Accession Number : ADA337751

Title :   The Spatial Coherence of Electron Wavefunctions and the Transition from Miniband to Stark-Ladder Electric Field Regimes in InGaAs/InAlAs-on-InP Superlattices

Descriptive Note : Progress rept. Jun 94-Sep 97

Corporate Author : ARMY RESEARCH LAB ADELPHI MD

Personal Author(s) : Bradshaw, John L. ; Leavitt, Richard P.

PDF Url : ADA337751

Report Date : FEB 1998

Pagination or Media Count : 24

Abstract : Five In0.53Ga0.47As/In0.52Al0.48As-on-InP superlattices of various well-to-barrier ratios and miniband widths have been studied by low-temperature photoluminescence, photocurrent, and differential photocurrent spectroscopies. These techniques provide a means of measuring the spatial coherence length of electron wavefunctions in the superlattices. We find that the onset of Wannier-Stark localization occurs when the well-to-well potential drop within the superlattice is between 1.1 and 1.43 times the low-temperature photoluminescence line width for all samples studied. Furthermore, the photoluminescence line width is accurately describable in terms of a simple model for alloy broadening. These findings confirm an intuitive picture for the transition between the miniband and Wannier-Stark electric field regimes in In0.53Ga0.48As/In0.52Al0.48As-on-InP superlattices.

Descriptors :   *SUPERLATTICES, *COHERENCE, SPATIAL DISTRIBUTION, GALLIUM ARSENIDES, PHOTOLUMINESCENCE, ALUMINUM ARSENIDES, WAVE FUNCTIONS, INDIUM PHOSPHIDES, BANDWIDTH, STARK EFFECT, PHOTOELECTRICITY.

Subject Categories : Electrooptical and Optoelectronic Devices
      Atomic and Molecular Physics and Spectroscopy
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE