We report on the carrier dynamics in InGaN/GaN dot-in-nanowire quantum dots, revealed by a systematic mapping between the optical properties and structural parameters of the quantum dots. Such a study is made possible by using quantum dots with precisely controlled locations and sizes. We show that the carrier dynamics is governed by two competing mechanisms: (1) Excitons are protected from surface recombination by a potential barrier formed due to strain relaxation at the sidewall surface. (2) Excitons can overcome the potential barrier by tunneling and thermal activation. This carrier dynamics model successfully explains the following surprising experimental findings on individual quantum dots. First, there exist strong statistical correlations among multiple optical properties of many individual quantum dots, despite variations of these properties resulting from inevitable structural variations among the quantum dots. Second, the antibunching property of the quantum dot emission exhibits an abnormal ladle-shaped dependence on the decay time and temperature. Our results can guide the way toward nitride-based high-temperature single-photon emitters and nanophotonic devices.

• Received 6 May 2014
• Revised 3 November 2014

DOI:https://doi.org/10.1103/PhysRevB.90.245311