Carrier trapping and luminescence polarization in quantum dashes

Abstract

We study experimentally and theoretically polarization-dependent luminescence from an ensemble of quantum-dot-like nanostructures with a very large in-plane shape anisotropy (quantum dashes). We show that the measured degree of linear polarization of the emitted light increases with the excitation power and changes with temperature in a non-trivial way, depending on the excitation conditions. Using an approximate model based on the k.p theory, we are able to relate this degree of polarization to the amount of light hole admixture in the exciton states which, in turn, depends on the symmetry of the envelope wave function. Agreement between the measured properties and theory is reached under assumption that the ground exciton state in a quantum dash is trapped in a confinement fluctuation within the structure and thus localized in a much smaller volume of much lower asymmetry than the entire nanostructure.

13 pages, 9 figures; considerably extended, additional discussion and new figures included

References in corpus (3)

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• Excitonic exchange effects on the radiative decay time of monoexcitons and biexcitons in quantum dots
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Cited by in corpus (11)

• Exciton lifetime and emission polarization dispersion in strongly in-plane asymmetric nanostructures
• Optical and electronic properties of low-density InAs/InP quantum dot-like structures devoted to single-photon emitters at telecom wavelengths
• Polarization anisotropy of the emission from type-II quantum dots
• Hyperfine interaction for holes in quantum dots: k.p model
• From Quantum Dots to Quantum Dashes: Excitonic Spectra of Highly Elongated InAs/InP Nanostructures
• Excited states of neutral and charged excitons in single strongly asymmetric InP-based nanostructures emitting in the telecom C band
• Exciton spin relaxation in InAs/InGaAlAs/InP(001) quantum dashes emitting near 1.55 μm
• Electronic and optical properties in non-uniformly shaped QDashes
• Double quantum dot in a quantum dash: optical properties
• Quantum dots as optimized chiral emitters for photonic integrated circuits
• Carrier trapping in a quantum dash: optical signatures