Complex diffusion-based kinetics of photoluminescence in semiconductor nanoplatelets

Abstract

We present a diffusion-based simulation and theoretical models for explanation of photoluminescence (PL) emission intensity in semiconductor nanoplatelets. It is shown that the shape of PL intensity curves can be reproduced by the interplay of recombination, diffusion and trapping of excitons. The emission intensity at short times is purely exponential and is defined by recombination. At long times it is governed by the release of excitons from surface traps and is characterized by a power-law tail. We show that the crossover from one limit to another is controlled by diffusion properties. This intermediate region exhibits a rich behaviour depending on the value of diffusivity. Proposed approach reproduces all the features of experimental curves measured for different nanoplatelet systems.

arXiv comment11 pages, 10 figures

References in corpus (7)

• Low-threshold stimulated emission using colloidal quantum wells
• Exciton diffusion and halo effects in monolayer semiconductors
• Exciton diffusion in two-dimensional metal-halide perovskites
• Tight-binding calculations of image charge effects in colloidal nanoscale platelets of CdSe
• Exciton diffusion in monolayer semiconductors with suppressed disorder
• Addressing the exciton fine structure in colloidal nanocrystals: the case of CdSe nanoplatelets
• Phonon wind and drag of excitons in monolayer semiconductors

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• Negative diffusion of excitons in quasi-two-dimensional systems
• Photoluminescence decay of mobile carriers influenced by imperfect quenching at particle surfaces with subdiffusive spread
• Viscous hydrodynamics of excitons in van der Waals heterostructures
• Non-normalizable quasi-equilibrium states under fractional dynamics
• Evaluating Gaussianity of heterogeneous fractional Brownian motion
• Effect of spin-dependent tunneling and intervalley scattering in magnetic-semiconductor van der Waals heterostructures on exciton and trion polarization