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

4 Sep 1995

Volume 67, Issue 10, pp. 1343-1491

Page 1 of 2 Pages Next Page | Jump to Page

Self‐pulsating lasers with quantum well saturable absorber

R. C. P. Hoskens, T. G. van de Roer, C. J. van der Poel, and H. P. M. Ambrosius

Appl. Phys. Lett. 67, 1343 (1995); http://dx.doi.org/10.1063/1.115545 (3 pages) | Cited 12 times

Full Text: | Download PDF

Show Abstract
Self‐pulsations are induced in broad area diode lasers by including an extra layer functioning as a saturable absorber. The absorption of this layer and its coupling to the photon field can be tuned via the layer thickness and its distance to the active layer. In the case of an Al0.13GaAs bulk active layer a GaAs absorber of 4 nm thickness at a distance of 0.2 μm induces stable oscillations with frequencies of 300–700 MHz in a current range just above the threshold. © 1995 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.55.Rz Doped-insulator lasers and other solid state lasers

2.7‐μm InGaAsSb/AlGaAsSb laser diodes with continuous‐wave operation up to −39 °C

D. Z. Garbuzov, R. U. Martinelli, R. J. Menna, P. K. York, H. Lee, S. Y. Narayan, and J. C. Connolly

Appl. Phys. Lett. 67, 1346 (1995); http://dx.doi.org/10.1063/1.115546 (3 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
We have demonstrated continuous wave operation of 2.7‐μm InGaAsSb/AlGaAsSb multiquantum‐well diode lasers up to a temperature of 234 K (−39 °C). These devices were grown by molecular‐beam‐epitaxy. They have a tendency to operate in a dominant single mode over well‐defined temperature and current intervals. A comparison of spontaneous emission spectra shows that above threshold, the quasi‐Fermi level is pinned and that most of the carriers are injected into nonlasing states. This effect leads to a rapid decrease of differential efficiency with increasing temperature. © 1995 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.-v Laser optical systems: design and operation

GaN linear electro‐optic effect

X.‐C. Long, R. A. Myers, S. R. J. Brueck, R. Ramer, K. Zheng, and S. D. Hersee

Appl. Phys. Lett. 67, 1349 (1995); http://dx.doi.org/10.1063/1.115547 (3 pages) | Cited 17 times

Full Text: | Download PDF

Show Abstract
Measurements of the linear (Pockels) electro‐optical coefficient of wurtzite GaN are reported. The values for the electro‐optic coefficients r33 and r31 are 1.91±0.35 and 0.57±0.11 pm/V at 633 nm, respectively, in agreement with extrapolations from measured second‐harmonic generation coefficients (χ33(2)=−20±6 pm/V and χ31(2)=10±3 pm/V) suggesting that the dominant contributions are electronic in origin. Measurements were performed using a Mach–Zehnder interferometer with LiNbO3 as a reference material. Piezoelectric effects were also observed. © 1995 American Institute of Physics.
Show PACS
78.20.Jq Electro-optical effects
78.66.Fd III-V semiconductors

Spectroscopic and photorefractive properties of molybdenum‐doped barium titanate

Robert N. Schwartz, Barry A. Wechsler, and Linda West

Appl. Phys. Lett. 67, 1352 (1995); http://dx.doi.org/10.1063/1.115548 (3 pages) | Cited 20 times

Full Text: | Download PDF

Show Abstract
Molybdenum‐doped barium titanate crystals have been grown and characterized. Electron paramagnetic resonance spectroscopy has confirmed the presence of Mo5+ centers in reduced crystals that correlate with a strong optical absorption band at ∼600 nm. Self‐pumped phase‐conjugation and electro‐optic beam‐coupling measurements indicate that the reduced crystals are photorefractive in the visible, as well as the near‐infrared wavelength region. © 1995 American Institute of Physics.
Show PACS
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials

Electroluminescence from a conjugated polymer microcavity structure

T. A. Fisher, D. G. Lidzey, M. A. Pate, M. S. Weaver, D. M. Whittaker, M. S. Skolnick, and D. D. C. Bradley

Appl. Phys. Lett. 67, 1355 (1995); http://dx.doi.org/10.1063/1.115549 (3 pages) | Cited 28 times

