Accession Number : ADA322871

Title :   Fabrication and Characterization of New Quantum Structures for Blue Lasers.

Descriptive Note : Final technical rept.,

Corporate Author : PENNSYLVANIA STATE UNIV UNIVERSITY PARK

Personal Author(s) : Samarth, N.

PDF Url : ADA322871

Report Date : 01 FEB 1997

Pagination or Media Count : 11

Abstract : We have investigated the growth of (Zn,Mn)(S,Se) epitaxial layers of high structural quality on (100) GaAs substrates. Double crystal x-ray diffraction (DCXRD) measurements indicate that quaternary epilayers nearly lattice-matched with GaAs are characterized by DCXRD curves with a full width at half maximum in the range 30-60 arc seconds. This indicates the successful fabrication of epitaxial layers with excellent structural integrity. Photoluminescence (PL) spectroscopy is employed to map the variation of the energy gap of the quaternary alloys over a wide range of alloy compositions. It is found that exchange related effects on band gap bowing lead to a smaller than anticipated increase in the energy gap as a function of the Mn composition. Finally, temperature dependent PL is used to examine the viability of (Zn,Mn)(S,Se) alloys as confining layers for ZnSe and (Zn,Cd)Se quantum wells. Efficient exciton confinement is demonstrated through the observation of robust PL from such quantum wells up to high temperatures. However, the renormalization of the quarternary band gap by spin fluctuations leads to a rapid decrease in the energy gap of the (Zn,Mn)(S,Se) alloys with increase in temperature, leading to limitations in quantum confinement, particularly in the conduction band.

Descriptors :   *QUANTUM WELLS, *GALLIUM ARSENIDES, *EPITAXIAL GROWTH, PHOTOLUMINESCENCE, X RAY DIFFRACTION, ENERGY GAPS, SUBSTRATES, CONDUCTION BANDS, SULFUR, QUATERNARY COMPOUNDS, EXCITONS, MAGNESIUM ALLOYS, LASER MATERIALS, ZINC SELENIDES.

Subject Categories : Quantum Theory and Relativity
      Lasers and Masers

Distribution Statement : APPROVED FOR PUBLIC RELEASE