Title :
Observation of higher subband emission from PbSe two-dimensional layers
Author :
Herrmann, Klaus H. ; Tomm, Jens W. ; Haertel, Sebastian ; Tacke, Maurus ; Bottner, Harald
fDate :
7/1/1995 12:00:00 AM
Abstract :
Energy relaxation of an optically excited two-dimensional electron-hole gas has been investigated in PbSe as an example for dimensional quantization in a semiconductor with nearly symmetric valence and conduction band extrema. As compared with bulk-like reference samples the interband emission exhibits broadening and splitting into up to 5 clearly resolved lines. A systematic variation of the spectra with excitation density was observed: With increasing pump intensity the width of the total spectrum and the number of subbands increase due to both carrier heating and band filling. The emission bands are attributed to transitions between conduction and valence subbands with equal quantum number. Above a threshold well pronounced for each subband transition, the emission becomes stimulated. That indicates a potential for laser applications
Keywords :
II-VI semiconductors; conduction bands; laser transitions; lead compounds; optical films; optical pumping; semiconductor lasers; stimulated emission; two-dimensional electron gas; valence bands; PbSe; PbSe two-dimensional layers; band filling; broadening; bulk-like reference samples; carrier heating; clearly resolved lines; conduction band extrema; dimensional quantization; emission bands; energy relaxation; equal quantum number; excitation density; higher subband emission; interband emission; laser applications; nearly symmetric valence band extrema; optically excited two-dimensional electron-hole gas; pump intensity; semiconductor lasers; splitting; stimulated; Diode lasers; Gallium arsenide; Laser transitions; Mercury (metals); Optical pumping; Physics; Plasma applications; Quantization; Quantum well lasers; Stimulated emission;
Journal_Title :
Quantum Electronics, IEEE Journal of
