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

7 Aug 2000

Volume 77, Issue 6, pp. 767-915

Return to All Sections
back to top
RSS Feeds

Luminescence properties of GaN and Al0.14Ga0.86N/GaN superlattice doped with europium

H. J. Lozykowski, W. M. Jadwisienczak, J. Han, and I. G. Brown

Appl. Phys. Lett. 77, 767 (2000); http://dx.doi.org/10.1063/1.1306645 (3 pages) | Cited 38 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the observation of visible photoluminescence and cathodoluminescence of Eu3+ ions implanted in GaN and Al0.14Ga0.86N/GaN superlattice. The sharp characteristic emission lines corresponding to Eu3+ intra-4f6-shell transitions are resolved and observed over the temperature range of 7–330 K. The luminescence shows dominant transitions 5D0→7F1,2,3 and weaker 5D0→7F4,5,6 and 5D1→7F1. The luminescence emission is very weakly temperature dependent. The intensity of Eu3+ emission from Al0.14Ga0.86N/GaN superlattice annealed in N2 is ∼58% stronger than from Eu3+ in the GaN layer. The Al0.14Ga0.86N/GaN superlattice and GaN epilayers may be suitable as a material for visible optoelectronic devices. © 2000 American Institute of Physics.
Show PACS
78.66.Fd III-V semiconductors
78.55.Cr III-V semiconductors
78.60.Hk Cathodoluminescence, ionoluminescence
71.55.Eq III-V semiconductors
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems

Submicrometer resolution Yablonovite templates fabricated by x-ray lithography

C. Cuisin, A. Chelnokov, J.-M. Lourtioz, D. Decanini, and Y. Chen

Appl. Phys. Lett. 77, 770 (2000); http://dx.doi.org/10.1063/1.1306646 (3 pages) | Cited 14 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We report the fabrication and optical characterization of diamond-like photonic structures with 1.3 μm lattice constants. In analogy with the first Yablonovite obtained by a mechanical drilling of a dielectric material, the structures are fabricated in poly(methylmethacrylate) resist using three consecutive exposures to an x-ray beam through a triangular lattice of holes. Up to six crystal periods are obtained in a 6.2-μm-thick resist. The measured reflection and transmission spectra show well contrasted photonic gaps in agreement with numerical simulations. This demonstrates the good optical quality of the structures that can be used as porous templates for transferring the diamond-like pattern to high-refractive-index dielectrics or metals. © 2000 American Institute of Physics.
Show PACS
42.70.Qs Photonic bandgap materials
42.82.Cr Fabrication techniques; lithography, pattern transfer
78.66.Qn Polymers; organic compounds
78.30.Jw Organic compounds, polymers
42.70.Jk Polymers and organics

Room-temperature gain and differential gain characteristics of self-assembled InGaAs/GaAs quantum dots for 1.1–1.3 μm semiconductor lasers

Nobuaki Hatori, Mitsuru Sugawara, Kohki Mukai, Yoshiaki Nakata, and Hiroshi Ishikawa

Appl. Phys. Lett. 77, 773 (2000); http://dx.doi.org/10.1063/1.1306662 (3 pages) | Cited 25 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
This letter presents an explanation of the optical gain and differential gain of two types of self-assembled quantum dots in the laser active region, which shows 1.16 and 1.31 μm spontaneous emission from the ground state at room temperature. The gain spectrum was measured using the Hakki–Paoli method up to the lasing threshold. The maximum optical gain of the ground state was found to be 150–400 cm−1 and the differential gain to be 3×10−15–1×10−16 cm2, which agrees quite well with the calculation, taking into account both homogeneous broadening and inhomogeneous broadening. Our results will be a guide to the design of laser structures. © 2000 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Da Resonators, cavities, amplifiers, arrays, and rings
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
78.66.Fd III-V semiconductors

Determination of the band offset and the characteristic interdiffusion length in quantum-well lasers using a capacitance–voltage technique

J. Arias, I. Esquivias, E. C. Larkins, S. Bürkner, S. Weisser, and J. Rosenzweig

Appl. Phys. Lett. 77, 776 (2000); http://dx.doi.org/10.1063/1.1306660 (3 pages) | Cited 4 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
In this work, a capacitance–voltage (C–V) technique, based on a combination of measured and simulated C–V characteristics, was applied to characterize In0.35Ga0.65As/GaAs multiquantum-well laser structures at room temperature. A theoretical model, including the self-consistent solution of Poisson and Schrödinger equations, was developed to simulate the C–V characteristics and the carrier concentration profiles. Measured C–V carrier concentration profiles were used to obtain the average impurity concentration in active regions. The comparison between experimental and simulated results was used to determine the conduction band offset, yielding ΔEc/ΔEg ≈ 0.8. In the case of samples with postgrowth quantum-well intermixing, this technique was applied to extract the characteristic interdiffusion length. © 2000 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
85.35.Be Quantum well devices (quantum dots, quantum wires, etc.)
73.21.-b Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems
66.30.Ny Chemical interdiffusion; diffusion barriers
68.65.-k Low-dimensional, mesoscopic, nanoscale and other related systems: structure and nonelectronic properties
73.61.Ey III-V semiconductors

