Activation energies for ultrahigh purity YBCO single crystals

1998 ◽  
Vol 11 (10) ◽  
pp. 1105-1111 ◽  
Author(s):  
J W Cochrane ◽  
G J Russell
Keyword(s):  
Single Crystals ◽  
Activation Energies

Temperature dependence of the optical properties in p-Cd0.96Zn0.04Te single crystals

2001 ◽  
Vol 16 (8) ◽  
pp. 2196-2199 ◽  
Author(s):  
H. Y. Lee ◽  
T. W. Kang ◽  
T. W. Kim
Keyword(s):  
Optical Properties ◽  
Temperature Dependence ◽  
Single Crystals ◽  
Reasonable Agreement ◽  
Theoretical Calculations ◽  
Optoelectronic Devices ◽  
Activation Energies ◽  
Acoustic Parameters ◽  
Longitudinal Acoustic ◽  
Pl Spectra

Photoluminescence (PL) measurements were performed on p-Cd0.96Zn0.04Te single crystals to investigate the dependence of the excitons on temperature. The activation energies and the longitudinal acoustic parameters of the excitons were determined from the temperature dependence of the PL spectra and were in reasonable agreement with the theoretical calculations. These results can help improve understanding for the application of p-CdxZn1–xTe single crystals in optoelectronic devices.

Thermoluminescence study on TlGaSSe layered single crystals

2014 ◽  
Vol 28 (16) ◽  
pp. 1450133 ◽  
Author(s):  
Serdar Delice ◽  
Nizami M. Gasanly
Keyword(s):  
Single Crystals ◽  
Heating Rate ◽  
Thermal Quenching ◽  
Activation Energies ◽  
Temperature Peak ◽  
Heating Rates ◽  
Quenching Effect ◽  
Defect Centers ◽  
General Order ◽  
Maximum Temperatures

The defect centers in TlGaSSe single crystals have been investigated by performing thermoluminescence (TL) measurements with various heating rates between 0.5 K/s and 1.0 K/s in the temperature range of 10–180 K. The TL spectra, with peak maximum temperatures at 39 K and 131 K, revealed the existences of two defect levels. Curve fitting, initial rise and peak shape methods were used to determine the activation energies of two defect centers. The experimental results also showed that the trapping process was dominated by second-order kinetics for the trap related with low temperature peak while the general order (mixed order) kinetics was dominant for the trap donated to high temperature peak. Furthermore, heating rate dependences and traps distributions were studied for two defect centers separately. Thermal quenching effect dominates the behavior of these defects as the heating rate is increased. Also, quasi-continuous distributions were established with the increase of the activation energies from 16 meV to 27 meV and from 97 meV to 146 meV for the traps associated with the peaks observed at low and high temperatures, respectively.

scholarly journals Электрически активные состояния захвата и переноса заряда, обусловливающие медленную рекомбинацию в кристаллах бромида таллия при низких температурах

2018 ◽  
Vol 52 (2) ◽  
pp. 171
Author(s):  
В. Кажукаускас ◽  
Р. Гарбачаускас ◽  
С. Савицки
Keyword(s):  
Activation Energy ◽  
Electric Field ◽  
Single Crystals ◽  
Applied Electric Field ◽  
Thermal Activation ◽  
Thermal Quenching ◽  
Activation Energies ◽  
Trap States ◽  
Optical Generation ◽  
Stockbarger Method

AbstractTlBr single crystals grown by the Bridgman–Stockbarger method are studied. It is established that frozen-conductivity effects manifest themselves under interband excitation by light at temperatures below 200 K. Herewith, clearly pronounced superlinear dependences of the induced photoconductivity on the strength of the applied electric field manifest themselves. The results of studying thermally stimulated conductivity evidence that these phenomena can be associated with the filling of trap states with thermal activation energies of 0.08–0.12 eV. This state can be removed due to thermal quenching at temperatures of ≳180 K because of the emptying of energy states with an activation energy of 0.63–0.65 eV filled after optical generation.

Deep-Level Defects in Nitrogen-Doped 6H-SiC Grown by PVT Method

2008 ◽  
Vol 1069 ◽  
Author(s):  
Pawel Kaminski ◽  
Michal Kozubal ◽  
Krzysztof Grasza ◽  
Emil Tymicki
Keyword(s):  
Single Crystals ◽  
Defect Structure ◽  
Deep Level ◽  
Nitrogen Concentration ◽  
Activation Energies ◽  
Electron Traps ◽  
Nitrogen Doped ◽  
Significant Change

ABSTRACTAn effect of the nitrogen concentration on the concentrations of deep-level defects in bulk 6H-SiC single crystals is investigated. Six electron traps labeled as T1A, T1B, T2, T3, T4 and T5 with activation energies of 0.34, 0.40, 0.64, 0.67, 0.69, and 1.53 eV, respectively, were revealed. The traps T1A (0.34 eV) and T1B (0.40 eV), observed in the samples with the nitrogen concentration ranging from ∼2×1017 to 5×1017 cm−3, are attributed to complexes formed by carbon vacancies located at various lattice sites and carbon antisites. The concentrations of traps T2 (0.64 eV) and T3 (0.67 eV) have been found to rise from ∼5×1015 to ∼1×1017 cm−3 with increasing the nitrogen concentration from ∼2×1017 to ∼2.0×1018 cm−3. These traps are assigned to complexes involving silicon vacancies occupying hexagonal and quasi-cubic sites, respectively, and nitrogen atoms. The trap T4 (0.69 eV) concentration also substantially rises with increasing the nitrogen concentration and it is likely to be related to complexes formed by carbon antisites and nitrogen atoms. The midgap trap T5 (1.53 eV) is presumably associated with vanadium contamination. The presented results show that doping with nitrogen involves a significant change in the defect structure of 6H-SiC single crystals.

scholarly journals Электропроводность монокристаллов MnGaInSе-=SUB=-4-=/SUB=- на переменном токе

2020 ◽  
Vol 46 (11) ◽  
pp. 19
Author(s):  
Н.Н. Нифтиев ◽  
Ф.М. Мамедов ◽  
М.Б. Мурадов
Keyword(s):  
Electrical Conductivity ◽  
Single Crystal ◽  
Frequency Dependence ◽  
Electric Current ◽  
Single Crystals ◽  
Activation Energies ◽  
Temperature Range ◽  
Temperature Dependences ◽  
Alternating Electric Current

The results of studying the frequency and temperature dependences of the electrical conductivity of MnGaInSe4 single crystals on alternating electric current are presented. It was found that in the temperature range of 295.5–360 K at frequencies of 2•104–106 Hz, the regularity σ ∼ fS (0.1≤ s≤1.0) holds for electrical conductivity. It is shown that in the MnGaInSe4 single crystal the frequency dependence of electrical conductivity can be explained using the multiplet model, and the conductivity in these single crystals is characterized by a band-hop mechanism. Based on the dependences log σ ∼ 103/T, the activation energies are determined.

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