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7 May 1990

Volume 56, Issue 19, pp. 1819-1921

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Type II phase matching in a β‐barium borate optical parametric oscillator

W. R. Bosenberg and C. L. Tang

Appl. Phys. Lett. 56, 1819 (1990); http://dx.doi.org/10.1063/1.103080 (3 pages) | Cited 12 times

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We report the first demonstration of a type II phase‐matched optical parametric oscillator using β‐barium borate (BBO) as the nonlinear optical material. The optical parametric oscillator (OPO) is pumped at 354.7 nm and tuning has been demonstrated over 0.48–0.63 μm and 0.81–1.36 μm. The linewidth of the device, without line narrowing elements, is 0.5–3.0 Å, which is dramatically narrower than that of a corresponding type I phase‐matched BBO OPO. Experimentally usable conversion efficiencies of 12% have been achieved.
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42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
07.60.-j Optical instruments and equipment
42.79.-e Optical elements, devices, and systems

Giant nonlinear optical rectification at 8–12 μm in asymmetric coupled quantum wells

E. Rosencher, Ph. Bois, B. Vinter, J. Nagle, and D. Kaplan

Appl. Phys. Lett. 56, 1822 (1990); http://dx.doi.org/10.1063/1.103081 (3 pages) | Cited 43 times

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We report giant, nonlinear optical rectification in asymmetric quantum wells weakly coupled by an intermediate potential barrier. This phenomenon originates from (i) macroscopic displacements (30 nm) of carriers during optical transitions and (ii) large storage times of excited electrons because of a slow transfer mechanism between the wells (≊6 ps at 77 K). The resulting rectification coefficient is 1.62×10−3 m/V per well, more than six orders of magnitude higher than in bulk GaAs. These structures really behave as giant ‘‘quasimolecules’’ optimized for infrared optical nonlinearities and their use may be envisioned for a new class of infrared detectors.
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73.50.Pz Photoconduction and photovoltaic effects
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors
85.60.Gz Photodetectors (including infrared and CCD detectors)

Threshold current reduction in patterned quantum well semiconductor lasers grown by molecular beam epitaxy

E. Kapon, S. Simhony, J. P. Harbison, L. T. Florez, and P. Worland

Appl. Phys. Lett. 56, 1825 (1990); http://dx.doi.org/10.1063/1.103196 (3 pages) | Cited 15 times

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Reduction of threshold current in GaAs/AlGaAs patterned quantum well (PQW) lasers grown by molecular beam epitaxy is studied. Application of high reflection coating results in threshold currents as low as 0.35 mA. Dependence of the measured threshold currents on the optical cavity losses agrees well with a simple model accounting for gain saturation in the quantum well active region. It is shown that gain saturation and finite optical confinement in the lateral direction lead to a minimum in the threshold current for an optimal width of the optical waveguide. Threshold currents as low as ∼100 μA are predicted for PQW lasers with ∼0.2‐μm‐wide active regions.
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42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.79.Sz Optical communication systems, multiplexers, and demultiplexers
42.82.-m Integrated optics

Current confinement in a GaAs/AlGaAs heterostructure by in situ laser‐patterned desorption of a current‐blocking quantum well

J. E. Epler, D. W. Treat, and T. L. Paoli

Appl. Phys. Lett. 56, 1828 (1990); http://dx.doi.org/10.1063/1.103082 (3 pages)

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Radiation from Ar+ and Nd:YAG lasers is used within a metalorganic chemical vapor deposition reactor to thermally desorb selected areas of GaAs quantum well (QW) layers during a pause in the epitaxial growth. The process, called laser‐patterned desorption, is used to laterally pattern current confinement in an AlGaAs/GaAs diode laser structure. Current channels are produced by completely removing selected areas (∼3 mm wide) of an n+ GaAs QW blocking layer embedded in the AlGaAs p cladding of a separate confinement heterostructure laser. Scanning electron microscopy cross sections indicate the blocking layer is completely removed in regions illuminated with the focused laser beam. Current confinement is confirmed by observing the localized optical emission from a 1‐cm‐long bar containing a 1‐mm‐wide desorbed region. Broad‐area diode lasers fabricated from the sample exhibit a forward voltage varying from a minimum (∼2 V) within the lase‐desorbed region to a maximum (∼4 V) in the surrounding field. This work is the first demonstration of current confinement produced by epitaxial patterning in an optical device during growth.
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42.55.Px Semiconductor lasers; laser diodes
85.30.Kk Junction diodes
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)

