Titanium Related Luminescence in SiC

2008 ◽  
Vol 600-603 ◽  
pp. 461-464 ◽  
Author(s):  
Anne Henry ◽  
Peder Bergman ◽  
Erik Janzén
Keyword(s):  
Low Temperature ◽  
Excitation Energy ◽  
High Energy ◽  
Luminescence Spectra ◽  
Time Resolved ◽  
Phonon Line ◽  
Long Lifetime ◽  
Time Resolved Photoluminescence ◽  
Phonon Structure

We report on the luminescence spectra related to Ti impurity in both 4H- and 6H-SiC polytypes. The spectrum depends strongly on the polarization. They are two families of lines in 4H and three in 6H. The main no-phonon line of each family is shown as a triplet and its phonon structure contains both sharp and broad replicas. The higher energy family has also extra lines at high energy appearing when the temperature increases. The spectra can be detected with excitation energy below the excitonic bandgap and even with excitation energy below the spectrum itself. Time-resolved photoluminescence reveals 0.1 ms long lifetime at low temperature.

The promises and perfidy of cryomicroscopy and analysis

1994 ◽  
Vol 52 ◽  
pp. 382-383
Author(s):  
Patrick Echlin
Keyword(s):  
Low Temperature ◽  
High Energy ◽  
Short Paper ◽  
List Type ◽  
Time Resolved ◽  
Energy Beam ◽  
Cellular Analysis ◽  
Dissolved Ions ◽  
Embedding Medium ◽  
Low Temperature Microscopy

The unusual title of this short paper and its accompanying tutorial is deliberate, because the intent is to investigate the effectiveness of low temperature microscopy and analysis as one of the more significant elements of the less interventionist procedures we can use to prepare, examine and analyse hydrated and organic materials in high energy beam instruments. The promises offered by all these procedures are well rehearsed and the litany of petitions and responses may be enunciated in the following mantra.Vitrified water can form the perfect embedding medium for bio-organic samples.Frozen samples provide an important, but not exclusive, milieu for the in situ sub-cellular analysis of the dissolved ions and electrolytes whose activities are central to living processes.The rapid conversion of liquids to solids provides a means of arresting dynamic processes and permits resolution of the time resolved interactions between water and suspended and dissolved materials.The low temperature environment necessary for cryomicroscopy and analysis, diminish, but alas do not prevent, the deleterious side effects of ionizing radiation.Sample contamination is virtually eliminated.

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.

Nitrogen function of aluminum-nitride codoped ZnO films deposited using cosputter system

2009 ◽  
Vol 24 (7) ◽  
pp. 2252-2258 ◽  
Author(s):  
Li-Wen Lai ◽  
Jheng-Tai Yan ◽  
Chia-Hsun Chen ◽  
Li-Ren Lou ◽  
Ching-Ting Lee
Keyword(s):  
Low Temperature ◽  
Oxygen Vacancies ◽  
Carrier Lifetime ◽  
Nitrogen Atmosphere ◽  
Zno Films ◽  
Deposition Condition ◽  
Time Resolved ◽  
Sapphire Substrates ◽  
Crystallographic Structures ◽  
Time Resolved Photoluminescence

AlN codoped ZnO films were deposited on sapphire substrates at low temperature using a cosputter system under various N2/(N2 + Ar) flow ratios. To investigate the nitrogen function, the ratio of nitrogen ambient was varied during cosputtering. AlN codoped ZnO films with various crystallographic structures and bonding configurations were measured. With an adequate nitrogen atmosphere deposition condition and postannealing temperature at 450 °C, the p-type conductive behaviors of AlN codoped ZnO films were achieved due to the formation of Zn–N bonds. According to the low-temperature photoluminescence spectra, the binding energy (EA) of 0.16 eV for N acceptors can be calculated. Using time-resolved photoluminescence measurement, the carrier lifetime in AlN codoped ZnO films increases due to the reduction of oxygen vacancies caused by the occupation of adequate nitrogen atoms.

Semiconductor Nanostructures for Infrared Applications

2004 ◽  
Vol 99-100 ◽  
pp. 99-108
Author(s):  
N. Žurauskienė ◽  
S. Ašmontas ◽  
A. Dargys ◽  
J. Kundrotas ◽  
G. Janssen ◽  
...  
Keyword(s):  
Quantum Wells ◽  
High Energy ◽  
Alpha Particles ◽  
Infrared Photodetector ◽  
Time Resolved ◽  
Carrier Lifetimes ◽  
Quantum Dot Infrared Photodetector ◽  
Optically Detected ◽  
Microwave Excitation ◽  
Time Resolved Photoluminescence

We present the results of time-resolved photoluminescence (TRPL) and optically detected microwave resonance (ODMR) spectroscopy investigations of semiconductor quantum dots and quantum wells. The ODMR spectra of InAs/GaAs QDs were detected via modulation of the total intensity of the QDs emission induced by 95 GHz microwave excitation and exciton fine structure was studied. Very long life times (up to 10 ns) of photoexcited carriers were observed in this system using TRPL at low temperatures and excitation intensities promising higher responsitivity of such QDs for quantum dot infrared photodetector development. The effects of proton and alpha particles irradiation on carrier dynamics were investigated on different InGaAs/GaAs, InAlAs/AlGaAs and GaAs/AlGaAs QD and QW systems. The obtained results demonstrated that carrier lifetimes in the QDs are much less affected by proton irradiation than that in QWs. A strong influence of irradiation on the PL intensity was observed in multiple QWs after high-energy alpha particles irradiation.

Low temperature time resolved photoluminescence in ordered and disordered Cu2ZnSnS4 single crystals

2017 ◽  
Vol 508 ◽  
pp. 47-50 ◽  
Author(s):  
Taavi Raadik ◽  
Jüri Krustok ◽  
M. Kauk-Kuusik ◽  
K. Timmo ◽  
M. Grossberg ◽  
...  
Keyword(s):  
Low Temperature ◽  
Single Crystals ◽  
Time Resolved ◽  
Time Resolved Photoluminescence ◽  
Temperature Time

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.

Investigation of the Electronic Structure of the UD-4 Defect in 4H-SiC by Optical Techniques

2006 ◽  
Vol 527-529 ◽  
pp. 461-464 ◽  
Author(s):  
Aurelie Thuaire ◽  
Anne Henry ◽  
Björn Magnusson ◽  
Peder Bergman ◽  
W.M. Chen ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Electronic Structure ◽  
Low Temperature ◽  
Deep Level ◽  
Temperature Dependent ◽  
Deep Level Defect ◽  
Time Resolved ◽  
Optical And Electronic Properties ◽  
Time Resolved Photoluminescence ◽  
Temperature Dependent Photoluminescence

A detailed investigation of the optical and electronic properties of the deep-level defect UD-4 is reported. This defect has recently been observed in 4H semi-insulating silicon carbide, but has hardly been studied yet. Both low temperature and temperature-dependent photoluminescence were collected from the defect. Zeeman spectroscopy measurements were performed as well as time-resolved photoluminescence.

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