S. M. Gorbatkin, R. L. Rhoades, T. Y. Tsui, and W. C. Oliver

Appl. Phys. Lett. 65, 2672 (1994); http://dx.doi.org/10.1063/1.112598 (3 pages) | Cited 21 times

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Hard boron suboxide thin films were deposited in an electron cyclotron resonance (ECR) microwave plasma system at substrate temperatures below 300 °C. A high‐temperature effusion cell, operated at 2200°–2250 °C, was used for injection of boron downstream of an Ar/O2 ECR plasma. B ion bombardment is estimated to have been up to 6% of the total boron flux, and Ar ion bombardment is estimated to have contributed ∼100 eV/deposited atom. Boron suboxide films with oxygen concentrations of 11% exhibited hardnesses up to 30 GPa, equal to sapphire and near that of pure boron. The hardness/modulus ratio was 0.1, significantly better than that of sapphire (0.067) or solid boron (0.074), indicating these films may be of interest for a variety of tribological applications. © 1994 American Institute of Physics.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
68.60.-p Physical properties of thin films, nonelectronic

Anisotropy in diamond etching with molten cerium

S. Jin, W. Zhu, T. Siegrist, T. H. Tiefel, G. W. Kammlott, J. E. Graebner, and M. McCormack

Appl. Phys. Lett. 65, 2675 (1994); http://dx.doi.org/10.1063/1.112599 (3 pages) | Cited 2 times

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An orientation‐dependent etching behavior has been observed during diffusional thinning of single crystal diamond by molten cerium. The etching rate at 920 °C was in the order of {111}≳{100}≳{110} with a relative ratio of about 5:2:1. This diamond etching anisotropy is tentatively attributed to the orientation‐dependent difference in the energy required to break the bonds on each atomic plane. It is interesting to note that the easiest‐etching plane found here, {111}, is the most difficult plane to polish mechanically, and the most difficult plane to etch, {110}, is the easiest plane for mechanical polishing. © 1994 American Institute of Physics.
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81.65.-b Surface treatments

Lead loss, preferred orientation, and the dielectric properties of sol‐gel prepared lead titanate thin films

Eiichi Sato, Yuhong Huang, Marija Kosec, Andrew Bell, and Nava Setter

Appl. Phys. Lett. 65, 2678 (1994); http://dx.doi.org/10.1063/1.112600 (3 pages) | Cited 15 times

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The PbO loss during rapid thermal annealing of PbTiO3 thin films prepared by the sol‐gel method has been investigated using electron probe microanalysis. The results have been correlated with the x‐ray diffraction analyses and the dielectric properties of the films. The films start to loose PbO significantly during annealing at 600 °C for 60 s. After annealing at 700 °C the Pb/Ti ratios decrease down to 1.0 independent of the amount of excess PbO of the solutions. No PbO crystalline phases are observed in the x‐ray diffraction patterns, therefore the excess PbO is assumed to remain in the films as an amorphous phase. © 1994 American Institute of Physics.
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81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.70.+a Pyroelectric and electrocaloric effects

Stability of magnetic field‐induced dipolar order in a ferroelectric side‐chain liquid crystal polymer

S. Sprunt, G. Nounesis, J. Naciri, B. R. Ratna, and R. Shashidhar

Appl. Phys. Lett. 65, 2681 (1994); http://dx.doi.org/10.1063/1.112601 (3 pages) | Cited 1 time

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The stability of in‐layer dipolar order in a side‐chain ferroelectric liquid crystalline polymer has been investigated by probing the optical birefringence produced by aligning the mesogenic side groups with a high magnetic field. The temperature dependence of the decay time associated with the mesogen relaxation from a state of saturated alignment obeys an Arrhenius law, with an activation energy two to three times higher than the typical value for low molecular weight liquid crystals. The exponent characterizing the relaxation process is found to be temperature‐dependent in the ferroelectric smectic‐C∗ phase, and approaches unity near the polymer glass transition. The implications of these results for nonlinear‐optics applications are discussed. © 1994 American Institute of Physics.
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61.30.Gd Orientational order of liquid crystals; electric and magnetic field effects on order
42.70.Df Liquid crystals

Light emission from thermally oxidized silicon nanoparticles

D. Zhang, R. M. Kolbas, P. D. Milewski, D. J. Lichtenwalner, A. I. Kingon, and J. M. Zavada

Appl. Phys. Lett. 65, 2684 (1994); http://dx.doi.org/10.1063/1.112602 (3 pages) | Cited 23 times

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Light emission characteristics from silicon nanoparticles consisting of a crystalline core encased in an amorphous oxide shell are presented. The particles were thermally oxidized in the open atmosphere at 800 °C for times from 5 to 160 min in order to decrease the Si core dimensions. Photoluminescence spectra, at low excitation levels, reveal that the light emission shifts to shorter wavelengths as the oxidation time is increased. At high excitation levels, photoluminescence spectra show little or no shift. These results indicate that there are at least two mechanisms involved with light emission from Si nanoparticles, one associated with quantum size effects and another which is independent of size distribution. © 1994 American Institute of Physics.
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78.55.Hx Other solid inorganic materials
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing
85.35.-p Nanoelectronic devices
81.65.-b Surface treatments
61.46.-w Structure of nanoscale materials