Thermal modeling of continuous‐wave end‐pumped solid‐state lasers

M. E. Innocenzi, H. T. Yura, C. L. Fincher, and R. A. Fields

Appl. Phys. Lett. 56, 1831 (1990); http://dx.doi.org/10.1063/1.103083 (3 pages) | Cited 141 times

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In order to estimate deleterious effects caused by heating in continuous‐wave end‐pumped solid‐state lasers, the heat equation has been solved for an axially heated cylinder with a thermally conductive boundary at the periphery. Steady‐state thermal profiles are developed using both a full numerical solution and an analytic approximation which assumes only radial heat flow. The analytic solution, which is in good agreement with the numerical solution, is utilized to obtain an expression for the thermal focusing due to temperature‐induced refractive index changes. For Nd:YAG, 1 W of pump power deposited as heat is predicted to cause a thermal focusing length comparable to the cavity length of a typical diode end‐pumped laser.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.-f Lasers
42.60.By Design of specific laser systems
44.90.+c Other topics in heat transfer (restricted to new topics in section 44)

Femtosecond dynamics of the nonlinear index near the band edge in AlGaAs waveguides

K. K. Anderson, M. J. LaGasse, C. A. Wang, J. G. Fujimoto, and H. A. Haus

Appl. Phys. Lett. 56, 1834 (1990); http://dx.doi.org/10.1063/1.103061 (3 pages) | Cited 14 times

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The transient behavior of the nonresonant nonlinear index is investigated in AlGaAs waveguides with femtosecond time resolution. Both the refractive index and the absorption changes are measured by time division interferometry and pump probe techniques. Different mechanisms which contribute to the nonlinear index are distinguished by examining their dynamics, including the optical Stark effect, resonantly excited carriers, and two‐photon absorption processes. The relative contribution from each mechanism is a strong function of wavelength near the band edge.
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42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.79.Gn Optical waveguides and couplers
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)

Complete single‐mode continuous‐wave operation in 180° mode AlGaAs phased array lasers with dummy stripes

M. Sagawa and T. Kajimura

Appl. Phys. Lett. 56, 1837 (1990); http://dx.doi.org/10.1063/1.103062 (2 pages) | Cited 3 times

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A new AlGaAs phased array laser structure with dummy stripes outside the stripe region is developed. The dummy stripes are dashed line stripes along both edge elements of the array stripes. Therefore, current in these dummy stripes does not cause lasing, but does increase the temperature of the edge elements. Thermal distribution in the array stripes, which mainly causes multimode oscillation in phased array lasers, is effectively unified by the dummy stripes. As a result, completely single lateral 180° mode continuous‐wave operation is realized for the first time in this novel phased array laser.
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42.55.Px Semiconductor lasers; laser diodes
42.60.By Design of specific laser systems
42.60.Fc Modulation, tuning, and mode locking
85.60.Jb Light-emitting devices

Submilliampere continuous‐wave room‐temperature lasing operation of a GaAs mushroom structure surface‐emitting laser

Ying Jay Yang, Thaddeus G. Dziura, S. C. Wang, Wei Hsin, and Shyh Wang

Appl. Phys. Lett. 56, 1839 (1990); http://dx.doi.org/10.1063/1.103063 (2 pages) | Cited 5 times

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We report a GaAs mushroom structure surface‐emitting laser at 900 nm with submilliampere (0.2–0.5 mA) threshold under room‐temperature cw operation for the first time. The very low threshold current was achieved on devices which consisted of a 2–4 μm diameter active region formed by chemical selective etching, and sandwiched between two Al0.05Ga0.95 As/ Al0.53Ga0.47 As distributed Bragg reflectors of very high reflectivity (98–99%) grown by metalorganic chemical vapor deposition.
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42.60.Da Resonators, cavities, amplifiers, arrays, and rings
42.55.Px Semiconductor lasers; laser diodes
85.60.Jb Light-emitting devices
78.55.Cr III-V semiconductors

X‐ray spectromicroscopy with a zone plate generated microprobe

Harald Ade, Janos Kirz, Steven L. Hulbert, Erik D. Johnson, Erik Anderson, and Dieter Kern

Appl. Phys. Lett. 56, 1841 (1990); http://dx.doi.org/10.1063/1.103064 (3 pages) | Cited 44 times

