scholarly journals Defect Characterization in ZnGeP2 by Time -Resolved Photoluminescence

1996 ◽  
Vol 450 ◽  
Author(s):  
N. Dietz ◽  
W. Busse ◽  
H. E. Gumlich ◽  
W. Ruderman ◽  
I. Tsveybak ◽  
...  
Keyword(s):  
Energy Range ◽  
Infrared Emission ◽  
Luminescence Spectra ◽  
Broad Emission Band ◽  
Wide Energy Range ◽  
Time Resolved ◽  
Broad Emission ◽  
Donor Acceptor ◽  
Donor States ◽  
Time Resolved Photoluminescence

AbstractSteady state and time-resolved photoluminescence (PL) investigations on ZnGeP2 crystals grown from the vapor phase by high pressure physical vapor transport (HPVT) and from the melt by gradient freezing (GF) are reported. The luminescence spectra reveal a broad infrared emission with peak position at 1.2 eV that exhibits features of classical donor-acceptor recombination. The hyperbolic decay characteristic over a wide energy range, investigated from 1.2 eV up to 1.5eV, suggest that this broad emission band is related to one energetic recombination center. Higher energetic luminescence structures at 1.6eV and 1.7eV were revealed after annealing of ZnGeP2 crystals in vacuum for a longer period of time. The emission decay behavior in this energy range is characterized by two hyperbolic time constants, viewed as the supercomposition of the decay from the broad emission center peaked at 1.2eV and additional donor-acceptor recombination emissions at 1.6eV and 1.7eV, respectively. ZnGeP2 crystals grown under Ge-deficient conditions by HPVT show an additional emission structure at 1.8 eV with sharp emission fine structures at 1.778 eV related to the presence of additional donor states.

Native Defect Characterization in ZnGeP2

1999 ◽  
Vol 607 ◽  
Author(s):  
A. Hoffmann ◽  
H. Born ◽  
A. Näser ◽  
W. Gehlhoff ◽  
J. Maffetone ◽  
...  
Keyword(s):  
Energy Range ◽  
Infrared Emission ◽  
Peak Position ◽  
Metastable Equilibrium ◽  
Chalcopyrite Structure ◽  
Luminescence Spectra ◽  
Broad Emission Band ◽  
Cation Sublattice ◽  
Broad Emission ◽  
Donor Acceptor

AbstractElectron paramagnetic resonance (EPR) as well as time-resolved and time-integrated photoluminescence (PL) are used to characterize the defect centers in ZnGeP2 bulk crystals. The samples, as-grown, electron-irradiated and annealed, reveal a strong intensity dependence of the VZn-correlated EPR-transitions. Photo-EPR experiments show that this intensity behavior is mainly caused by a recharging of the VZn centers owing to the preparation induced shift of the Fermi-level. The luminescence spectra show a broad infrared emission with peak position at 1.23 eV that exhibits features of classical donor-acceptor recombination. The hyperbolic decay characteristics, investigated in energy range from 1.2 eV up to 1.5eV, suggest that this broad emission band is related to one energetic recombination center. This recombination is interpreted to be between donor-acceptor states related to residual disorder on the cation sublattice that is retained in metastable equilibrium during the formation of the chalcopyrite structure. The emission decay behavior in the energy range from 1.2 eV up to 1.6 eV is characterized by two hyperbolic time constants, and explained as the super-composition of the decays from the broad emission center peaked at 1.2 eV and an additional donor-acceptor recombination centers at 1.4 eV.

Time-Resolved Energy-Dispersive XAFS Station for Wide-Energy Range at SPring-8

2007 ◽  
Author(s):  
K. Kato ◽  
T. Uruga ◽  
H. Tanida ◽  
S. Yokota ◽  
K. Okumura ◽  
...  
Keyword(s):  
Energy Range ◽  
Energy Dispersive ◽  
Wide Energy Range ◽  
Time Resolved ◽  
Wide Energy

Time-resolved photoluminescence in CdIn2S4

1987 ◽  
Vol 65 (3) ◽  
pp. 204-207 ◽  
Author(s):  
S. Charbonneau ◽  
E. Fortin ◽  
J. Beauvais
Keyword(s):  
Single Crystals ◽  
Free Electron ◽  
Continuous Wave ◽  
Time Window ◽  
Photoluminescence Spectra ◽  
Time Resolved ◽  
Spectral Bands ◽  
Window Technique ◽  
Donor Acceptor ◽  
Time Resolved Photoluminescence

Photoluminescence spectra of CdIn2S4 single crystals at 1.8 K under both continuous-wave (CW) and pulsed excitation were obtained. In the latter case, a variable time-window technique was used to observe the time evolution of the spectra between 0 and 100 μs. In contrast to previous studies, four spectral bands were observed under both CW and pulsed, intrinsic or extrinsic excitation. In particular, two bands previously unobserved under extrinsic excitation were detected at 1.35 and 1.68 eV, and have been attributed to donor–acceptor pairs and free-electron to acceptor transitions respectively.

scholarly journals Localized Surface Plasmon on 6H SiC with Ag Nanoparticles

2017 ◽  
Vol 897 ◽  
pp. 634-637
Author(s):  
Yi Wei ◽  
Ahmed Fadil ◽  
Hai Yan Ou
Keyword(s):  
Ag Nanoparticles ◽  
Internal Quantum Efficiency ◽  
Minority Carrier Lifetime ◽  
Fdtd Simulation ◽  
Localized Surface Plasmon ◽  
Ag Nanoparticle ◽  
Ag Nps ◽  
Time Resolved ◽  
Donor Acceptor ◽  
Time Resolved Photoluminescence

