Stochastic treatment of the dynamics of excitons and excitonic molecules in CuCl nanocrystals

Dynamics of excitons and excitonic molecules in CuCl nanocrystals were investigated by means of both picosecond time-resolved luminescence and femtosecond transient absorption. Stochastic as well as rate-equation treatments are made to explain the temporal changes of both luminescence and absorption. In the stochastic treatment, a Monte Carlo simulation is made for 10⁵ nanocrystals with the initial condition that the exciton number distribution follows the Poisson distribution. The stochastic treatment satisfactorily explains all the experimental results, while the rate-equation treatment does not. Success of the stochastic treatment shows the unique property of the dynamics of excitons and excitonic molecules in quantum dots arising from discreteness of the exciton number. {} 1996 The American Physical Society.