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The scanning photoelectron microscope at the National Synchrotron Light Source (NSLS) has recently recorded micrographs with a resolution below half a micron. To demonstrate elemental and chemical sensitivity at the submicron level, an artificial structure consisting of Al and SiO2 lines on a boron‐doped silicon substrate was examined. Al 2p and Si 2p primary photoelectrons as well as O KVV Auger electrons were used for image formation. Contrast reversal between the the Si and SiO2 areas was observed in images formed from Si 2p and oxide‐shifted Si 2p photoelectrons. The soft x‐ray undulator at the NSLS provides coherent illumination of a zone plate to produce the microprobe. The sample is mechanically scanned through the beam allowing the formation of images from photoelectrons detected by a single‐pass cylindrical mirror analyzer, or a more complete spectroscopic examination of a selected area of the sample.
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07.85.-m X- and γ-ray instruments
33.60.+q Photoelectron spectra
79.60.Jv Interfaces; heterostructures; nanostructures

Formation of InxGa1−xAs/GaAs heteroepitaxial layers using a pulsed laser driven rapid melt‐solidification process

Y. Chang, S. Y. Chou, T. W. Sigmon, A. F. Marshall, and K. H. Weiner

Appl. Phys. Lett. 56, 1844 (1990); http://dx.doi.org/10.1063/1.103065 (3 pages) | Cited 3 times

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Heteroepitaxial InxGa1−xAs/GaAs structures have been formed for the first time by pulsed laser induced mixing of molecular beam epitaxy deposited In films (∼200 Å) on GaAs (100) substrates. The process occurs by a melt‐induced, rapid‐mixing and solidification process driven by a XeCl pulsed excimer laser. The laser has a 27 ns full width at half maximum pulse width at 308 nm with its energy density of 0.28–0.61 J cm−2 homogenized into a 4×4 mm square area which is stepped across the wafer. InxGa1−xAs layers with x values, as determined by both x‐ray diffraction and Rutherford backscattering spectrometry simulation ranging from x=0.21–0.26 and thicknesses of 77–94 nm, have been formed. The formation of single‐crystal layers has been verified by 4He ion channeling and cross‐section transmission electron microscopy.
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81.15.Lm Liquid phase epitaxy; deposition from liquid phases (melts, solutions, and surface layers on liquids)
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
81.10.Fq Growth from melts; zone melting and refining

Impurity‐induced 900 °C (2×2) surface reconstruction of SrTiO3(100)

Jens E. T. Andersen and Preben J. Møller

Appl. Phys. Lett. 56, 1847 (1990); http://dx.doi.org/10.1063/1.103223 (3 pages) | Cited 14 times

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A p(2×2)surface reconstruction is observed over the 800–900 °C range for SrTiO3 (100), the temperature range which is used in the oxygen anneal of Y, Ba, Cu layers on SrTiO3 (100) substrates in the synthesis of high Tc superconducting thin films. As observed by Auger electron spectroscopy, high‐temperature annealing causes calcium to segregate to the surface. Initially, at a Ca content of 3% upon a SrO‐terminated SrTiO3 (100) surface, the Ca atom is incorporated in a superstructure, which is attributed to multiple scattering across the two topmost interfaces. When the surface Ca content is below 1% the p(2×2) surface reconstruction is induced. The p(2×2) surface reconstruction disappears when the calcium content is removed.
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68.35.B- Structure of clean surfaces (and surface reconstruction)
61.72.S- Impurities in crystals
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization

Measurement of AlGaAs/AlGaAs interface recombination velocities using time‐resolved photoluminescence

M. L. Timmons, T. S. Colpitts, R. Venkatasubramanian, B. M. Keyes, D. J. Dunlavy, and R. K. Ahrenkiel

Appl. Phys. Lett. 56, 1850 (1990); http://dx.doi.org/10.1063/1.103066 (3 pages) | Cited 11 times

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Time‐resolved photoluminescence has been used to examine AlxGa1−xAs/AlyGa1−yAs interfaces, focusing on the recombination velocity. For an Al0.08Ga0.92As/Al0.88Ga0.12As interface, important for solar cells, recombination velocities are about 104 cm/s with the growth conditions used in this study. Several types of interface passivation were attempted, but the most successful was the insertion of thin Al0.14Ga0.86As layers between the other two alloys. Using this technique, a 16‐fold increase (to ∼20 ns) of the minority‐carrier lifetime was measured in a 0.8‐μm‐thick Al0.08Ga0.92As layer in which interface recombination would normally have limited the lifetime to about 1–2 ns. Compositional grading was found to be ineffective at passivating the interfaces.
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68.35.Fx Diffusion; interface formation
68.35.Dv Composition, segregation; defects and impurities
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
78.55.Cr III-V semiconductors