Full Text: | Download PDF

Show Abstract
We report the observation of electroluminescence and photoluminescence from microcavity structures containing poly(2,5‐dialkoxy‐p‐phenylene vinylene) (PDAOPV) conjugated polymer emitting regions. Strong spectral narrowing from 112 nm full width half‐maximum to 34 nm in electroluminescence and from 128 to 16 nm in photoluminescence and clear angular dependence of the peak emission wavelength are observed. These are characteristic signatures of the modification of spontaneous emission properties in microcavity structures. © 1995 American Institute of Physics.
Show PACS
42.50.-p Quantum optics
78.55.Kz Solid organic materials
78.66.Qn Polymers; organic compounds

Generation of terahertz radiation from a poled polymer

Ajay Nahata, David H. Auston, Chengjiu Wu, and James T. Yardley

Appl. Phys. Lett. 67, 1358 (1995); http://dx.doi.org/10.1063/1.115550 (3 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
We report the generation of terahertz radiation via optical rectification from a poled polymer using femtosecond optical pulses. We have measured the refractive index and power absorption in the terahertz frequency range. The corresponding difference frequency mixing coherence length in the poled polymer (1 mm at 1 THz) is ∼20 times greater than that of LiNbO3 (50 μm at 1 THz). The observed far‐infrared electric field radiated from a 16 μm thick polymer sample is only 4 times smaller than that from a 1 mm thick y‐cut LiNbO3 crystal. We discuss conversion efficiencies for thicker polymer samples. © 1995 American Institute of Physics.
Show PACS
42.65.Ky Frequency conversion; harmonic generation, including higher-order harmonic generation
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.70.Jk Polymers and organics

Thermal lens determination of end‐pumped solid‐state lasers with transverse beat frequencies

B. Ozygus and J. Erhard

Appl. Phys. Lett. 67, 1361 (1995); http://dx.doi.org/10.1063/1.115551 (2 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
By measuring the beat frequency of adjacent transverse modes it is possible to determine the thermal lensing of end‐pumped laser crystals. Because frequencies are used the method is very precise. Even for very weak thermal lensing the technique can be applied. © 1995 American Institute of Physics.
Show PACS
42.55.Rz Doped-insulator lasers and other solid state lasers
42.60.Da Resonators, cavities, amplifiers, arrays, and rings

Time‐bandwidth product of gain‐switched In0.2Ga0.8As/GaAs microcavity lasers

P. Michler, W. W. Rühle, G. Reiner, K. J. Ebeling, and A. Moritz

Appl. Phys. Lett. 67, 1363 (1995); http://dx.doi.org/10.1063/1.115534 (3 pages) | Cited 1 time

Full Text: | Download PDF

Show Abstract
We present the temporal and spectral evolution of stimulated emission from In0.2Ga0.8As/GaAs microcavity laser samples at 20 K after femtosecond optical excitation. Both, linewidth and chirp become smaller when the cavity resonance is at shorter wavelengths within the gain spectrum of the quantum well: The linewidth is reduced from Δλ=0.41 nm at 923 nm, where the threshold is lowest, to Δλ=0.26 nm at 884 nm. Comparison with a phenomenological model yields linewidth enhancement factors α of 2 and 5 for emission wavelengths of 884 and 925 nm, respectively. A time‐bandwidth product of 0.68 is obtained at the shorter wavelength. © 1995 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Jf Beam characteristics: profile, intensity, and power; spatial pattern formation
78.47.-p Spectroscopy of solid state dynamics

High power continuous wave atomic Xe laser with radio frequency excitation

P. P. Vitruk, R. J. Morley, H. J. Baker, and D. R. Hall

Appl. Phys. Lett. 67, 1366 (1995); http://dx.doi.org/10.1063/1.115535 (3 pages) | Cited 7 times

