Optics of Zero Dimensional Semiconductor Systems |
A.I. Ekimov and Al.L. Efros S.I. Vavilov State Optical Institute, 199164 Leningrad, USSR |
Received: August 8, 1990 |
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The optical spectra of semiconductor microcrystals grown in transparent matrix of oxide glass are investigated. The size of microcrystals was varied in a controlled manner from a few tens to a few hundreds of angstroms. The microcrystal embedded in wide gap matrix represents three-dimensional potential well for electrons, holes and excitons. The optical properties of such zero-dimensional semiconductor structures are shown to be governed by the structure of energy spectra of confined electron-hole pairs. The phenomenon of the microcrystals ionization at interband optical excitation is observed. The Auger process in microcrystals containing two nonequilibrium electron-hole pairs is proposed to be responsible for this effect. The experimental dependencies of the ionization rate as a function of excitation intensity and the microcrystal size are in a good agreement with the theoretical predictions of the Auger recombiantion model. |
DOI: 10.12693/APhysPolA.79.5 PACS numbers: 78.90.+t |