Hole subband mixing and polarization of luminescence from quantum dashes: a simple model - Condensed Matter > Mesoscale and Nanoscale PhysicsReport as inadecuate




Hole subband mixing and polarization of luminescence from quantum dashes: a simple model - Condensed Matter > Mesoscale and Nanoscale Physics - Download this document for free, or read online. Document in PDF available to download.

Abstract: In this paper, we address the problem of luminescence polarization in thecase of nanostructures characterized by an in-plane shape asymmetry. We developa simple semi-qualitative model revealing the mechanism that accounts for theselective polarization properties of such structures. It shows that they arenot a straightforward consequence of the geometry but are related to it viavalence subband mixing. Our model allows us to predict the degree ofpolarization DOP dependence on the in-plane dimensions of investigatedstructures assuming a predominantly heavy hole character of the valence bandstates, simplifying the shape of confining potential and neglecting theinfluence of the out-of plane dimension. The energy dependence modeling revealsthe importance of different excited states in subsequent spectral rangesleading to non-monotonic character of the DOP. The modeling results show goodagreement with the experimental data for an ensemble of InAs-InP quantum dashesfor a set of realistc parameters with the heavy-light hole states separationbeing the only adjustable one. All characteristic features are reproduced inthe framework of the proposed model and their origin can be well explained andunderstood. We also make some further predictions about the influence of boththe internal characteristics of the nanostructures e.g. height and theexternal conditions excitation power, temperature on the overall DOP.



Author: Piotr Kaczmarkiewicz, Anna Musiał, Grzegorz Sęk, Paweł Podemski, Paweł Machnikowski, Jan Misiewicz

Source: https://arxiv.org/







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