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

8 Feb 1999

Volume 74, Issue 6, pp. 777-892

Page 2 of 2 Pages Previous Page | Jump to Page
back to top
RSS Feeds

Investigation of excess carrier diffusion in nitride semiconductors with near-field optical microscopy

Andrey Vertikov, Ilker Ozden, and Arto V. Nurmikko

Appl. Phys. Lett. 74, 850 (1999); http://dx.doi.org/10.1063/1.123387 (3 pages) | Cited 20 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe a high-spatial-resolution optical technique to study transport properties in semiconductors, applicable especially to heterostructures characterized by short-carrier diffusion lengths on the 100 nm scale. The method involves spatial near-field optical imaging of photoluminescence profiles created by an interference grating within a total internal reflection configuration. We illustrate the method by applying it as a diagnostic tool to a contemporary problem, namely, to acquire insight into electron–hole pair recombination in InGaN, a blue light-emitting medium exhibiting pronounced nonrandom alloy characteristics. © 1999 American Institute of Physics.
Show PACS
72.80.Ey III-V and II-VI semiconductors
73.40.Kp III-V semiconductor-to-semiconductor contacts, p-n junctions, and heterojunctions
72.20.Jv Charge carriers: generation, recombination, lifetime, and trapping
78.55.Cr III-V semiconductors
back to top
RSS Feeds

Intrinsic picosecond response times of Y–Ba–Cu–O superconducting photodetectors

M. Lindgren, M. Currie, C. Williams, T. Y. Hsiang, P. M. Fauchet, Roman Sobolewski, S. H. Moffat, R. A. Hughes, J. S. Preston, and F. A. Hegmann

Appl. Phys. Lett. 74, 853 (1999); http://dx.doi.org/10.1063/1.123388 (3 pages) | Cited 46 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report our femtosecond time-resolved measurements on the photoresponse of an epitaxial YBa2Cu3O7−x (YBCO) thin-film photodetector, patterned into a microbridge geometry. By varying the current–voltage biasing conditions between the superconducting and resistive (hot spot) states, we observed transients that correspond to the nonequilibrium kinetic-inductance and the nonequilibrium electron-heating response mechanisms, respectively. The two-temperature model and the Rothwarf–Taylor theory have been used to simulate the measured wave forms and to extract the temporal parameters. The electron thermalization time and the electron–phonon energy relaxation time were determined by the electron temperature rise and decay times, which were found to be 0.56 and 1.1 ps, respectively, in the resistive state. We have also measured the ratio between the phonon and electron specific heats to be 38, which corresponds to a phonon–electron scattering time of 42 ps. No phonon-trapping effect (typical for low-temperature superconductors) was observed in YBCO, in the superconducting state, so the quasiparticle lifetime was given by the quasiparticle recombination time, estimated from the Rothwarf–Taylor equations to be below 1 ps. © 1999 American Institute of Physics.
Show PACS
85.25.Pb Superconducting infrared, submillimeter and millimeter wave detectors
85.60.Gz Photodetectors (including infrared and CCD detectors)
74.78.-w Superconducting films and low-dimensional structures
74.72.-h Cuprate superconductors
74.25.Gz Optical properties
74.25.Kc Phonons
85.25.Cp Josephson devices

Crystallographic and magnetic properties of intermetallic compound Nd3Co13B2

Yi Chen, Q. L. Liu, J. K. Liang, X. L. Chen, B. G. Shen, and F. Huang

Appl. Phys. Lett. 74, 856 (1999); http://dx.doi.org/10.1063/1.123389 (3 pages) | Cited 10 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The crystal structure and magnetic properties of the intermediate compound Nd3Co13B2 have been investigated by x-ray diffraction and magnetic measurement. Nd3Co13B2 is a member of homologous series Rm+1Co5m+3B2 with m = 2. It adopts the hexagonal La3Ni13B2-type structure with lattice parameters a = 5.0722(4) Å and c = 10.7840(5) Å. The Nd3Co13B2 compound is ferromagnetic with a Curie temperature of 420 K. Its saturation magnetic moment and anisotropy field are 20.8 μB/f.u. and 163 kOe at 1.5 K, respectively. © 1999 American Institute of Physics.  
Show PACS
61.66.Dk Alloys
75.50.Cc Other ferromagnetic metals and alloys
75.30.Kz Magnetic phase boundaries (including classical and quantum magnetic transitions, metamagnetism, etc.)
75.40.-s Critical-point effects, specific heats, short-range order
75.30.Gw Magnetic anisotropy
75.30.Cr Saturation moments and magnetic susceptibilities
back to top
RSS Feeds

A robust and powerful green light photoemission source: The ferroelectric ceramics

A. Doria, G. P. Gallerano, L. Giannessi, E. Giovenale, I. Boscolo, R. Parafioriti, A. Porcari, A. Scurati, M. Castellano, L. Catani, M. Ferrario, P. Patteri, F. Tazzioli, and J. Handerek