Full Text: | Download PDF


See Also: Erratum

Show Abstract
Radio frequency discharges in Ar/He/Xe gas mixtures have been studied in the range 5–150 MHz, and the importance of the ion sheaths in Xe laser excitation has been recognized. The discharge data have been used to improve the cw Xe laser performance, and efficiencies up to 0.8% observed. Area scaling in the slab geometry has been studied for α discharge excitation at 49 MHz, and multimode cw laser power up to 5.5 W has been observed. High quality beams have been produced at 4.9 W using a hybrid waveguide/unstable resonator. © 1995 American Institute of Physics.
Show PACS
42.55.Lt Gas lasers including excimer and metal-vapor lasers
42.60.-v Laser optical systems: design and operation

Two‐stage nanostructural formation process in Fe–Nb–B soft magnetic alloys

K. Suzuki, J. M. Cadogan, J. B. Dunlop, and V. Sahajwalla

Appl. Phys. Lett. 67, 1369 (1995); http://dx.doi.org/10.1063/1.115536 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
The nanostructural formation kinetics in a soft magnetic Fe80Nb6B14 alloy have been investigated by means of differential scanning calorimetry, thermogravimetric analysis and transmission electron microscopy. Unlike nanocrystalline Fe–Zr–B soft magnetic alloys, where the nanocrystallite formation is governed mostly by a nucleation and growth mechanism, the nanostructural formation mechanism in the Fe–Nb–B alloy shows a change in the fraction transformed range 0.1–0.2. The first‐ and second‐stage nanostructural formation processes have been described by the nucleation and growth and grain‐growth models, respectively. This two‐stage nature in the nanostructural formation kinetics can be attributed to a high population density of the primary bcc nuclei. © 1995 American Institute of Physics.
Show PACS
61.43.-j Disordered solids
75.50.Kj Amorphous and quasicrystalline magnetic materials
81.05.Rm Porous materials; granular materials

Increase in the infrared response of silicide Schottky barrier diodes by grain boundary scattering

E. Roca, K. Kyllesbech Larsen, S. Kolodinski, and R. Mertens

Appl. Phys. Lett. 67, 1372 (1995); http://dx.doi.org/10.1063/1.115537 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
The infrared response of polycrystalline and epitaxial CoSi2/Si Schottky diodes with similar silicide thickness has been measured. For the polycrystalline diodes the quantum efficiency is found to be two times higher than for the epitaxial diodes, although both types of diodes present very similar barrier height. The observed improvement is attributed to grain boundary scattering of the excited carriers. © 1995 American Institute of Physics.
Show PACS
73.30.+y Surface double layers, Schottky barriers, and work functions
85.60.Gz Photodetectors (including infrared and CCD detectors)

Diode‐laser‐based atomic absorption monitor using frequency‐modulation spectroscopy for physical vapor deposition process control

Weizhi Wang, R. H. Hammond, M. M. Fejer, C. H. Ahn, M. R. Beasley, M. D. Levenson, and M. L. Bortz

Appl. Phys. Lett. 67, 1375 (1995); http://dx.doi.org/10.1063/1.115538 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
We have developed an atomic monitoring system for physical vapor deposition process control based on a frequency‐modulation (FM) spectroscopy scheme using a 670 nm external cavity diode laser. FM detection made it possible to measure absorption as low as 10−6. For electron‐beam evaporated yttrium, deposition rate control with a relative accuracy better than 1% at a rate of 3.5 Å/s has been realized, corresponding to a deposition rate resolution of 0.03 Å/s. Variations in Doppler shifts due to the velocity distribution of the atomic vapor within the deposition chamber have been measured, demonstrating the possibility of velocity mapping of evaporated atoms in the deposition process. © 1995 American Institute of Physics.
Show PACS
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy

Nanofabrication of a two‐dimensional array using laser‐focused atomic deposition

R. Gupta, J. J. McClelland, Z. J. Jabbour, and R. J. Celotta

Appl. Phys. Lett. 67, 1378 (1995); http://dx.doi.org/10.1063/1.115539 (3 pages) | Cited 54 times