Alternative approach to nanocomposite synthesis by sputtering

G. M. Chow, R. L. Holtz, A. Pattnaik, A. S. Edelstein, T. E. Schlesinger, and R. C. Cammarata

Appl. Phys. Lett. 56, 1853 (1990); http://dx.doi.org/10.1063/1.103067 (3 pages) | Cited 21 times

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A new method is presented which circumvents the usual thermodynamic limitations (alloying and compound formation) in fabricating phase‐separated materials. This opens whole new classes of materials that can be prepared as particulate composites.This method utilizes sputtering at high pressures (0.2–0.6 Torr) in a thermal gradient to produce nanoscale (<15 nm diameter) particles, which are then embedded in a matrix produced by normal sputtering. The microstructure and microhardness of 0.5‐μm‐thick composites of molybdenum particles (3–12 nm average particle size) in aluminum are presented as examples. This system cannot be prepared by the conventional phase separation technique of cosputtering.
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81.05.Ni Dispersion-, fiber-, and platelet-reinforced metal-based composites
81.05.Bx Metals, semimetals, and alloys

Topographic study on an InAs lattice‐mismatched heteroepitaxial layer grown on GaAs by means of x‐ray scattering radiography

Yoshifumi Suzuki, Yoshinori Chikaura, and Tatsushi Akazaki

Appl. Phys. Lett. 56, 1856 (1990); http://dx.doi.org/10.1063/1.103068 (3 pages) | Cited 1 time

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X‐ray scattering radiography has been successfully applied to an InAs lattice‐mismatched heteroepitaxial layer grown on GaAs (001) by molecular beam epitaxy. It was found that the lattice of the epitaxial layer varied the orientation over 18 min in arc around a [100] direction, whereas the substrate has a small lattice bend around [110] by less than 2 min in arc. The bending forms the layer into a concave with a valley along [100]. The independent lattice deformation in two layers comes from a complicated effect of the lattice mismatches and thermal expansion. Also local various structures were observed in the scattering radiographs.
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81.15.Hi Molecular, atomic, ion, and chemical beam epitaxy
68.35.B- Structure of clean surfaces (and surface reconstruction)
68.55.-a Thin film structure and morphology
61.05.cf X-ray scattering (including small-angle scattering)
61.05.cj X-ray absorption spectroscopy: EXAFS, NEXAFS, XANES, etc.

Unusual orientation relationship for a copper film on Si(111)

D. B. Knorr, P. Bai, and T.‐M. Lu

Appl. Phys. Lett. 56, 1859 (1990); http://dx.doi.org/10.1063/1.103069 (3 pages) | Cited 7 times

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The texture of a copper film deposited on bare Si(111) is studied. Deposition is done using the partially ionized beam technique where no potential is applied to the substrate. Pole figure analysis shows a very sharp texture where Cu{531} is parallel to Si(111). In the plane of the film, two variants of copper orientation are present with orientation relationships Si〈112〉//Cu〈134〉and Si〈112〉//2.5° from Cu〈350〉. The rotation between variants of 56.5° is less than the Cu(111) twin orientation. Possible reasons for the mismatch are discussed.
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68.55.-a Thin film structure and morphology
61.72.Mm Grain and twin boundaries
81.40.Ef Cold working, work hardening; annealing, post-deformation annealing, quenching, tempering recovery, and crystallization
68.35.B- Structure of clean surfaces (and surface reconstruction)

Nanoindentation study of the mechanical properties of copper‐nickel multilayered thin films

R. C. Cammarata, T. E. Schlesinger, C. Kim, S. B. Qadri, and A. S. Edelstein

Appl. Phys. Lett. 56, 1862 (1990); http://dx.doi.org/10.1063/1.103070 (3 pages) | Cited 83 times

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The mechanical properties of multilayered Cu‐Ni thin films with bilayer thicknesses of 1.6–12 nm were investigated by a nanoindentation technique. Force‐displacement curves generated during loading and unloading of a diamond tip indenter were used to determine the hardness and elastic properties of the films. No enhancement in the elastic properties (supermodulus effect) was seen, but an enhancement in the hardness was observed. It is suggested that the enhancement, which displayed a Hall–Petch‐type behavior, can be understood as owing to dislocation pinning at the interfaces analogous to the mechanism of grain boundary hardening.
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68.35.Gy Mechanical properties; surface strains
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
62.20.D- Elasticity

