Conductivity and Thermo-Electric Effect in Cuprous Oxide

Makinson’s extension of Wilson’s treatment of the second-order effects in metals is used to derive an expression for the contribution of the lattice current to the thermo-electric power of metals at those temperatures where electron-phonon scattering predominates. It is found that in this temperature region one may expect the thermo-electric effect to show a sign opposite to the one which follows from the simple electron theory of metals. This is because the term due to the departure from equilibrium of the lattice distribution is larger than the usual term and is of opposite sign. If the temperature is greatly decreased or increased, the usual term predominates. The effect discussed may have a bearing on the behaviour of the thermo-electric power of the alkali metals, although it cannot explain this behaviour completely.

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A Study of Bismuth Induced Levels in CZT Using TEES/TSC

MRS Proceedings ◽

10.1557/proc-1164-l10-02 ◽

2009 ◽

Vol 1164 ◽

Author(s):

Raji Soundararajan ◽

Kelly A. Jones ◽

Santosh Swain ◽

Kelvin Lynn

Keyword(s):

Cross Section ◽

Ionization Energy ◽

Radiation Detector ◽

Radiation Detectors ◽

Thermal Ionization ◽

Thermo Electric ◽

High Electrical Resistivity ◽

Deep Donor ◽

Defect Levels ◽

Electric Effect

AbstractConsidering the desirable effects of doping CdTe with heavy elements like Bi, we have grown a Cadmium Zinc Telluride (Zn=10%) ingot with Bi (doping levels ∼1014 to 1015 at/cm3) as the heavy element dopant for use as a room temperature radiation detector, using the Bridgman method. In-spite of a high bulk resitivity (∼1010?cm), and the ability to hold high electric field (>2000 V/cm), these lightly doped crystals had a poor spectral resolution for the Co-57 photo peaks and ??e measurements were so low that these measurement were not reliable. Thermo electric effect spectroscopy (TEES) and thermally stimulated current (TSC) experiments on samples C and F (single crystals close to the tip and the heel of the ingot respectively) have revealed various defect levels in the band gap. Among these defect levels, we have identified and characterized two Bi-related deep levels namely a deep donor level L5 (thermal ionization energy: 0.33[5] to 0.39[5] eV and trap cross-section: 7.1[5] × 10-17 to 2.54 [5] × 10-16 cm2), and a deep acceptor level L8 (thermal ionization energy of 0.82 [5] eV and trap cross-section of 2.59 [5] × 10-12 cm2). These levels were responsible for the observed high electrical resistivity (∼1010 ?*cm) in the CdZnTe samples. From a comparison to studies on Bi doped CdTe samples, level L8 was tentatively associated with the (0/-) transition of (BiCd- - OTe) complex, however is still under study. Since these defect levels also act as trapping centers for charge carriers, in spite of the semi-insulating behavior the samples are poor radiation detectors.

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Convection and solidification influenced by thermo-electric effect

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/117/1/012051 ◽

2016 ◽

Vol 117 ◽

pp. 012051

Author(s):

J Wang ◽

G S Abou-Jaoude ◽

O Budenkova ◽

G Reinhart ◽

N Mangelinck ◽

...

Keyword(s):

Thermo Electric ◽

Electric Effect

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ON THE NATURE OF THE TRANSVERSE THERMO-MAGNETIC EFFECT AND THE TRANSVERSE THERMO-ELECTRIC EFFECT IN CRYSTALS

Papers 59-93 ◽

10.4159/harvard.9780674287822.c26 ◽

2014 ◽

Author(s):

P. W. Bridgman

Keyword(s):

Magnetic Effect ◽

Thermo Electric ◽

Electric Effect

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The semiconducting properties of cuprous oxide

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1952.0216 ◽

1952 ◽

Vol 215 (1122) ◽

pp. 353-370 ◽

Cited By ~ 23

Keyword(s):

Thermoelectric Power ◽

Cuprous Oxide ◽

Ambient Pressure ◽

Activation Energies ◽

Satisfactory Explanation ◽

Thermo Electric ◽

A Value ◽

Semiconducting Properties ◽

Conductivity Curve ◽

Positive Hole

A procedure has been developed for preparing reproducible specimens of cuprous oxide at the oxygen-poor limit of its composition range. The electrical conductivity and thermoelectric power of such specimens were measured simultaneously, and related to temperature within the range 20 to 1030° C. The conductivity-temperature curve consists of two limbs, the slopes of which correspond to activation energies of 0.300 and 1.04 eV respectively. The relation between thermoelectric power and temperature also falls into two segments, the temperature of discontinuity agreeing closely with the break in the conductivity curve. Below 355° C the thermo-electric power is quite independent of temperature and has a value 1.64 mV deg. -1 . Above 355° C the thermoelectric power decreases with rise in temperature; its sign does not change, but remains characteristic of a positive-hole conductor up to the highest temperatures investigated. The effect of oxygenating cuprous oxide of limiting composition has also been studied. With an ambient pressure of 9 mm oxygen the activation energies for conduction decreased to 0.238 and 0.877 eV respectively, and the constant value of the thermoelectric power dropped to 1.0 mV deg. -1 . The theoretical implications of these results are discussed, and it is concluded that the existing semi-conductor models provide no satisfactory explanation of a temperature-independent thermoelectric power in a region where the number of current carriers is strongly dependent on temperature.

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