Full Text: | Download PDF

Show Abstract
Fabrication of a two‐dimensional array of nanometer‐scale chromium features on a silicon substrate by laser‐focused atomic deposition is described. Features 13±1 nm high and having a full‐width at half maximum of 80±10 nm are fabricated in a square array with lattice constant 212.78 nm, determined by the laser wavelength. The array covers an area of approximately 100 μm×200 μm. Issues associated with laser‐focusing of atoms in a two‐dimensional standing wave are discussed, and potential applications and improvements of the process are mentioned.
Show PACS
81.15.-z Methods of deposition of films and coatings; film growth and epitaxy
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

Electro‐optic modulation and self‐poling in strain‐induced waveguides in barium strontium titanate niobate

J. M. Marx, O. Eknoyan, H. F. Taylor, Z. Tang, and R. R. Neurgaonkar

Appl. Phys. Lett. 67, 1381 (1995); http://dx.doi.org/10.1063/1.115540 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
Characterization of bulk single crystals and optical waveguides in Ba1−xSrxTiyNb2−yO6 (BSTN) indicate it to be a promising new ferroelectric material for electrooptic devices. The electro‐optic coefficient r33 is measured to be 218±12 pm/V, a factor of 7 greater than LiNbO3. Data on refractive indices, dielectric constant, and Curie temperature Tc in bulk samples are also presented. Strain‐induced waveguides in Z‐cut samples exhibited low losses (1.8 dB/cm for TM polarization and 2.5 dB/cm for TE polarization) at a wavelength of 1.3 μm. Electro‐optic modulation was demonstrated in these waveguides to frequencies ≳100 MHz. A ‘‘self‐poling’’ effect was found, whereby strong electro‐optic modulation is observed in the strain waveguides without repoling the crystal after processing at temperatures far above Tc. © 1995 American Institute of Physics.
Show PACS
42.65.An Optical susceptibility, hyperpolarizability
42.70.Nq Other nonlinear optical materials; photorefractive and semiconductor materials
78.20.Jq Electro-optical effects

Tritertiarybutylaluminum as an organometallic source for epitaxial growth of AlGaSb

C. A. Wang, M. C. Finn, S. Salim, K. F. Jensen, and A. C. Jones

Appl. Phys. Lett. 67, 1384 (1995); http://dx.doi.org/10.1063/1.115541 (3 pages) | Cited 14 times

Full Text: | Download PDF

Show Abstract
A new organometallic source, tritertiarybutylaluminum (TTBAl), has been used in growth of AlxGa1−xSb epilayers by low pressure organometallic vapor phase epitaxy. Ternary alloys were grown over the whole composition range 0<x≤1 on GaSb and GaAs substrates from TTBAl, triethylgallium, and triethylantimony (TESb) or trimethylantimony (TMSb). All layers exhibited mirror surface morphologies. Photoluminescence was observed for layers with x<0.2, the composition that corresponds to the indirect transition. The background of C and O in AlSb grown with TESb was ∼2×1018 and ∼6×1019 cm−3, respectively, and ∼1.5×1019 and ∼1.5×1019 cm−3, respectively, for AlSb grown with TMSb. All layers exhibited p‐type conductivity with hole concentration increasing with x, and saturating ∼5×1018 cm−3 for x=1, which is about 10 times lower compared to layers grown with conventional Al sources. © 1995 American Institute of Physics.
Show PACS
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Structure and properties of epitaxial Ba0.5Sr0.5TiO3/SrRuO3/ZrO2 heterostructure on Si grown by off‐axis sputtering

S. Y. Hou, J. Kwo, R. K. Watts, J.‐Y. Cheng, and D. K. Fork

Appl. Phys. Lett. 67, 1387 (1995); http://dx.doi.org/10.1063/1.115542 (3 pages) | Cited 33 times

