scholarly journals TEMPERATURE DEPENDENCE OF THERMAL EMISSION RATE IN Ce:KNSBN

1997 ◽  
Vol 46 (5) ◽  
pp. 915
Author(s):  
JI XUAN-MANG ◽  
AN YU-YING ◽  
LIU JIN-SONG
Keyword(s):  
Temperature Dependence ◽  
Emission Rate ◽  
Thermal Emission ◽  
Thermal Emission Rate

Deep Defect Relaxation in Hydrogenated Amorphous Silicon: New Experimental Evidence and Implications

1998 ◽  
Vol 507 ◽  
Author(s):  
J. David Cohen ◽  
Fan Zhong ◽  
Daewon Kwon ◽  
C.-C. Chen
Keyword(s):  
Fermi Level ◽  
Emission Rate ◽  
Thermal Emission ◽  
Hydrogenated Amorphous Silicon ◽  
Depletion Region ◽  
Time Resolved ◽  
Apparent Shift ◽  
Hydrogenated Amorphous ◽  
Defect Relaxation ◽  
Thermal Emission Rate

ABSTRACTWe review modulated photocurrent experiments which indicate that thermal emission rate for Do defects in intrinsic samples varies in response to changes in the Fermi-level or quasi-Fermi position. This apparent shift in energy threshold is confirmed using time resolved sub-band-gap spectroscopy. We also demonstrate that such a variation of emission rate with changes in the Fermi-level position, if present within the depletion region near a barrier junction, is consistent with the details of the temperature dependence of the junction capacitance in intrinsic samples.

Application of Computational Intelligence to Investigation of Defect Centers in Semi-Insulating Materials by Photoinduced Transient Spectroscopy

2007 ◽  
Vol 994 ◽  
Author(s):  
Pawel Kaminski ◽  
Stanislaw Jankowski ◽  
Roman Kozlowski ◽  
Janusz Bedkowski
Keyword(s):  
Computational Intelligence ◽  
Emission Rate ◽  
Thermal Emission ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Inverse Laplace Transform ◽  
Model Complexity ◽  
Support Vector ◽  
Defect Centers ◽  
Temperature Dependences

AbstractA computational intelligence algorithm has been applied to extracting trap parameters from the photocurrent relaxation waveforms recorded at the temperature range of 20-320 K for semi-insulating (SI) InP samples. Using the inverse Laplace transform procedure, the spectral surfaces, visualized in the three dimensional space as functions of temperature and emission rate, are calculated. The processes of thermal emission of charge carriers from defect centers manifest themselves as the sharp folds on the spectral surface. Using a set of Gaussian functions, the approximating surface is created and the ridgelines of the folds, giving the temperature dependences of the emission rate for the detected traps, are determined. The approximation is performed using the support vector machine (SVM) algorithm which allows for trading off between the model complexity and fitting accuracy. The new approach is exemplified by comparing the defect structure of SI InP wafers after annealing in iron phosphide and pure phosphorous atmospheres.

Temperature Dependence of the Local Field Effect in YAG:Ce3+ Nanocomposites

Nanoscale ◽  
2021 ◽  
Author(s):  
Anjun Huang ◽  
Konstantin K Pukhov ◽  
Ka Leung Wong ◽  
Peter A Tanner
Keyword(s):  
Electric Field ◽  
Temperature Dependence ◽  
Spontaneous Emission ◽  
Local Field ◽  
Field Effect ◽  
Emission Rate ◽  
Spontaneous Emission Rate ◽  
Local Field Effect

The spontaneous emission rate (SER) of a chromophore in a nanoparticle (NP) is determined by the modification of the electric field by its environment. Previous studies of this local field...

The Thermal Emission of Iodine

1974 ◽  
Vol 52 (19) ◽  
pp. 1862-1871
Author(s):  
J. David Brown ◽  
George Burns
Keyword(s):  
Experimental Data ◽  
Shock Wave ◽  
Temperature Dependence ◽  
Electronic State ◽  
Reasonable Agreement ◽  
Thermal Emission ◽  
Electronic States ◽  
Excited Electronic States ◽  
Calculated Temperature ◽  
Calculated Temperature Dependence

The temperature dependence of emission from iodine, heated in a shock wave to 1000 K–2000 K, has been measured at 4550, 5550, 6950, 7550, and 7820 Å. Preliminary measurements of the emission at 6380 Å were also made. The temperature dependence of the emission was calculated at these wavelengths for transitions to the ground electronic state X(1Σg+) of iodine from the excited electronic states, A(3Π1u), (1Π1u), and [Formula: see text]. The calculated results are in a reasonable agreement with experimental data. For the banded emission due to the B → X transition, a theory of the temperature dependence of emission was developed. At 6950, 7550, and 7820 Å, the results of this theory agree with the experimental data thus identifying the B → X transition as the source of emission at these wavelengths. The temperature dependence of emission at 4550 Å is consistent with calculated temperature dependence for either (1Π1u) → X or [Formula: see text] transitions. The temperature dependence of the emission at 5550 Å is consistent with calculated temperature dependence for the above two transitions, as well as for the A(3Π1u) → X transition.