Possible lifetime‐limiting defect in 6H SiC

N. T. Son, E. Sörman, W. M. Chen, O. Kordina, B. Monemar, and E. Janzén

Appl. Phys. Lett. 65, 2687 (1994); http://dx.doi.org/10.1063/1.112962 (3 pages) | Cited 19 times

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We reveal and investigate a possible lifetime‐limiting defect in as‐grown 6H SiC by optical detection of magnetic resonance (ODMR). This defect is shown to be a deep level center (with an energy level at about Ec−1.1 eV), evident from the related deep photoluminescence emission and a photo‐excitation spectrum of the ODMR signal. The fact that this defect has been observed in both bulk crystals and epilayers, regardless of their doping type, indicates that this must be a common and basic defect in 6H SiC. © 1994 American Institute of Physics.
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71.55.Ht Other nonmetals
61.72.Hh Indirect evidence of dislocations and other defects (resistivity, slip, creep, strains, internal friction, EPR, NMR, etc.)
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping

Thermoelectric figure of merit of superlattices

J. O. Sofo and G. D. Mahan

Appl. Phys. Lett. 65, 2690 (1994); http://dx.doi.org/10.1063/1.112607 (3 pages) | Cited 68 times

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We calculate the electrical conductivity, thermopower, and the electronic contribution to the thermal conductivity of a superlattice, with the electric field and the thermal gradient applied parallel to the interfaces. We include the tunneling between quantum wells. The broadening of the lowest subband when the period of the superlattice is decreased produces a reduction of the thermoelectric figure of merit. However, we found that a moderate increase of the figure of merit may be expected for intermediate values of the period, due to the enhancement of the density of states produced by the superlattice structure. © 1994 American Institute of Physics.
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73.50.Lw Thermoelectric effects
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.40.Gk Tunneling
85.80.Fi Thermoelectric devices

Synthesis of epitaxial Pt on (100)Si using TiN buffer layer by pulsed laser deposition

P. Tiwari, X. D. Wu, S. R. Foltyn, Q. X. Jia, I. H. Campbell, P. A. Arendt, R. E. Muenchausen, D. E. Peterson, T. E. Mitchell, and J. Narayan

Appl. Phys. Lett. 65, 2693 (1994); http://dx.doi.org/10.1063/1.112608 (3 pages) | Cited 7 times

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High‐quality epitaxial Pt films were deposited by pulsed laser deposition on (100)Si using TiN as a buffer layer. The films were (100) oriented normal to the substrate surface with a high degree of in‐plane orientation with respect to the major axes of the substrate and buffer layer. An ion beam minimum channeling yield of 39% was obtained for the Pt films, indicating high crystallinity. High‐resolution transmission electron microscopy results showed that interfaces between substrate/film and film/film were quite smooth and no perceptible interdiffusion was observed. The epitaxial TiN layer effectively acts as a barrier to impede metal‐substrate reaction and helps in good adhesion of the Pt films on (100)Si. This structure is suitable for epitaxial growth of oxide films on Si with an underlying conductive electrode. © 1994 American Institute of Physics.
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68.55.-a Thin film structure and morphology
85.40.Ls Metallization, contacts, interconnects; device isolation
81.15.Fg Pulsed laser ablation deposition

Defect generation and suppression during the impurity‐induced layer disordering of quantum‐sized GaAs/GaInP layers

R. L. Thornton, D. P. Bour, D. Treat, F. A. Ponce, J. C. Tramontana, and F. J. Endicott

Appl. Phys. Lett. 65, 2696 (1994); http://dx.doi.org/10.1063/1.112609 (3 pages) | Cited 3 times

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We have investigated both analytically and experimentally the mechanisms for defect formation during interdiffusion of GaAs and GaInP. We find that the analytical model predicts a critical thickness below which defects are not produced during this highly strained interdiffusion process. Transmission electron microscopy analysis of diffused buried layers of varying thickness exhibits very good qualitative agreement with the analysis developed. © 1994 American Institute of Physics.
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68.35.Fx Diffusion; interface formation
61.72.Ff Direct observation of dislocations and other defects (etch pits, decoration, electron microscopy, x-ray topography, etc.)
71.55.Eq III-V semiconductors
61.80.Jh Ion radiation effects

Electrical properties and formation mechanism of porous silicon carbide

A. O. Konstantinov, C. I. Harris, and E. Janzén

Appl. Phys. Lett. 65, 2699 (1994); http://dx.doi.org/10.1063/1.112610 (3 pages) | Cited 55 times

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Variation of the preparation conditions of porous silicon carbide is shown to have a strong effect on the structural and electrical properties of the material obtained. A correlation has been observed between the fiber size and resistivity of porous SiC, a decrease of fiber size results in a semi‐insulating material due to Fermi‐level pinning to surface states. A model is proposed for the mechanism of fiber size self‐regulation responsible for the porous material formation. The model relates the blocking of the fiber dissolution process to the increase of resistivity in a thin fiber due to Fermi‐level pinning. We suggest that the Fermi‐level pinning model is also applicable to the formation mechanism of porous silicon. © 1994 American Institute of Physics.
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81.65.-b Surface treatments
82.45.-h Electrochemistry and electrophoresis
81.07.-b Nanoscale materials and structures: fabrication and characterization
81.16.-c Methods of micro- and nanofabrication and processing
85.35.-p Nanoelectronic devices
73.30.+y Surface double layers, Schottky barriers, and work functions
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