Accession Number : AD0752100

Title :   Conduction Mechanisms for Electronic Devices.

Descriptive Note : Interim rept. 3 May-2 Oct 72,

Corporate Author : RCA LABS PRINCETON N J

Personal Author(s) : Redfield,David

Report Date : NOV 1972

Pagination or Media Count : 17

Abstract : Previously developed techniques of preparing controlled energy band tails in heavily doped, closely compensated GaAs are being exploited to exhibit the electronic transport properties in band tails. These properties closely resemble the corresponding properties of amorphous semiconductors but the control available in the present materials has added greatly to the capabilities necessary for understanding the unclear behavior in amorphous semiconductors. A systematic program of relating several different properties has been started to increase the value of the separate measurements (e.g., temperature and electric field dependence of the d.c. conductivity, a.c. conductivity, and photoconductivity). One of the specific results of primary interest was the highly detailed, accurate measurement of the temperature dependence of the d.c. conductivity which displayed the relation Log sigma approximately equal to T to the minus 1/2 power. Theory indicates that this suggests one-dimensional conduction in the band tails since normal, three-dimensional conduction should give log sigma approximately=T to the-1/4 ;ower. The other major result showed that the low-temperature conductivity has a nearly exponential dependence on electric field strength, extending down to approximately 2 V/cm. This very low-field sensitivity is unexpected and is the basis for increased understanding of the electronic behavior in band tails. (Author)

Descriptors :   (*SEMICONDUCTORS, *BAND THEORY OF SOLIDS), (*GALLIUM ARSENIDES, ELECTRICAL CONDUCTIVITY), PHOTOCONDUCTIVITY, THERMAL PROPERTIES, ELECTRIC FIELDS, CAPACITANCE

Subject Categories : Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE