Annealing Effects on the Thermoelectric Power and a Model for Low‐Field Conduction in Amorphous Germanium

Abstract

New measurements of the temperature dependence of conductivity u and thermopower Q in a-Ge a t different annealing stages are reported and a previous model for the low-field conduction is developed in order to account for experimental data. The model explains the TI14 law of the conductivity, CT = uo exp (-M T-1/4), gives concrete expressions for uo and M and accounts for the small negative values of Q in the TI14 region. An explanation for the annealing effects is sketched. Neue Messungen der Temperaturabhangigkeit der Leitfihigkeit u und der Thermokraft Q von a-Ge in verschiedenen Stadien der Temperung werden mitgeteilt. Ein fruheres Modell, das die Leitung bei niedrigen Feldern erklaren sollte, wird hier fur die Erklarung der MeDergebnisse weiterentwickelt. Aus dem Modell ergeben sich das T1/4 Gesetz fur die Leitfiihigkeit, u = uo exp (-M !P1I4), konkrete Ausdrucke fur uo und M und eine Erklarung der kleinen negativen &-Werte im TI14 Gebiet. Eine Erkliirung der Temperungseffekte wird skizziert.

Metal—Insulator Transition in Boron Carbide

“…This is also confirmed by the activation energy showing the behaviour E , -T3I4 (Fig. 5 ) , which is to be expected under these conditions [27]. Again the accordingly analyzed measurements of Geist et al [26] confirm this behaviour down to 25 K (Fig.…”

Hopping conductivity in ordered and disordered solids (II)

“…also [334, 336a, 349al). In this connection it should be referred to paper [320] , where an alternative model yielding a T-lI4 dependence is presented. Further, it should be noted, that a T-lI4-like dependence may also result from the polaron effect [94] (cf.…”

Nonequilibrium thermodynamic model of thermoelectricity and thermodiffusion in semiconductors

“…The Seebeck coefficients obtained in ref. 23, for example, are mostly from doped material with carrier concentrations above 10 17 cm À3 , despite the reference to intrinsic materials in the title. In ref.…”