Full Text: | Download PDF

Show Abstract
We report the growth and characterization of epitaxial Ba0.5Sr0.5TiO3/SrRuO3/ZrO2 on Si for potential charge storage applications. Both Ba0.5Sr0.5TiO3 (BST) and SrRuO3 (SRO) are grown (110)‐oriented on yttrium‐stabilized ZrO2 (YSZ) (100)‐buffered Si. These films show a high degree of crystallinity with minimal interdiffusion at the interfaces as evidenced from x‐ray diffraction, Rutherford backscattering, and transmission electron microscopy. Studies on the in‐plane crystallographic relations between the layers revealed an interesting rectangle‐on‐cube epitaxy between BST/SRO and YSZ. The dielectric constant and loss tangent of the BST dielectric layer are 360 and 0.01 at 10 kHz, respectively. The leakage current density is lower than 4×10−7 A/cm2 at 1 V. A strong frequency dependence on both dielectric constant and loss tangent is observed in 1–10 MHz frequency range. This is attributed to the effect of a series resistance in the measurement loop, which is likely related to the bottom SrRuO3 electrode. © 1995 American Institute of Physics.  
Show PACS
68.55.-a Thin film structure and morphology
73.40.Qv Metal-insulator-semiconductor structures (including semiconductor-to-insulator)

High crystalline quality ZnSe films grown by pulsed laser deposition

M. Y. Chern, H. M. Lin, C. C. Fang, J. C. Fan, and Y. F. Chen

Appl. Phys. Lett. 67, 1390 (1995); http://dx.doi.org/10.1063/1.115543 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
We have grown epitaxial ZnSe films on (001)GaAs substrates at 300 °C by pulsed laser deposition (PLD). Before the growth, thin buffer layers of GaAs are also grown by PLD at 300 °C. While the pattern of reflection high energy electron diffraction (RHEED) of the buffer layers is spotty, the pattern of the ZnSe films subsequently grown is streaky, and shows distinct Kikuchi lines and bands. The x‐ray rocking curve width of the films is as narrow as 150 arcsec. Photoluminescence (PL) at 10 K of the films shows free and bound excitons, donor‐acceptor pairs (DAP), and is free of any deep level emissions, indicating good crystalline quality of the films. Scanning electron microscopy (SEM) shows that the particulate number density of the films is only about 1 particulate per 400 μm2. © 1995 American Institute of Physics.
Show PACS
81.15.Fg Pulsed laser ablation deposition

Piezoelectric field effects in InGaAs (111)B quantum wells

X. Chen, C. H. Molloy, D. A. Woolf, C. Cooper, D. J. Somerford, P. Blood, K. A. Shore, and J. Sarma

Appl. Phys. Lett. 67, 1393 (1995); http://dx.doi.org/10.1063/1.115544 (3 pages) | Cited 7 times

Full Text: | Download PDF

Show Abstract
Strained In0.21Ga0.79As/GaAs quantum well structures have been grown by molecular beam epitaxy on (111)B GaAs substrates. Well widths between 20 and 160 Å, separated by 500 Å barriers were grown sequentially on the same substrate and subsequently characterized by low‐temperature (10 K) photoluminescence. The variation of the e‐hh transition energy with well width is markedly different for samples grown simultaneously on (100) and (111)B substrates due to the strain induced piezoelectric field. Using the envelope function approximation, the dependence of n=1 e‐hh transitions of (111)B samples on well width can be interpreted by the presence of a built‐in electric field of magnitude of 1.45×107 V/m. In contrast to the (100) sample, exciton lifetimes in the (111)B sample depend strongly on well width because of spatial separation of electrons and holes in the triangular wells. In the 160 Å well, the exciton lifetime increases to 755 ns corresponding to a reduction of about three orders of magnitude in the electron‐hole wave function overlap integral. © 1995 American Institute of Physics.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.55.Cr III-V semiconductors

Role of dangling bond centers on radiative recombination processes in porous silicon

Yasunori Mochizuki and Masashi Mizuta

Appl. Phys. Lett. 67, 1396 (1995); http://dx.doi.org/10.1063/1.114505 (3 pages) | Cited 9 times

Full Text: | Download PDF

Show Abstract
The role of Si dangling bonds (Pb center) on the broad luminescence band around 1.1 eV of porous Si is discussed, based on transient wave form measurement of optically detected magnetic resonance. The observed wave form is compatible with the nongeminate shunt path scheme and the characteristic time constant of this nonradiative process is deduced to be 15 μs at 1.6 K, whereas the competing radiative channel has a shorter decay time of 3 μs. Therefore, Pb centers are unlikely to be involved as a radiative state in this infrared luminescence. Results are also discussed in conjunction with the visible luminescence process. © 1995 American Institute of Physics.
Show PACS
71.55.Ht Other nonmetals
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
78.55.Hx Other solid inorganic materials

Impact of supplemental implantation of oxygen on defect centers in the separation by implantation of oxygen structure

K. Vanheusden and A. Stesmans

Appl. Phys. Lett. 67, 1399 (1995); http://dx.doi.org/10.1063/1.114506 (3 pages) | Cited 2 times

Full Text: | Download PDF

Show Abstract
The influence of supplemental O+ implantation on standard separation‐by‐implantation of oxygen (SIMOX) structures in terms of inherent defects has been analyzed by electron spin resonance. The monitored defects include the Eγ′ and Eδ′ variants of the oxygen‐deficiency centers in the buried oxide layer (BOX), and the likely O‐related, shallow donor (UL1) centers in buried interfacial Si layers. E′ generation sensitivity depth profiles were mapped using etch back in combination with E′ generation by exposure to a dc Ar glow discharge. A major finding is that supplemental O implantation significantly reduces the E′ generation sensitivity (precursor sites) quite uniformly all over the BOX layer. The reduction, though, is about two times greater for Eδ′ as compared to Eγ′. The UL1 centers, by contrast, are seen to increase by up to a factor 6. Apparently these defects, inherent to the SIMOX formation process, are insufficiently removed by the postsupplemental O+ implantation anneal performed at 1100 °C. © 1995 American Institute of Physics.
Show PACS
61.72.uf Ge and Si
61.80.Jh Ion radiation effects
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Enhanced Zn diffusion in GaAs pnpn structures: Growth versus annealing

C. Y. Chen, R. M. Cohen, D. S. Simons, and P. H. Chi

Appl. Phys. Lett. 67, 1402 (1995); http://dx.doi.org/10.1063/1.114507 (3 pages) | Cited 5 times

Full Text: | Download PDF

Show Abstract
Zn diffusivity, DZn in heavily doped pnpn GaAs structures has been measured after growth and annealing. During growth at 650 °C, DZn∼10−12 cm2/s in the buried p‐type layer is found to be ≳104×DZn in the top p‐type layer. During annealing at 800 °C, DZn≊5×10−14 cm2/s in the buried layer remains orders of magnitude larger than DZn in the top layer. The measurements provide clear experimental evidence that (1) a large flux of Ga interstitials, IGa, is injected from the surface during the growth of n‐type layers, (2) the IGa are trapped in the buried p‐type layer by the electric field of the pn junctions, and are thus positively charged, (3) the resulting large concentration of IGa in the buried layer accounts for the enhanced DZn via a kick‐out mechanism, and (4) the mobile Zn interstitial is positively charged. © 1995 American Institute of Physics.
Show PACS
61.72.uj III-V and II-VI semiconductors
66.30.J- Diffusion of impurities
68.55.Ln Defects and impurities: doping, implantation, distribution, concentration, etc.

Band diagram of the polycrystalline CdS/Cu(In,Ga)Se2 heterojunction

L. Kronik, L. Burstein, M. Leibovitch, Yoram Shapira, D. Gal, E. Moons, J. Beier, G. Hodes, David Cahen, D. Hariskos, R. Klenk, and H.‐W. Schock

Appl. Phys. Lett. 67, 1405 (1995); http://dx.doi.org/10.1063/1.114508 (3 pages) | Cited 25 times

Full Text: | Download PDF

Show Abstract
Contact potential difference measurements in the dark and under illumination are used to derive the conduction band offset (ΔEc) in a solar cell quality junction formed by chemical bath deposition of CdS on a polycrystalline thin film of Cu(In,Ga)Se2. Our experimental measurements and the estimates made for dipole contributions show that the junction is of type II, i.e., without a spike in the conduction band ( ΔEc=80 meV±100 meV). This is consistent with the high performance of the actual solar cell. However, it differs from most previous results on junctions based on single crystals and/or vacuum deposited CdS, which indicated the existence of a conduction band spike. © 1995 American Institute of Physics.
Show PACS
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
73.50.Pz Photoconduction and photovoltaic effects
84.60.Jt Photoelectric conversion

