Multiple time scale blinking in InAs quantum dot single-photon sources

TL;DR

This study investigates blinking phenomena in InAs quantum dot single-photon sources over a wide range of timescales using photon correlation measurements, revealing complex multi-scale blinking behavior.

Contribution

It introduces a multi-level rate equation model to analyze blinking, providing insights into dark states and quantum yields in quantum dot emitters.

Findings

Blinking occurs over tens of nanoseconds to tens of milliseconds.

Quantum yields are significantly less than 1 due to dark states.

Multi-level modeling reveals complex non-radiative processes.

Abstract

We use photon correlation measurements to study blinking in single, epitaxially-grown self-assembled InAs quantum dots situated in circular Bragg grating and microdisk cavities. The normalized second-order correlation function g(2)(\tau) is studied across eleven orders of magnitude in time, and shows signatures of blinking over timescales ranging from tens of nanoseconds to tens of milliseconds. The g(2)(\tau) data is fit to a multi-level system rate equation model that includes multiple non-radiating (dark) states, from which radiative quantum yields significantly less than 1 are obtained. This behavior is observed even in situations for which a direct histogramming analysis of the emission time-trace data produces inconclusive results.