Title :
Photoluminescence excitation spectroscopy of the dense exciton gas involved in the lasing transition in ZnSe epitaxial layers
Author :
Kawakami, Y. ; Simpson, J. ; Prior, K.A. ; Cavenett, B.C.
Author_Institution :
Dept. of Phys., Heriot-Watt Univ., Edinburgh, UK
fDate :
4/1/1994 12:00:00 AM
Abstract :
The lasing transition in ZnSe epitaxial layers has been investigated at 77 K. The lowest lasing threshold (I/sub th/) was achieved when the layers were resonantly excited at the photon energy of the exciton level. It was found that the exciton level at the excitation intensity just above the I/sub th/ was red-shifted by about 16 meV compared with the free exciton line (2.792 eV) under weak excitation condition. The energy difference between the exciton line and the lasing peak was about 19 meV at I=I/sub th/ and increased with increasing excitation intensity up to I=8/spl times/I/sub th/. This suggests that the stimulated emission occurs due to the inelastic exciton-exciton scattering process at this temperature.<>
Keywords :
II-VI semiconductors; excitons; laser transitions; luminescence of inorganic solids; photoluminescence; semiconductor lasers; stimulated emission; zinc compounds; 19 meV; 2.792 eV; 77 K; ZnSe; ZnSe epitaxial layers; dense exciton gas; energy difference; excitation intensity; inelastic exciton-exciton scattering; lasing peak; lasing transition; lowest lasing threshold; photoluminescence excitation spectroscopy; photon energy; red-shift; resonantly excited; stimulated emission; weak excitation condition; Electromagnetic scattering; Epitaxial layers; Excitons; Particle scattering; Photoluminescence; Resonance; Spectroscopy; Stimulated emission; Temperature; Zinc compounds;
Journal_Title :
Photonics Technology Letters, IEEE