Oxide and hydrogen capped ultrasmall blue luminescent Si nanoparticles

Gennadiy Belomoin, Joel Therrien, and Munir Nayfeh

Appl. Phys. Lett. 77, 779 (2000); http://dx.doi.org/10.1063/1.1306659 (3 pages) | Cited 83 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We dispersed electrochemical etched silicon into a colloid of ultrasmall ultrabright Si nanoparticles. Direct imaging using transmission electron microscopy shows particles of ∼1 nm in diameter, and infrared and electron photospectroscopy show that they are passivated with hydrogen. Under 350 nm excitation, the luminescence is dominated by an extremely strong blue band at 390 nm. We replace hydrogen by a high-quality ultrathin surface oxide cap by self-limiting oxidation in H2O2. Upon capping, the excitation efficiency drops, but only by a factor of 2, to an efficiency still two-fold larger than that of fluorescein. Although of slightly lower brightness, capped Si particles have superior biocompatability, an important property for biosensing applications. © 2000 American Institute of Physics.
Show PACS
78.66.Vs Fine-particle systems
61.46.-w Structure of nanoscale materials
78.55.Ap Elemental semiconductors
81.65.Rv Passivation
81.07.-b Nanoscale materials and structures: fabrication and characterization
78.30.Am Elemental semiconductors and insulators
78.66.Db Elemental semiconductors and insulators
81.65.Mq Oxidation
87.64.K- Spectroscopy

Ultrabroadband AIGaAs/CaF2 semiconductor saturable absorber mirrors

S. Schön, M. Haiml, and U. Keller

Appl. Phys. Lett. 77, 782 (2000); http://dx.doi.org/10.1063/1.1306917 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Ultrabroadband semiconductor saturable absorber mirrors (SESAMs) are required to support self-starting sub-10-fs-pulse generation with Ti:sapphire lasers. Conventional AlxGa1−xAs/AlAs SESAMs are limited by the reflection bandwidth of about 60 nm of the bottom Bragg mirror. In this letter, we demonstrate a GaAs saturable absorber which is epitaxially grown on CaF2 using molecular-beam epitaxy. Even though the difference of the thermal expansion coefficient is very large, we were able to demonstrate good modulation depth with small nonsaturable losses. This is interesting for ultrabroadband SESAMs because the large refractive-index difference between CaF2 and AlxGa1−xAs results in very broadband AlxGa1−xAs/CaF2 Bragg mirrors extending over about a 400-nm-wide reflection bandwidth for a center wavelength of 850 nm. © 2000 American Institute of Physics.
Show PACS
42.50.Md Optical transient phenomena: quantum beats, photon echo, free-induction decay, dephasings and revivals, optical nutation, and self-induced transparency
42.65.Re Ultrafast processes; optical pulse generation and pulse compression
42.60.Fc Modulation, tuning, and mode locking
42.79.Bh Lenses, prisms and mirrors

Designing finite-height two-dimensional photonic crystal waveguides

T. Søndergaard, A. Bjarklev, M. Kristensen, J. Erland, and J. Broeng

Appl. Phys. Lett. 77, 785 (2000); http://dx.doi.org/10.1063/1.1306915 (3 pages) | Cited 9 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
Guidelines for designing planar waveguides based on introducing line-defects in two-dimensional photonic-crystal slabs are obtained by comparing calculations on two-dimensional structures with dispersion relations for the media above and below the slab. © 2000 American Institute of Physics.
Show PACS
42.82.Et Waveguides, couplers, and arrays
42.79.Gn Optical waveguides and couplers
42.70.Qs Photonic bandgap materials

Tunable piezoelectric semiconductor laser controlled by the carrier injection level

