Observation of the stochastic exciton dynamics in CuCl quantum dots

Dynamics of excitons and excitonic molecules in CuCl quantum dots are investigated by means of both time-resolved luminescence and transient absorption with use of sub-picosecond laser pulses. To explain the experimental results, a stochastic treatment by means of the Monte Carlo simulation and a rate-equation treatment are made, The former nicely explains the experimental results, while the latter does not. It is found that the exciton dynamics in CuCl quantum dots are characterized by its stochastic nature due to discreteness of the exciton number in a quantum dot.