Photorefractive p‐i‐n diode quantum well spatial light modulators

I. Lahiri, K. M. Kwolek, D. D. Nolte, and M. R. Melloch

Appl. Phys. Lett. 67, 1408 (1995); http://dx.doi.org/10.1063/1.114509 (3 pages) | Cited 34 times

Full Text: | Download PDF

Show Abstract
We demonstrate the performance of all‐semiconductor photorefractive p‐i‐n diodes operating in the longitudinal quantum‐confined Stark geometry. Low‐temperature‐grown shallow quantum wells provide high‐mobility vertical transport, and potential steps incorporated into the semiconductor buffer layers increase the transit time across the buffer and therefore increase the quantum efficiency for trapping of charge before it is swept out to the doped p‐type and n‐type contacts. The buffer design and the doped contacts both make all‐semiconductor photorefractive devices possible, with peak transient output diffraction efficiencies approaching 3%, but without the need for dielectric insulating layers. We also redefine device speed by making a distinction between transient rise times and frequency response, showing that in these p‐i‐n devices the update rate is an order of magnitude slower than the inverse rise time. © 1995 American Institute of Physics.
Show PACS
42.65.Jx Beam trapping, self-focusing and defocusing; self-phase modulation
42.79.Hp Optical processors, correlators, and modulators
78.66.Fd III-V semiconductors

The properties of a metal/oxide semiconductor junction prepared using a high‐purity ozone surface treatment

Takashi Shimizu and Hideyo Okushi

Appl. Phys. Lett. 67, 1411 (1995); http://dx.doi.org/10.1063/1.114510 (3 pages) | Cited 13 times

Full Text: | Download PDF

Show Abstract
Electrical properties of the junction between a metal and an oxide semiconductor whose surface has been treated with high‐purity ozone were investigated. In situ treatment of ozone on the surfaces of Nb‐doped SrTiO3 (NSTO) and Nb‐doped TiO2 (NTO) and in situ deposition of Au have been performed to make metal/semiconductor junctions. The I–V characteristics of the junctions show high rectification properties (the rectification ratios are over a ninth order of magnitude when the junctions are biased at 1.3 V) and the capacitance–voltage (C–V) characteristics show linear C−2–V relationships in the reverse condition. These results have indicated that the surface treatment of the oxide semiconductors using high‐purity ozone and in situ deposition of metal electrodes drastically improve the Schottky properties of oxide semiconductor diodes. © 1995 American Institute of Physics.
Show PACS
73.30.+y Surface double layers, Schottky barriers, and work functions
73.40.Ns Metal-nonmetal contacts

Low‐temperature, uniform, and high‐density plasma produced by a new ultra‐high‐frequency discharge with a spokewise antenna

Seiji Samukawa, Yukito Nakagawa, Tsutomu Tsukada, Hiroyuki Ueyama, and Kibatsu Shinohara

Appl. Phys. Lett. 67, 1414 (1995); http://dx.doi.org/10.1063/1.114511 (3 pages) | Cited 16 times

Full Text: | Download PDF

Show Abstract
A low‐temperature, uniform, high‐density plasma is produced by an ultra‐high‐frequency (UHF) discharge with a new spokewise antenna. The plasma is uniform within ±5% over a diameter of 20 cm. The plasma density, 5×1010 cm−3 for low‐electron temperatures of 1.5–2.0 eV, is almost proportional to the UHF power even at a low‐UHF power of 100 W. No magnetic field is needed to maintain a high‐density plasma. Consequently, the plasma source is fairly simple and lightweight. The plasma source should ease serious problems in etching processes that use conventional high‐density plasmas. © 1995 American Institute of Physics.
Show PACS
52.50.-b Plasma production and heating
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
52.80.Pi High-frequency and RF discharges
Page 1 of 2 Pages Next Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close