Accession Number:

ADA212998

Title:

Field-Effect Spectroscopy of Interface States

Descriptive Note:

Final rept. 1 May 1985-31 Dec 1988

Corporate Author:

CALIFORNIA UNIV SAN DIEGO LA JOLLA DEPT OF ELECTRICAL AND COMPUTER ENGINEERING

Personal Author(s):

Report Date:

1988-12-31

Pagination or Media Count:

77.0

Abstract:

During the past year our research has been concerned principally with the synthesis by MBE of InxAl1-xAsInP heterojunctions in strained layer structures SLS. Some of the layers were grown with their lattice constants matched to that of their 100-oriented InP substrates. Others were chosen deliberately to be in compression or in tension and with appropriate combinations of their fractional indium concentration, x, and thickness, d, were intended to be strained pseudomorphically or strain-relaxed by the generation andor motion of misfit dislocations. Conventional as well as double crystal rocking curve X-ray diffraction of the 400-reflection plane was used to determine the composition-dependent lattice constant and PL spectroscopic measurements at temperatures near 4K and 300K were used to determine the fundamental bandgap of the various layers. The pseudomorphic strain-dependent shifts of the fundamental bandgaps were determined using a linear interpolation between the InAs and AlAs elastic stiffness coefficients, hydrostatic pressure coefficients and shear deformation potentials. These calculations were shown in good agreement with experimental measurements. The calculated composition- dependent critical thickness for the onset of plastic deformation and total relaxation of the strain determined from these measurements is in better agreement with the energy balance model than with the mechanical equilibrium model of Matthews and Blakeslee. By donor-doping our SI INxAl1-xAs layers with silicon during their MBE growth their Schottky barrier height, using C-V and internal photoemission measurements.

Subject Categories:

  • Solid State Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE