Temperature Dependence of a-Si:H Nip Diodes

1991 ◽  
Vol 219 ◽  
Author(s):  
C. van Berkel ◽  
M. J. Powell ◽  
I. D. French
Keyword(s):  
Activation Energy ◽  
Space Charge ◽  
Temperature Dependence ◽  
Quality Factor ◽  
Physical Interpretation ◽  
Linear Dependence ◽  
Space Charge Limited Current ◽  
Temperature Expansion ◽  
First Order ◽  
Hole Recombination

ABSTRACTWe analyse the temperature dependence of the forward characteristics of a-Si:H nip diodes, which are characterised by a well defined exponential region at low bias and space charge limited current at higher bias. At each bias, the temperature dependence of the diodes shows a well defined activation energy and a linear dependence on bias exists for both the activation energy and exponential prefactor. We describe these phenomena with a first order temperature expansion of the diode quality factor n and present a physical interpretation in terms of electron and hole recombination in the i-layer.

Electrical Properties of Fluorine Doped Diamond Like Carbon

2006 ◽  
Vol 514-516 ◽  
pp. 53-57
Author(s):  
Simone C. Trippe ◽  
Joana Catarina Madaleno ◽  
Luiz Pereira
Keyword(s):  
Activation Energy ◽  
Electrical Properties ◽  
Space Charge ◽  
Potential Barrier ◽  
Diamond Like Carbon ◽  
Fluorine Concentration ◽  
Space Charge Limited Current ◽  
Differential Conductivity ◽  
Concentration Increase ◽  
Trap Energy

In this work fluorinated Diamond Like Carbon (DLC) films have been grown with different CF4 concentrations and have been studied by electrical DC measurements in a temperature range from 30 to 300 K. It was found that the samples grown with lower CF4 concentration show a small rectification, with a potential barrier lower than 0.3 V. The bulk conduction shows a trapcontrolled Space Charge Limited Current (SCLC), with characteristic trap energy between 0.08 and 0.13 eV, confirmed by the differential conductivity analysis. The activation energy (ranging from 50 to 140 meV) is also dependent on the sample fluorine concentration, decreasing with the fluorine concentration increase.

Vulcanization of Elastomers. 12. Perbunan with Thiuram Monosulfide and Sulfur. I

1959 ◽  
Vol 32 (1) ◽  
pp. 128-138 ◽  
Author(s):  
Walter Scheele ◽  
Horst-Eckart Toussaint
Keyword(s):  
Activation Energy ◽  
Natural Rubber ◽  
Temperature Dependence ◽  
Induction Period ◽  
Rate Constants ◽  
The Other ◽  
Tetramethylthiuram Disulfide ◽  
First Order ◽  
The One ◽  
Limiting Value

Abstract The vulcanization of Perbunan 2818 by tetramethylthiuram monsulfide plus sulfur (1 mole monosulfide per gram-atom S) was thoroughly studied. The following results were shown: The limiting value for dithiocarbamate formation is 66 mole per cent of the initial thiuram monosulfide, indicating a two-thirds transformation. The limiting value is practically independent of temperature. The formation of dithiocarbamate can be described as a reaction of the first order. The formation of dithiocarbamate is characterized by an induction period which grows longer with lowering of the temperature, and at 100° C it amounts to about 100 minutes. The rate constants for dithiocarbamate formation were calculated, and it was shown that they were practically the same as those for the vulcanization of Perbunan with tetramethylthiuram disulfide. The activation energies as derived from the temperature dependence of the rate constants for dithiocarbamate formation in the vulcanization of Perbunan by thiuram monosulfide plus sulfur on the one hand and with thiuram disulfide on the other, are only very slightly different and are practically the same as the activation energy for dithiocarbamate formation during the vulcanization of natural rubber with thiuram monosulfide plus sulfur. The results were thoroughly discussed in light of the present conceptions of the course of thiuram vulcanizations.

Vulcanization of Elastomers. 21. Vulcanization of Natural Rubber with Thiuram Disulfides. VI

1959 ◽  
Vol 32 (2) ◽  
pp. 566-576
Author(s):  
Walter Scheele ◽  
Klaus Hummel
Keyword(s):  
Activation Energy ◽  
Natural Rubber ◽  
Temperature Dependence ◽  
Sulfur Content ◽  
Rate Constants ◽  
Order Reaction ◽  
First Order Reaction ◽  
Kcal Mole ◽  
First Order ◽  
Limiting Value

Abstract Bound sulfur in a pure thiuram vulcanizate increases relatively rapidly at first at all temperatures, reaches a poorly defined maximum at about 27 to 30%, independent of temperature, and then recedes slightly to reach a limiting value of 25% also independent of temperature, based on the original thiuram disulfide. The rise in sulfur content at the start points to a temperature-independent limiting value of 33%. It is shown that the combination of sulfur in this region initially follows a first order reaction, and goes at the same rate as the reduction in concentration of thiuram disulfide. It can be seen from the above that sulfur may be combined in thiuram vulcanization without simultaneous crosslinking. The dithiocarbamate formation increases rapidly in the region of longer vulcanization times, after the maximum in bound sulfur has been reached, without further combination of sulfur with the vulcanizate. The rate constants for thiuram decrease, for dithiocarbamate increase and for sulfur combination were calculated. The temperature dependence of each of these reactions has practically the same activation energy, 23 kcal/mole. The bound sulfur content of the vulcanizates in pure thiuram vulcanizations is no criterion of the state of vulcanization.

Temperature dependence of the creatine kinase reaction measured in rat brain in vivo by 31P NMR saturation transfer

1999 ◽  
Vol 77 (11) ◽  
pp. 1887-1891
Author(s):  
Richard Buist ◽  
Scott Kroeker ◽  
James Peeling
Keyword(s):  
Activation Energy ◽  
Creatine Kinase ◽  
Temperature Dependence ◽  
Rat Brain ◽  
Order Rate Constant ◽  
Saturation Transfer ◽  
Kinase Activation ◽  
First Order ◽  
Creatine Kinase Reaction

Creatine kinase (CK) catalyzes the reversible phosphorylation of MgADP by phosphocreatine and thus regulates cellular concentrations of ADP and ATP. The temperature dependence of this reaction has been determined in rat brain in vivo between 30 and 40°C using 31P NMR saturation transfer measurements. The pseudo-first-order rate constant for the forward CK reaction, kf, varies little with temperature over this range, with an apparent activation energy Ea = 14.2 ± 4.9 kJ/mol. This is considerably lower than the values of Ea for isolated CK enzymes. However, when changes in [MgADP] and [H+] with temperature are considered, a substrate concentration-independent value of Ea = 65.3 ± 9.7 kJ/mol is obtained for the maximum forward reaction velocity Vmax. This agrees well with literature values for the isolated brain-type isoform of CK.Key words: creatine kinase, activation energy, temperature, brain, rat.

Space-charge-limited current in GaAs

1966 ◽  
Vol 2 (7) ◽  
pp. 282
Author(s):  
A.M. Phahle ◽  
K.C. Kao ◽  
J.H. Calderwood
Keyword(s):  
Space Charge ◽  
Space Charge Limited Current ◽  
Limited Current ◽  
Space Charge Limited
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