V. Ortiz, N. T. Pelekanos, Guido Mula, and Le Si Dang

Appl. Phys. Lett. 77, 788 (2000); http://dx.doi.org/10.1063/1.1306908 (3 pages) | Cited 2 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We propose a tunable laser diode based on a piezoelectric heterostructure. The tuning mechanism consists of modulating the gain spectrum during lasing by the quantum-confined Stark effect. The modulating electric field is produced by carrier separation in the active region, and its amplitude depends on the injected carrier density. In a proof-of-principle photopumped experiment, we were able to generate a space-charge field of 20 kV/cm which shifted the lasing wavelength by more than 3 nm in the 800 nm spectral region. © 2000 American Institute of Physics.
Show PACS
42.55.Px Semiconductor lasers; laser diodes
42.60.Fc Modulation, tuning, and mode locking
77.84.Bw Elements, oxides, nitrides, borides, carbides, chalcogenides, etc.
73.61.Ga II-VI semiconductors
78.66.Hf II-VI semiconductors
77.22.Jp Dielectric breakdown and space-charge effects
78.20.Jq Electro-optical effects

Photoresponsivity of ultraviolet detectors based on InxAlyGa1−x−yN quaternary alloys

T. N. Oder, J. Li, J. Y. Lin, and H. X. Jiang

Appl. Phys. Lett. 77, 791 (2000); http://dx.doi.org/10.1063/1.1306540 (3 pages) | Cited 17 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
We describe the growth, fabrication, and characterization of an ultraviolet (UV) photoconductive detector based on InxAlyGa1−x−yN quaternary alloy that is lattice matched to GaN. The detector consisted of 0.1 μm InxAlyGa1−x−yN alloy grown on 0.5–1.0 μm GaN epilayer by metalorganic chemical vapor deposition. With varying indium concentration, the cut-off wavelength of the InxAlyGa1−x−yN detectors could be varied to the deep UV range. The most important and intriguing result is that the responsivity of the InxAlyGa1−x−yN quaternary alloy exceeded that of AlGaN alloy of a comparable cutoff wavelength by a factor of five. This makes the nitride quaternary alloy very important material for solar blind UV detectors applications particularly in the deep UV range where Al rich AlGaN alloys have problems with low quantum efficiency and cracks due in part to lattice mismatch with GaN. The advantages of InxAlyGa1−x−yN quaternary over AlGaN ternary alloys for UV detector applications are also discussed. © 2000 American Institute of Physics.
Show PACS
85.60.Gz Photodetectors (including infrared and CCD detectors)
81.05.Ea III-V semiconductors
73.61.Ey III-V semiconductors
78.66.Fd III-V semiconductors
42.79.Pw Imaging detectors and sensors
81.15.Gh Chemical vapor deposition (including plasma-enhanced CVD, MOCVD, ALD, etc.)
81.15.Kk Vapor phase epitaxy; growth from vapor phase

Finite-source dye-diffusion thermal transfer for doping and color integration of organic light-emitting devices

Chung-chih Wu, Cheng-chung Yang, Hsin-hua Chang, Chieh-Wei Chen, and Cheng-Chung Lee

Appl. Phys. Lett. 77, 794 (2000); http://dx.doi.org/10.1063/1.1306293 (3 pages) | Cited 8 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An effective process of performing controllable doping of polymer films in organic light-emitting devices is reported. In this approach, a film to be doped is brought into direct contact with a dye-dispersed polymer donor film to permit direct dye-diffusion thermal transfer. Theoretical and experimental studies indicate that this doping process can be modeled by Fick’s diffusion theory and that a desired dopant distribution may be obtained in a single transfer step by adjusting the diffusion conditions. Doped-polymer light-emitting devices made by this process exhibited the same device characteristics as those by the conventional blending process. Along with patterned color donor plates, we also demonstrated multicolor devices of arbitrary patterns over large areas with a single thermal transfer step. © 2000 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
81.05.Lg Polymers and plastics; rubber; synthetic and natural fibers; organometallic and organic materials
66.30.J- Diffusion of impurities
85.60.Pg Display systems
78.66.Qn Polymers; organic compounds

Organic–inorganic hybrid electroluminescence device fabricated by conjugated polymer and ZnS:Mn

Xiaohui Yang and Xurong Xu

Appl. Phys. Lett. 77, 797 (2000); http://dx.doi.org/10.1063/1.1306390 (3 pages) | Cited 17 times

Full Text: Read Online (HTML) | Download PDF

Show Abstract
An organic–inorganic hybrid device was fabricated. The architecture of the hybrid device consisted of two layers sandwiched between two injecting electrodes, one of which was a conjugated polymer layer and the other was an inorganic material layer. Emission from both the organic and inorganic layers was observed, but the mechanisms of luminescence for the layers were different. Our primary results suggest the possibility of integrating different types of luminescence into one device structure. © 2000 American Institute of Physics.
Show PACS
85.60.Jb Light-emitting devices
78.66.Hf II-VI semiconductors
42.70.Jk Polymers and organics
78.66.Qn Polymers; organic compounds
Return to All Sections
Close

Google Calendar

ADVERTISEMENT

Go to AIP Home   © AIP Publishing LLC
close