ISSN:
1057-9257
Schlagwort(e):
High-density luminescence
;
Non-linear transmission
;
ZnTe
;
Metal-organic vapour phase epitaxy
;
Inelastic exciton scattering
;
Electron-hole plasma
;
Pump-and-probe method
;
Exciton screening
;
Band gap renormalization
;
Chemistry
;
Polymer and Materials Science
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Elektrotechnik, Elektronik, Nachrichtentechnik
,
Physik
Notizen:
We investigated the high-density luminescence and non-linear transmission of ZnTe layers grown by metal-organic vapour phase epitaxy (MOVPE). For the high-density luminescence we compared ZnTe layers on (001) GaAs substrate with free-standing ZnTe layers of equal thickness. At high excitation intensities a strong luminescence P band appears a few meV below the free exciton energy which is assigned to resonant exciton-scattering processes. A second strong luminescence N band occurs only in free-standing layers. It shows a remarkable red shift with increasing intensity and becomes the dominant emission for an excitation intensity Iexc 〉 1.5 MW cm-2. This lower-energy band was interpreted as electron-hole plasma recombination.The optical non-linearity of thin ZnTe layers in the excitonic region was investigated by pump-and-probe experiments at 2 K and room temperature (RT). For these experiments we used two different pump energies, one above (at 2 K and RT) and one below (at 2 K) the band gap energy. In all cases a red shift and a large non-linear decrease in the excitonic absorption with increasing pump intensity was observed. The experimental results can be explained by many-body effects of exciton screening.
Zusätzliches Material:
6 Ill.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1002/amo.860030106
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