Fabrication and Characterization of New Quantum Structures for Blue Lasers.
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.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1997
- Accession Number
- ADA322871
Entities
People
- N. Samarth
Organizations
- Pennsylvania State University