Internal Schottky barriers in semiconductors

1982 ◽  
Vol 60 (3) ◽  
pp. 269-272 ◽  
Author(s):  
F. L. Weichman

We discuss the effect on the electrical conductivity of a semiconductor if small metal inclusions are formed within the bulk of the semiconductor where the metal to semiconductor contact is a rectifying one. We find that the depletion layers formed inside the material can dominate the conduction process and give rise to conditions similar to that of a highly compensated semiconductor with highly variable activation energy. Some of the predictions of the model are compared to observed facts in cuprous oxide and are shown to be consistent with observation. The expected behaviour of a semiconductor with internal injecting contacts is also briefly discussed.

2018 ◽  
Vol 31 (3) ◽  
pp. 20
Author(s):  
Sarmad M. M. Ali ◽  
Alia A.A. Shehab ◽  
Samir A. Maki

In this study, the ZnTe thin films were deposited on a glass substrate at a thickness of 400nm using vacuum evaporation technique (2×10-5mbar) at RT. Electrical conductivity and Hall effect measurements have been investigated as a function of variation of the doping ratios (3,5,7%) of the Cu element on the thin ZnTe films. The temperature range of (25-200°C) is to record the electrical conductivity values. The results of the films have two types of transport mechanisms of free carriers with two values of activation energy (Ea1, Ea2), expect 3% Cu. The activation energy (Ea1) increased from 29meV to 157meV before and after doping (Cu at 5%) respectively. The results of Hall effect measurements of ZnTe , ZnTe:Cu films show that all films were (p-type), the carrier concentration (1.1×1020 m-3) , Hall mobility (0.464m2/V.s) for pure ZnTe film, increases the carrier concentration (6.3×1021m-3) Hall mobility (2m2/V.s) for doping (Cu at 3%) film, but  decreases by increasing Cu concentration.


Ionics ◽  
1995 ◽  
Vol 1 (5-6) ◽  
pp. 488-490 ◽  
Author(s):  
Y. Tsur ◽  
I. Riess

2019 ◽  
Vol 74 (9) ◽  
pp. 739-742
Author(s):  
Elena V. Nikolaeva ◽  
Andrey L. Bovet ◽  
Irina D. Zakiryanova

AbstractThe electrical conductivity of molten ternary alkali carbonate eutectic, coexisting with MgO particles, has been investigated. The conductivity was measured by the AC impedance method. The apparent activation energy ΔEa increased with the MgO content. This fact can be attributed to the effect of the solid phase. The specific conductivity of those systems could not be described using the Maxwell model over the solvation process of the carbonate ions on the particles of the magnesium oxide.


2019 ◽  
Vol 85 (5) ◽  
pp. 60-68
Author(s):  
Yuliay Pogorenko ◽  
Anatoliy Omel’chuk ◽  
Roman Pshenichny ◽  
Anton Nagornyi

In the system RbF–PbF2–SnF2 are formed solid solutions of the heterovalent substitution RbxPb0,86‑xSn1,14F4-x (0 < x ≤ 0,2) with structure of β–PbSnF4. At x > 0,2 on the X-ray diffractograms, in addition to the basic structure, additional peaks are recorded that do not correspond to the reflexes of the individual fluorides and can indicate the formation of a mixture of solid solutions of different composition. For single-phase solid solutions, the calculated parameters of the crystal lattice are satisfactorily described by the Vegard rule. The introduction of ions of Rb+ into the initial structure leads to an increase in the parameter a of the elementary cell from 5.967 for x = 0 to 5.970 for x = 0.20. The replacement of a part of leads ions to rubium ions an increase in electrical conductivity compared with β–PbSnF4 and Pb0.86Sn1.14F4. Insignificant substitution (up to 3.0 mol%) of ions Pb2+ at Rb+ at T<500 K per order of magnitude reduces the conductivity of the samples obtained, while the nature of its temperature dependence is similar to the temperature dependence of the conductivity of the sample β-PbSnF4. By replacing 5 mol. % of ions with Pb2+ on Rb+, the fluoride ion conductivity at T> 450 K is higher than the conductivity of the initial sample Pb0,86Sn1,14F4 and at temperatures below 450 K by an order of magnitude smaller. With further increase in the content of RbF the electrical conductivity of the samples increases throughout the temperature range, reaching the maximum values at x≥0.15 (σ573 = 0.34–0.41 S/cm, Ea = 0.16 eV and σ373 = (5.34–8.16)•10-2 S/cm, Ea = 0.48–0.51 eV, respectively). In the general case, the replacement of a part of the ions of Pb2+ with Rb+ to an increase in the electrical conductivity of the samples throughout the temperature range. The activation energy of conductivity with an increase in the content of RbF in the low-temperature region in the general case increases, and at temperatures above 400 K is inversely proportional decreasing. The nature of the dependence of the activation energy on the concentration of the heterovalent substituent and its value indicate that the conductivity of the samples obtained increases with an increase in the vacancies of fluoride ions in the structure of the solid solutions.


2011 ◽  
Vol 8 (1) ◽  
pp. 168-174
Author(s):  
Baghdad Science Journal

The present studies are focused on the modification of the properties of epoxy resin with different additives namely aluminum, copper by preparing of composites systems with percentage (20%, 40% and 50%) of the above additives. The experimental results show that the D.C of conductivity on wt% filler content at ( 293-413 ) K electrical conductivity of all above composites increased with temperature for composites with filler contact and find the excellent electrical conductivity of copper and lie between (2.6*10-10 - 2.1*10-10)?.cm . The activation energy of the electrical conductivity is determined and found to decrease with increasing the filler concentration.


2005 ◽  
Vol 862 ◽  
Author(s):  
Steve Reynolds ◽  
Vlad Smirnov ◽  
Friedhelm Finger ◽  
Charlie Main ◽  
Reinhard Carius

AbstractChanges in the electrical conductivity of thin (< 300 nm) silicon films following prolonged exposure to atmosphere, are reported. Both reversible (by annealing at 150 °C under vacuum) and irreversible (annealing-resistant) effects are found to occur, which are larger in thinner films. The conductivity prefactor and thermal activation energy obey the Meyer-Neldel rule, although detailed behaviour depends on film thickness and microstructure. Irreversible changes may result from oxidation of thinner, more porous films, with water and/or oxygen adsorption and desorption responsible for reversible changes. The need to identify and account for these effects when discussing and formulating transport mechanisms in these materials is underlined.


1983 ◽  
Vol 38 (5) ◽  
pp. 593-594 ◽  
Author(s):  
W. D. Basler ◽  
I. V. Murin ◽  
S. V. Chernov

The diffusion of fluorine in KSn2F5 has been studied by T1 and T2 relaxation time measurements of 19F NMR (200-500 K) and pulsed magnetic Field gradient tech­niques (390-480 K). Near 423 K a sharp transition into the superionic state has been found, the fluorine diffusion increasing by a factor of 4 within a range of 3 K. Conduc­tivity measurements only show a change in the activation energy.


Open Physics ◽  
2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Ihor Studenyak ◽  
Yuriy Neimet ◽  
Csaba Cserháti ◽  
Sándor Kökényesi ◽  
Edvardas Kazakevičius ◽  
...  

AbstractStructural studies of (Ag3AsS3)x (As2S3)1−x chalcogenide superionic glasses in the compositional range x = 0.3–0.9 were performed by scanning electron microscopy. Temperature and compositional dependences of transmission coefficient, electrical conductivity, and activation energy were investigated


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