Two‐photon absorption in In1−x−yGaxAlyAs/InP waveguides at communications wavelengths

A. Villeneuve, M. Sundheimer, N. Finlayson, G. I. Stegeman, S. Morasca, C. Rigo, R. Calvani, and C. De Bernardi

Appl. Phys. Lett. 56, 1865 (1990); http://dx.doi.org/10.1063/1.103071 (3 pages) | Cited 10 times

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We have observed and measured two‐photon absorption in In1−x−yGaxAlyAs/InP waveguides grown by molecular beam epitaxy over the wavelength range of 1.5–1.65 μm. The values of β2, the two‐photon absorption coefficient, were 63 and 20 cm/GW for waveguides of compositions x=0.32, y=0.17 and x=0.15, y=0.31, respectively. These values are comparable with those predicted by scaling laws. We estimate the associated nonlinear refractive index coefficient n2 and discuss the implications for all‐optical switching.
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42.79.Gn Optical waveguides and couplers
78.20.Ci Optical constants (including refractive index, complex dielectric constant, absorption, reflection and transmission coefficients, emissivity)
42.65.-k Nonlinear optics

Oriented hydrocarbons transferred from a high performance lubricative amorphous C:H:Si film during sliding in a vacuum

Iwao Sugimoto and Shojiro Miyake

Appl. Phys. Lett. 56, 1868 (1990); http://dx.doi.org/10.1063/1.103072 (3 pages) | Cited 24 times

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Amorphous C:H containing silicon film shows an extremely low friction coefficient of 0.007 when the film is rubbed with a steel ball in a vacuum. This film is deposited on steel with an electron cyclotron resonance plasma of ethylene and silane. Polarized microinfrared spectroscopy reveals that high lubrication performance is attributed to hydrocarbons transferred from the rubbed film to the ball surface and oriented along the sliding direction.
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81.40.Pq Friction, lubrication, and wear
06.60.Vz Workshop procedures (welding, machining, lubrication, bearings, etc.)

Improving tunneling junction in amorphous silicon tandem solar cells

D. S. Shen, R. E. I. Schropp, H. Chatham, R. E. Hollingsworth, P. K. Bhat, and J. Xi

Appl. Phys. Lett. 56, 1871 (1990); http://dx.doi.org/10.1063/1.103073 (3 pages) | Cited 4 times

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We report new results on a tunneling junction in amorphous silicon tandem solar cells using the metal oxide, niobium oxide (NbOx ), as the recombination layer and the advanced doping gas, trimethylboron [B(CH3 )3 ], in the p+ layer. The new tunneling junction has a low series resistance and minimizes optical loss. The advantage of the NbOx layer is its high transparency, hence a relatively thick (∼10 nm) layer can be used. The ability to use a thick oxide layer is important for the implementation of the tunneling junction in the production of large‐area panels.
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73.40.Ty Semiconductor-insulator-semiconductor structures
72.80.Ng Disordered solids
73.61.Cw Elemental semiconductors
73.61.Jc Amorphous semiconductors; glasses
73.61.Le Other inorganic semiconductors

Realization of high mobilities at ultralow electron density in GaAs‐Al0.3Ga0.7As inverted heterojunctions

Dojin Kim, A. Madhukar, Ke‐Zhong Hu, and Wei Chen

Appl. Phys. Lett. 56, 1874 (1990); http://dx.doi.org/10.1063/1.103074 (3 pages) | Cited 4 times

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We report the first realization of extremely low free‐carrier concentration (≤4×1010 cm−2) and high LN2 electron mobilities (∼1.8×105 cm2/V s) in the dark in inverted Al0.3Ga0.7As /GaAs(100) modulation‐doped structures. The obtained results are all the more remarkable since the structures do not involve any superlattice or graded barrier, δ doping, or large spacer layer thicknesses. We attribute the observed properties to the high quality of the ambient in the molecular beam epitaxy system and the use of optimized growth kinetics and procedure as determined from reflection high‐energy electron diffraction intensity behavior.
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73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
73.61.Ey III-V semiconductors
72.80.Ey III-V and II-VI semiconductors

Evidence of native gallium antisite defects in semi‐insulating liquid‐encapsulated Czochralski‐grown GaAs

