Blinking Mechanism of Colloidal Semiconductor Quantum Dots: Role of Fluctuating Double Layer Potential

摘要

Colloidal semiconductor quantum dots are observed to blink with off- and on-times, τ_(off), and τ_(on), respectively, that obey inverse power law distributions. In this paper, the role of the fluctuating double-layer potential in the blinking phenomenon is examined. As discussed, the existence of an energy barrier, E, that is a stochastic variable with an exponential distribution Pe(E) = (1/E_o)exp(-E/E_o) in terms of the height of the energy variable, results in a distribution in the thermal activation time t, P_τ(τ), is described by an inverse power law. As discussed, in such cases, an Arrhenius process is characterized by a thermal activation time, τ, where τ = τ_oexp(E/k_BT) and E represents the energy barrier, T is the temperature, k_B is Boltzmann's constant, and τ_o is a typical time. These principles are applied to the case of colloidal semiconductor quantum dots in electrolytic suspensions to analyze the role of the fluctuating double-layer potential in the blinking of colloidal semiconductor quantum dots.