Low mobility materials and Debye dielectric loss due to electrons

Fröhlich, H.; Machlup, Stefan; Mitra, Tapas

doi:10.1007/bf02422333

Cited by 16 publications

(3 citation statements)

References 7 publications

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“…This occurs, for example, in the case of electrons interacting with the polarization, i.e. with polar phonons of frequency wp (see Frohlich 1937, Frohlich andMott 1939), in an ionic crystal when the inertial polarization, due mainly to ion displacements, is sufficiently great. Landau (1933) has pointed out that a sufficiently strong coupling leads to a polarization potential well e+,(r) and to the so-called selftrapping (autolocalization) of the electron (see also Blochintzev 1936, Frenkel 1936, Gurney and Mott 1937.…”

Section: The Polaron Problem In Solid State Theorymentioning

confidence: 99%

Electrons in low-mobility and disordered semiconductors: theory of transport and related optical phenomena

Klinger

1968

Rep. Prog. Phys.

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Section: The Polaron Problem In Solid State Theorymentioning

confidence: 99%

Electrons in low-mobility and disordered semiconductors: theory of transport and related optical phenomena

Klinger

1968

Rep. Prog. Phys.

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“…According to other investigators, the photodielectric effect is due to trapping : electrons are trapped at some sites in the crystal and form polarizable complexes giving rise to a dipolar Debye absorption [ 2 ] . These complexes having a high polarizability [3], the change in the dielectric constant can be very large even though a small amount of electrons is trapped. The change shows a saturation when the trap population has reached its equilibrium value.…”

Section: Introductionmentioning

confidence: 99%

Properties of traps determined from the optical quenching of luminescence and dielectric losses in ZnS:Cu

Chudàaček

Scarmozzino

1970

Phys. Stat. Sol. (a)

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Measurements of dielectric losses in ZnS: Cu single crystals illuminated by uv light have been made by means of a high sensitive microwave apparatus. The quenching of dielectric losses by visible light in ZnS: Cu single crystals as a function of wavelength (optical quenching spectrum) has been measured at room temperature in the range 0.4 to 0.8 μm. Moreover, a series of simultaneous measurements of luminescence and dielectric losses using as a source of quenching light an mW He‐Ne laser are reported in order to test some proposed models for the mechanism of optical quenching. A satisfactory account for the present results is obtained in terms of non‐radiative recombinations between trapped electrons and free holes in the valence band. The kinetic of these recombinations is not the same if the quenching light is applied after or in addition to the uv excitation. The results show also that the dielectric behaviour of shallow and deep traps is different.

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“…An explanation of this relaxational behaviour can be given in terms of a tunneling process by which the electron, trapped near a defect, may pass through potential barriers between those equivalent sites at which the electron may be localized more specifically. Thermal excitation may then bring the electron also from the ground state to (in the case of smoky quartz at least 2) intermediate states in which phonon-assisted transitions through the potential barrier may occur [4,6,7]. The energy levels of these excited states obviously are 8.5 and 85 meV above ground level.…”

mentioning

confidence: 99%

Dielectric relaxation processes in smoky quartz crystals at very low temperatures

Vos

Volger

1967

Physics Letters A

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CRYSTALSThe relaxation time governing the dielectric loss of smoky quartz crystals appears to level off as a function of temperature below 12OK, approaching a value of about 1 msec. The relaxational behaviour of the colour centres is discussed in terms of tunnelling processes.Under favorite conditions, lattice imperfections at which electrons are trapped (e.g. colour centres) may exhibit a Debye type dielectric response [1,2]. A very clear case is found with smoky quartz crystals [3], which has recently been reinvestigated [4] by the present authors, especially between 20 ° and 160OK. In this letter we wish to report our measurements on the temperature dependence of the dielectric relaxation time extended downwards to 4°K, using the same specimen, with E //c-axis.According to the well-known Debye relaxation theory the dielectric loss factor tg 8 as a function of frequency and temperature should follow the expression 4~ {E + 2~ 2 Np 2 wTin which e is the dielectric constant of the matrix, N and p the concentration and dipole strength of the centres, and T the absolute temperature.

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Low mobility materials and Debye dielectric loss due to electrons

Cited by 16 publications

References 7 publications

Electrons in low-mobility and disordered semiconductors: theory of transport and related optical phenomena

Electrons in low-mobility and disordered semiconductors: theory of transport and related optical phenomena

Properties of traps determined from the optical quenching of luminescence and dielectric losses in ZnS:Cu

Dielectric relaxation processes in smoky quartz crystals at very low temperatures

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