S. Alaya, H. Maaref, H. J. von Bardeleben, and J. C. Bourgoin

Appl. Phys. Lett. 56, 1877 (1990); http://dx.doi.org/10.1063/1.103075 (3 pages) | Cited 12 times

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We report the observation by photoluminescence of the gallium antisite double acceptor in As‐rich GaAs grown by the liquid‐encapsulated Czochralski technique. In the semi‐insulating material both arsenic antisite and gallium antisite defects are present simultaneously which must be taken into account for any electrical compensation model.
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78.55.Cr III-V semiconductors
61.72.jd Vacancies
61.72.jj Interstitials

Effect of subband mixing and subband dispersion on the exciton line shape of superlattices

J. F. Zhou, P. S. Jung, J. J. Song, and C. W. Tu

Appl. Phys. Lett. 56, 1880 (1990); http://dx.doi.org/10.1063/1.103076 (3 pages)

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We have found a very unusual exciton line shape in the vicinity of n=2 heavy hole states (HH2) of GaAs/AlxGa1−xAs superlattices. The excitonic structure consisting of a step, a sharp peak, and a broad asymmetric hump results from valence‐band mixing between HH2 and n=1 light hole states, in conjunction with subband dispersion due to well‐to‐well coupling of electrons and holes. In quantum well samples with negligible subband dispersion, a distinctly different exciton line shape is observed. The observed line shape is well fitted by a theory recently reported by Chu and Chang [Phys. Rev. B 39, 10861 (1989)].
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73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.Fd III-V semiconductors
78.66.Hf II-VI semiconductors
78.55.Cr III-V semiconductors

Pyrolysis of trimethylgallium on GaAs(100) surfaces

Ulrich Memmert and Ming L. Yu

Appl. Phys. Lett. 56, 1883 (1990); http://dx.doi.org/10.1063/1.103224 (3 pages) | Cited 35 times

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We have used a combination of pulsed molecular beam and time‐resolved mass spectrometry to study the kinetics of the pyrolysis of trimethylgallium on GaAs(100) surfaces. We found that CH3 is the major reaction product. Two CH3 desorption channels were observed, with activation energies 37.9±1.6 and 45.0±1.4 kcal/mole. An arsine ambient significantly accelerates the CH3 desorption, but no CH4 was observed. A model for the reaction of trimethylgallium on the GaAs(100) surface is proposed.
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81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
82.20.Pm Rate constants, reaction cross sections, and activation energies
68.43.-h Chemisorption/physisorption: adsorbates on surfaces
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)

Normally‐off high‐contrast asymmetric Fabry–Perot reflection modulator using Wannier–Stark localization in a superlattice

K‐K. Law, R. H. Yan, J. L. Merz, and L. A. Coldren

Appl. Phys. Lett. 56, 1886 (1990); http://dx.doi.org/10.1063/1.103077 (3 pages) | Cited 24 times

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A normally‐off surface normal Fabry–Perot reflection modulator with a contrast ratio of more than 60:1 with an operating voltage swing of 8 V has been demonstrated. The asymmetric Fabry–Perot structure consists of 100 periods of a 30 Å GaAs/30 Å Al0.3Ga0.7As superlattice sandwiched between a highly reflecting quarter‐wavelength stack on the substrate side, and a less reflecting front mirror (air‐semiconductor interface) on the top. The net Fabry–Perot reflection is turned on by reducing the cavity loss at resonance through the blue‐shifted electroabsorption effect of Wannier–Stark localization in the superlattice.
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42.79.Hp Optical processors, correlators, and modulators
07.60.-j Optical instruments and equipment
42.79.-e Optical elements, devices, and systems
78.20.Jq Electro-optical effects

Capacitance‐voltage characteristics of alternating‐current thin‐film electroluminescent devices

R. C. McArthur, J. D. Davidson, J. F. Wager, I. Khormaei, and C. N. King

Appl. Phys. Lett. 56, 1889 (1990); http://dx.doi.org/10.1063/1.103078 (3 pages) | Cited 14 times

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The capacitance‐voltage (C‐V) technique is proposed as a method for characterization of the electrical properties of alternating‐current thin‐film electroluminescent (ACTFEL) display devices. Analysis of the C‐V and aging characteristics of ZnS:Mn ACTFEL devices indicates that the C‐V technique is complementary to the charge‐voltage technique in the extraction of device physics information.
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78.60.Fi Electroluminescence
85.60.Jb Light-emitting devices
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)
85.60.Pg Display systems
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