We calculate the optical properties of nitride-based quantum dots by taking into account quantum confinement as well as electron–hole interaction. We analyze model structures simulating dots in layers with different alloy compositions. We discuss the trends with the dot size and show that quantum confined excitations exist for a broad range of sizes down to the smallest observed dots. Our results allow us to identify the strong role of Coulomb correlations in the optical spectra and to predict a strong influence of photoexcitation power on selection rules in polarized samples. The signature of quantum confinement can be utilized for a critical interpretation of measured optical spectra.
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1999
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