Field-Effect Spectroscopy of Interface States
Abstract
During the past year our research has been concerned principally with the synthesis by MBE of InxAl(1-x)As/InP 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 and/or 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 IN(x)Al(1-x)As layers with silicon during their MBE growth their Schottky barrier height, using C-V and internal photoemission measurements.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1988
- Accession Number
- ADA212998
Entities
People
- H. H. Wieder
Organizations
- University of California, San Diego