Appl. Phys. Lett. 74, 859 (1999); http://dx.doi.org/10.1063/1.123390 (3 pages) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Show Abstract
The photoemission characteristics of ceramic disks of lead zirconate titanate lanthanum doped (PLZT), have been investigated. We observe 1 nC of extracted charge under an accelerating field of 20 kV/cm in poor vacuum conditions. The emission is clearly limited by space charge effects. The extrapolated quantum efficiency results in ≈ 10−6. The yield of a PLZT ceramic in the ferroelectric state and its slope versus light intensity have turned out higher than those of antiferroelectric ceramic. Samples in different experimental configurations have shown different nonlinear yields. © 1999 American Institute of Physics.
Show PACS
77.84.Ek Niobates and tantalates
77.84.Cg PZT ceramics and other titanates
77.80.-e Ferroelectricity and antiferroelectricity
79.60.Bm Clean metal, semiconductor, and insulator surfaces
85.60.Ha Photomultipliers; phototubes and photocathodes
back to top
RSS Feeds

Corrugated quantum well infrared photodetectors for polarization detection

C. J. Chen, K. K. Choi, L. Rokhinson, W. H. Chang, and D. C. Tsui

Appl. Phys. Lett. 74, 862 (1999); http://dx.doi.org/10.1063/1.123391 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this letter, we propose the use of the newly developed corrugated quantum well infrared photodetectors (C-QWIPs) for polarization detection. The corrugated structure, which serves as an optical coupler as well as the polarization-sensitive component, is in this case directly created into the active region of the QWIP, therefore dispensed with the need of an external polarizer. Moreover, four C-QWIPs with differently oriented corrugated patterns can be integrated as one unit, thus allowing a precise, real-time measurement of the polarization state. The polarimetry of this detector unit was characterized using a blackbody source and a metal grating polarizer. © 1999 American Institute of Physics.  
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
42.79.Gn Optical waveguides and couplers

Bright-blue electroluminescence from a silyl-substituted ter-(phenylene–vinylene) derivative

Zhiqiang Gao, C. S. Lee, I. Bello, S. T. Lee, Ruey-Ming Chen, Tien-Yau Luh, J. Shi, and C. W. Tang

Appl. Phys. Lett. 74, 865 (1999); http://dx.doi.org/10.1063/1.123392 (3 pages) | Cited 79 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A bright-blue electroluminescent device has been fabricated by using an emissive dopant and an electron-transporting host. The dopant was a highly photoluminescent silyl-substituted ter-(phenylene–vinylene) derivative [1,4-bis[4-(2-trimethylsilylvinly) styryl]-2,5-dibutoxybenzene (BTSB)]. BTSB was doped into a trimer of N-arylbenzimidazoles (TPBI) which functioned as the host and electron transporter. N,N′-bis-(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4-4′-diamine (NPB) was used as the hole transporter. The device, with a structure of indium tin oxide\NPB\TPBI:10%BTSB\TPBI\Mg:Ag, shows a bright blue emission of 11000 cd/m2 at a current density of 360 mA/cm2. The current efficiency of this device is about 3.2 cd/A at 20 mA/cm2. © 1999 American Institute of Physics.
Show PACS
78.60.Fi Electroluminescence

A fully lithographed voltage-biased superconducting spiderweb bolometer

J. M. Gildemeister, Adrian T. Lee, and P. L. Richards

Appl. Phys. Lett. 74, 868 (1999); http://dx.doi.org/10.1063/1.123393 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe the fabrication and characterization of superconducting transition-edge bolometers for astrophysical applications at far-infrared and mm wavelengths. The sensor is voltage biased and the current is measured with a superconducting quantum interference ammeter. Strong negative electrothermal feedback keeps the sensor temperature nearly constant, reduces the response time significantly, and improves linearity. It also makes the responsivity relatively insensitive to changes in optical background loading and refrigerator temperature. The bolometers are made using standard microlithographic techniques suitable for fabrication of large scale arrays. Detailed measurements of optical response are presented for a range of bias conditions and are compared with theory. Measured noise spectra are shown and a model for the noise is presented. © 1999 American Institute of Physics.
Show PACS
95.55.Rg Photoconductors and bolometers
85.25.Pb Superconducting infrared, submillimeter and millimeter wave detectors
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.25.Am Superconducting device characterization, design, and modeling
95.55.Jz Radio telescopes and instrumentation; heterodyne receivers

Dual function hybrid polymer-nanoparticle devices

K. S. Narayan, A. G. Manoj, J. Nanda, and D. D. Sarma

Appl. Phys. Lett. 74, 871 (1999); http://dx.doi.org/10.1063/1.123394 (3 pages) | Cited 24 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Dual properties of photoconduction and electroluminescence (EL) in hybrid devices consisting of a nanocluster semiconductor layer and a polymer are reported. It is observed that the photocurrent spectral response and efficiency in these multilayer devices are similar to that of the semiconductor component, while the EL spectral responses are closer to that of the polymer layer. The results are confirmed using the nanoparticle semiconductor, cadmium sulphide CdS, of different particle sizes and polymers representing a wide spectral range. A general feature of efficient photocurrent spectral response corresponding to nanoparticle and an appreciable EL response corresponding more to the active polymer are observed in all devices and results in wide, separated spectral windows. Current–voltage responses also indicate possibilities of added tunability in these devices. © 1999 American Institute of Physics.
Show PACS
78.66.Hf II-VI semiconductors
73.61.Ga II-VI semiconductors
78.60.Fi Electroluminescence
78.66.Qn Polymers; organic compounds
73.22.-f Electronic structure of nanoscale materials and related systems
73.50.Pz Photoconduction and photovoltaic effects
back to top
RSS Feeds

Noninvasive absorption and scattering spectroscopy of bulk diffusive media: An application to the optical characterization of human breast

R. Cubeddu, A. Pifferi, P. Taroni, A. Torricelli, and G. Valentini

Appl. Phys. Lett. 74, 874 (1999); http://dx.doi.org/10.1063/1.123395 (3 pages) | Cited 34 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
A time-resolved reflectance and transmittance spectrophotometer was developed and used to evaluate noninvasively and simultaneously the absorption and transport scattering spectra of bulk turbid media. The experimental setup, based on mode-locked dye and titanium:sapphire lasers and on an electronic chain for time-correlated single photon counting, was fully automated to make in vivo measurements on biological tissues feasible. The optical characterization of breast, of interest for the development of optical mammography, was performed in vivo on a wide spectral range (610–1010 nm). In particular, the absorption spectral features of the main tissue components (hemoglobin, water, and lipids) were recognized with different relative weight, depending on the age and the measurement position. Best fit with the absorption spectra of the main constituents was performed to evaluate their relative concentration in tissues. © 1999 American Institute of Physics.
Show PACS
87.64.K- Spectroscopy
87.63.L- Visual imaging
87.64.Cc Scattering of visible, uv, and infrared radiation
42.62.Be Biological and medical applications

Abiotic synthesis of amino acids by x-ray irradiation of simple inorganic gases

Jun-ichi Takahashi, Teruo Hosokawa, Hitomi Masuda, Takeo Kaneko, Kensei Kobayashi, Takeshi Saito, and Yuichi Utsumi

Appl. Phys. Lett. 74, 877 (1999); http://dx.doi.org/10.1063/1.123396 (3 pages) | Cited 13 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
1–2 keV x-ray irradiation was carried out using a synchrotron radiation source on simulated primitive earth environment: a gas mixture of carbon monoxide, nitrogen, and water at atmospheric pressure. High-speed liquid chromatography of the hydrolyzed product solution detected amino acids. The amount of amino acids increased with the total energy absorbed by the gas molecules, and the antipodal optical isomers were generated in almost equal quantities. These imply that the precursors for amino acids were produced through x-ray-induced photolysis of inorganic molecules followed by recombination and polymerization into bio-organic compounds. These results suggest that prebiotic formation of amino acids is possible in primitive earth atmosphere by x ray as well as cosmic ray. © 1999 American Institute of Physics.
Show PACS
82.50.Kx Processes caused by X-rays or γ-rays
82.80.Bg Chromatography
87.15.R- Reactions and kinetics
back to top
RSS Feeds

A photoelectron spectroscopy study on the indium tin oxide treatment by acids and bases

F. Nüesch, L. J. Rothberg, E. W. Forsythe, Quoc Toan Le, and Yongli Gao

Appl. Phys. Lett. 74, 880 (1999); http://dx.doi.org/10.1063/1.123397 (3 pages) | Cited 88 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report on the chemical adsorption of acids and bases on indium tin oxide (ITO). Ultraviolet photoelectron spectroscopy was used to measure the work function of the treated ITO and atomic surface concentrations were determined by x-ray photoelectron spectroscopy. The acid treatments yield work-function shifts as high as 0.7 eV compared to the nontreated ITO. Huge shifts in the work function are also obtained for the treatments with bases and are opposite to those obtained with the acids. These dramatic shifts are indicative of a double ionic surface layer. The importance of an appropriate plasma treatment prior to the chemical adsorption of acids or bases is discussed in terms of surface acido-basicity. © 1999 American Institute of Physics.
Show PACS
79.60.Dp Adsorbed layers and thin films
82.80.Pv Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)
68.03.Fg Evaporation and condensation of liquids
68.43.Mn Adsorption kinetics
68.43.-h Chemisorption/physisorption: adsorbates on surfaces
73.30.+y Surface double layers, Schottky barriers, and work functions
81.65.-b Surface treatments

Development of a low-temperature GaN chemical vapor deposition process based on a single molecular source H2GaN3

Jeff McMurran, J. Kouvetakis, and David J. Smith

Appl. Phys. Lett. 74, 883 (1999); http://dx.doi.org/10.1063/1.123398 (3 pages) | Cited 16 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the development of a simple and highly efficient chemical approach to growing GaN thin films between 150 and 700 °C using a single molecular source, H2GaN3. Uncommonly low-temperature growth of nanocrystalline GaN films with a wurtzite structure is readily achieved at 150–200 °C from the thermodynamically driven decomposition of the precursor via complete elimination of the stable and relatively benign H2 and N2 by-products. Highly oriented columnar growth of crystalline material is obtained on Si at 350–700 °C and heteroepitaxial growth on sapphire at 650 °C. Crucial advantages of this precursor include: significant vapor pressure which permits rapid mass transport at 22 °C; and the facile decomposition pathway of stoichiometric elimination of H2 and N2 over a wide temperature and pressure range which allows film growth at very low temperatures and pressures (10−4–10−8 Torr) with growth rates up to 80 nm per minute. © 1999 American Institute of Physics.
Show PACS
81.05.Ea III-V semiconductors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.Kk Vapor phase epitaxy; growth from vapor phase
68.55.-a Thin film structure and morphology
82.30.Lp Decomposition reactions (pyrolysis, dissociation, and fragmentation)

Resistless patterning of Si for processing

Kumar Shiralagi and Raymond Tsui

Appl. Phys. Lett. 74, 886 (1999); http://dx.doi.org/10.1063/1.123399 (3 pages) | Cited 5 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Results are presented on our efforts in the patterning of Si wafers without using photoresist. The process is similar to the recently reported surface modification of GaAs with ultraviolet (UV) light to produce a stable mask surface. However, in the absence of an easily modifiable surface oxide on Si, a hydrogen-passivated and oxide-free Si surface is exposed to UV light in the presence of oxygen to form an oxide in the irradiated regions. Selective Si growth and etching were demonstrated on wafers so patterned, and preliminary results showing the promise of this technique are reported in this letter. © 1999 American Institute of Physics.
Show PACS
85.40.Hp Lithography, masks and pattern transfer
81.65.Cf Surface cleaning, etching, patterning
81.65.Rv Passivation
61.80.Ba Ultraviolet, visible, and infrared radiation effects (including laser radiation)
61.82.Fk Semiconductors

Effect of oxygen plasma treatment on field emission characteristics of boron–nitride films

Takashi Sugino and Shigeru Tagawa

Appl. Phys. Lett. 74, 889 (1999); http://dx.doi.org/10.1063/1.123400 (3 pages) | Cited 12 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Field emission properties of boron–nitride (BN) films synthesized by plasma-assisted chemical vapor deposition are investigated. There appears a hysteresis of the field emission characteristic for as-grown BN films. It is found that the hysteresis is suppressed for the BN films treated with O2 plasma. Moreover, no significant degradation of the field emission characteristics occurs although a slight generation of B2O3 is detected at the BN surface by O2 plasma treatment. © 1999 American Institute of Physics.
Show PACS
79.70.+q Field emission, ionization, evaporation, and desorption
81.05.Ea III-V semiconductors
52.77.Bn Etching and cleaning
52.77.Dq Plasma-based ion implantation and deposition
81.65.-b Surface treatments
back to top
RSS Feeds
FREE

Comment on “Noise gain and detectivity of n-type GaAs/AlAs/AlGaAs quantum well infrared photodetectors” [Appl. Phys. Lett. 73, 1251 (1998)]

B. F. Levine

Appl. Phys. Lett. 74, 892 (1999); http://dx.doi.org/10.1063/1.123957 (1 page) | Cited 1 time

Full Text: Read Online (HTML) | Download PDF

Abstract Unavailable
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
81.05.Ea III-V semiconductors
73.61.Ey III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
FREE

Response to “Comment on ‘Noise gain and detectivity of n-type GaAs/AlGaAs quantum well infrared photodetectors’ ” [Appl. Phys. Lett. 74, 892 (1999)]

C. Schönbein, H. Schneider, R. Rehm, and M. Walther

Appl. Phys. Lett. 74, 892 (1999); http://dx.doi.org/10.1063/1.123958 (1 page)

Full Text: Read Online (HTML) | Download PDF

Abstract Unavailable
Show PACS
07.57.Kp Bolometers; infrared, submillimeter wave, microwave, and radiowave receivers and detectors
85.60.Gz Photodetectors (including infrared and CCD detectors)
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.61.Ey III-V semiconductors
73.50.Td Noise processes and phenomena
Page 2 of 2 Pages Previous Page | Jump to Page
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close