Silver (Ag) nanoparticles (NPs) were deposited on the surface of bulk Nitrogen-Boron co-doped 6H silicon carbide (SiC), and the Ag NPs were observed to induce localized surface plasmons (LSP) resonances on the SiC substrate, which was expected to improve the internal quantum efficiency (IQE) of the emissions of the donor-acceptor pairs of the SiC substrate. Room-temperature measurements of photoluminescence (PL), transmittance and time-resolved photoluminescence (TRPL) were applied to characterize the LSP resonances. Through the finite-difference time-domain (FDTD) simulation of the LSP resonance of an Ag nanoparticle on the SiC substrate, it is predicted that when the diameter of the cross section on the xy plane of the Ag nanoparticle is greater than 225 nm, the LSP starts to enhance the PL intensity. With implementation of a 3rd order exponential decay fitting model to the TRPL results, it is found that the average minority carrier lifetime of the SiC substrate decreased.

scholarly journals Time Resolved Photoluminescence of Cubic Mg Doped GaN

1999 ◽  
Vol 572 ◽  
Author(s):  
R. Seitz ◽  
C. Gaspar ◽  
T. Monteiro ◽  
E. Pereira ◽  
B. Schoettker ◽  
...  
Keyword(s):  
Blue Emission ◽  
Spectral Shift ◽  
Excitation Density ◽  
Acceptor Pair ◽  
Time Resolved ◽  
Deep Donor ◽  
Cubic Gan ◽  
Donor Acceptor ◽  
Time Resolved Photoluminescence ◽  
Mg Doped

ABSTRACTMg doped cubic GaN layers were studied by steady state and time resolved photoluminescence. The blue emission due to Mg doping can be decomposed in three bands. The decay curves and the spectral shift with time delays indicates donor-acceptor pair behaviour. This can be confirmed by excitation density dependent measurements. Furthermore temperature dependent analysis shows that the three emissions have one impurity in common. We propose that this is an acceptor level related to the Mg incorporation and the three deep donor levels are due to compensation effects.

scholarly journals On the origin of the 2.8 eV blue emission in p-type GaN:Mg : A time-resolved photoluminescence investigation

2001 ◽  
Vol 6 ◽  
Author(s):  
F. Shahedipour ◽  
B.W. Wessels
Keyword(s):  
Luminescence Intensity ◽  
Random Distribution ◽  
Blue Emission ◽  
Acceptor Pair ◽  
Time Resolved ◽  
Donor Acceptor ◽  
Shallow Acceptors ◽  
Donor Acceptor Pair ◽  
P Type ◽  
Time Resolved Photoluminescence

The decay dynamics of the 2.8 eV emission band in p-type GaN was investigated using time-resolved photoluminescence spectroscopy. The luminescence intensity decays non-exponentially. The decay dynamics were consistent with donor-acceptor pair recombination for a random distribution of pair distances. Calculations using the Thomas-Hopfield model indicated that recombination involves deep donors and shallow acceptors.

Optical Fabrication of Semiconductor Single-Crystalline Microspheres in Superfluid Helium

2014 ◽  
Vol 1635 ◽  
pp. 103-108 ◽  
Author(s):  
Shinya Okamoto ◽  
Satoshi Ichikawa ◽  
Yosuke Minowa ◽  
Masaaki Ashida
Keyword(s):  
Superfluid Helium ◽  
Luminescence Spectra ◽  
Ultraviolet Region ◽  
Optical Fabrication ◽  
Strong Light ◽  
Time Resolved ◽  
Light Matter Interaction ◽  
Time Resolved Photoluminescence ◽  
Spherical Microparticles ◽  
Typical Mode

ABSTRACTWe successfully fabricated semiconductor microspheres of ZnO, ZnSe, etc., by laser ablation in superfluid helium and investigated their morphology and optical properties. Time-resolved photoluminescence spectroscopy in ultraviolet region of single ZnO microspheres shows luminescence spectra with mode structures and remarkable reduction of the luminescence decay time compared to that of polycrystals or non-spherical microparticles. This indicates strong light-matter interaction due to efficient light-confinement in the ZnO microspheres. In addition, the fabricated ZnSe microspheres also show the photoluminescence spectra with typical mode structures indicating their high sphericity.

A Luminescent Probe Study of Water/Acetonitrile Mixtures

1979 ◽  
Vol 32 (2) ◽  
pp. 271 ◽  
Author(s):  
AJ Easteal
Keyword(s):  
Salicylic Acid ◽  
Luminescence Band ◽  
Composition Dependence ◽  
Water Structure ◽  
Luminescence Spectra ◽  
Broad Emission Band ◽  
Luminescent Probe ◽  
Broad Emission ◽  
Alcohol Mixtures ◽  
Water Alcohol

Luminescence spectra for 1.0 × 10-2 mol dm-3 solutions of salicylic acid in water, acetonitrile and water/acetonitrile mixtures have been determined. In the wavelength range 300-600 nm, all spectra showed a single broad emission band. The variations of the wavelength of maximum luminescence intensity (λmax) and luminescence band half-width (Δ�) with solvent composition are similar to the composition dependence of these parameters observed previously for solutions of salicylic acid in water/alcohol mixtures. The invariance of Δ� with acetonitrile content up to approximately 15 mole% supports earlier conclusions that up to c. 15 mole% acetonitrile is accommodated within cavities in the water structure. The rapid increase in near 15 mole% acetonitrile provides further evidence for a progressive destruction of the water structure as the acetonitrile content is increased beyond c. 15 mole%.

Sign in / Sign up

Export Citation Format

Share Document