A simple lattice model describing the recombination dynamics in visible-light-emitting porous silicon is presented. In the model, each occupied lattice site represents a Si crystal of nanometre size. The disordered structure of porous silicon is modelled by modified random percolation networks in two and three dimensions. Both correlated (excitons) and uncorrelated electron-hole pairs have been studied. Radiative and non-radiative processes as well as hopping between nearest-neighbour occupied sites are taken into account. By means of extensive Monte Carlo simulations, we show that the recombination dynamics in porous silicon is due to a dispersive diffusion of excitons in a disordered arrangement of interconnected Si quantum dots. The simulated luminescence decay for the excitons shows a stretched exponential lineshape while for uncorrelated electron-hole pairs a power-law decay is suggested. Our results successfully account for the recombination dynamics recently observed in experiments. The present model is a prototype for a larger class of models describing diffusion of particles in a complex disordered system.

Roman, H., Pavesi, L. (1996). Monte Carlo simulations of the recombination dynamics in porous silicon. JOURNAL OF PHYSICS. CONDENSED MATTER, 8(28), 5161-5187 [10.1088/0953-8984/8/28/003].

Monte Carlo simulations of the recombination dynamics in porous silicon

Roman H. E.;Pavesi L.
1996

Abstract

A simple lattice model describing the recombination dynamics in visible-light-emitting porous silicon is presented. In the model, each occupied lattice site represents a Si crystal of nanometre size. The disordered structure of porous silicon is modelled by modified random percolation networks in two and three dimensions. Both correlated (excitons) and uncorrelated electron-hole pairs have been studied. Radiative and non-radiative processes as well as hopping between nearest-neighbour occupied sites are taken into account. By means of extensive Monte Carlo simulations, we show that the recombination dynamics in porous silicon is due to a dispersive diffusion of excitons in a disordered arrangement of interconnected Si quantum dots. The simulated luminescence decay for the excitons shows a stretched exponential lineshape while for uncorrelated electron-hole pairs a power-law decay is suggested. Our results successfully account for the recombination dynamics recently observed in experiments. The present model is a prototype for a larger class of models describing diffusion of particles in a complex disordered system.
Articolo in rivista - Articolo scientifico
silicon nanoclusters, radiative recombination processes, Monte Carlo simulations
English
1996
8
28
5161
5187
none
Roman, H., Pavesi, L. (1996). Monte Carlo simulations of the recombination dynamics in porous silicon. JOURNAL OF PHYSICS. CONDENSED MATTER, 8(28), 5161-5187 [10.1088/0953-8984/8/28/003].
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/326710
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