Carrier Hopping and Relaxation in InAs/GaAs Quantum Dot Heterostructures

2014 ◽  
Vol 875-877 ◽  
pp. 9-13
Author(s):  
Ya Fen Wu ◽  
Jiunn Chyi Lee
Keyword(s):  
Energy Level ◽  
Quantum Dot ◽  
Temperature Dependence ◽  
Thermal Emission ◽  
Carrier Dynamics ◽  
Photoluminescence Spectra ◽  
Discrete Energy ◽  
Discrete Energy Level ◽  
Size Uniformity ◽  
Gaas Quantum Dot

We investigate the effect of carrier dynamics on the temperature dependence of photoluminescence spectra from InAs/GaAs quantum dot heterostructures with different dot size uniformity. Intersublevel relaxation lifetimes and carrier transferring mechanisms are simulated using a model based on carriers relaxing and thermal emission of each discrete energy level in the quantum dot system. Calculated relaxation lifetimes are decreasing with temperature and have larger values for sample with lower dot size uniformity. In the quantitative discussion of carrier dynamics, the influence of thermal redistribution on carriers relaxing process of quantum dot system is demonstrated by our model.

scholarly journals Volcanic SO<sub>2</sub> and SiF<sub>4</sub> visualization using 2-D thermal emission spectroscopy – Part 2: Wind propagation and emission rates

2013 ◽  
Vol 6 (1) ◽  
pp. 47-61 ◽  
Author(s):  
A. Krueger ◽  
W. Stremme ◽  
R. Harig ◽  
M. Grutter
Keyword(s):  
Wind Field ◽  
Emission Spectroscopy ◽  
Emission Rate ◽  
Thermal Emission ◽  
Diagnostic Tools ◽  
Volcanic Plume ◽  
Reconstruction Method ◽  
Emission Rates ◽  
Reconstruction Methods ◽  
Thermal Emission Spectroscopy

Abstract. A technique for measuring two-dimensional (2-D) plumes of volcanic gases with thermal emission spectroscopy was described in Part 1 by Stremme et al. (2012a). In that paper the instrumental aspects as well as retrieval strategies for obtaining the slant column images of SO2 and SiF4, as well as animations of particular events observed at the Popocatépetl volcano, were presented. This work focuses on the procedures for determining the propagation speed of the gases and estimating an emission rate from the given image sequences. A 2-D column density distribution of a volcanic gas, available as time-consecutive frames, provides information of a projected wind field and the average velocity at which the volcanic plume is propagating. This information is valuable since the largest uncertainties when calculating emission rates of the gases using remote sensing techniques arise from propagation velocities which are often inadequately assumed. The presented reconstruction method solves the equation of continuity as an ill-posed problem using mainly a Tikhonov-like regularisation. It is observed from the available data sets that if the main direction of propagation is perpendicular to the line-of-sight, the algorithm works well for SO2, which has the strongest signals, and also for SiF4 in some favourable cases. Due to the similarity of the algorithm used here with the reconstruction methods used for profile retrievals based on optimal estimation theory, diagnostic tools like the averaging kernels can be calculated in an analogous manner and the information can be quantified as degrees of freedom. Thus, it is shown that the combination of wind field and column distribution of the gas plume can provide the emission rate of the volcano both during day and night.

Compensating defect centres in semi-insulating 6H-SiC

2009 ◽  
Vol 17 (1) ◽  
pp. 1-7 ◽  
Author(s):  
P. Kamiński ◽  
R. Kozłowski ◽  
M. Miczuga ◽  
M. Pawłowski ◽  
M. Kozubal ◽  
...  
Keyword(s):  
Point Defects ◽  
Emission Rate ◽  
Thermal Emission ◽  
Charge Compensation ◽  
Charge Carriers ◽  
Two Dimensional ◽  
New Approach ◽  
Temperature Dependences ◽  
Transient Spectroscopy ◽  
Defect Centres

AbstractPhotoinduced transient spectroscopy (PITS) has been applied to study electronic properties of point defects associated with charge compensation in semi-insulating (SI) 6H-SiC substrates. The photocurrent relaxation waveforms were digitally recorded in a wide temperature range of 20–800 K and in order to extract the parameters of defect centres, a two-dimensional analysis of the waveforms as a function of time and temperature has been implemented. As a result, the processes of thermal emission of charge carriers from defect centres were seen on the spectral surface as the folds, whose ridgelines depicted the temperature dependences of emission rate for detected defect centres. The new approach was used to compare the defect levels in vanadium-doped and vanadium-free (undoped) SI 6H-SiC wafers.

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