Accession Number:

ADA125858

Title:

Experimental Studies of Lateral Electron Transport in Gallium Arsenide-Aluminum Gallium Arsenide Heterostructures.

Descriptive Note:

Doctoral thesis,

Corporate Author:

ILLINOIS UNIV AT URBANA COORDINATED SCIENCE LAB

Personal Author(s):

Report Date:

1982-12-01

Pagination or Media Count:

225.0

Abstract:

The electron-transport characteristics of modulation-doped GaAs-A1xGa1-xAs heterostructures have been measured over a wide range of temperatures using a diverse set of device structures. Short voltage pulses were used to apply a broad range of lateral parallel to the interface electric fields and the resulting current-field characteristics were determined using a sampling oscilloscope and x-y recorder. It was observed that the high electron mobility in these structures initially increased as the electric field was increased from zero. The low-field mobility reached a maximum at fields below 500 Vcm and then dropped quickly at low temperatures for increasingly higher electric fields. At higher temperatures 200 K to 300 K there was comparatively little change in the mobility for fields up to 2 kVcm. For higher fields above 2 kVcm it was found that the electrons could gain enough energy to be thermionically emitted over the conduction-band discontinuity from the high-mobility GaAs to the low-mobility A1GaAs. This real-space transfer RST of electrons resulted in current saturation or various degrees of negative differential resistance NDR in the samples being studied. It was demonstrated that the new real-space transfer mechanism could be used in the creation of fast electron switching and storage devices and also high-frequency oscillators.

Subject Categories:

  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE