Quantum-confinement effect on recombination dynamics and carrier localization in cubic InN and In xGa 1 − xN quantum boxes

Abstract

In this study, the quantum confinement effect on recombination dynamics and carrier localization in cubic InN ( c-InN) and cubic In x Ga 1 − x N ( c-In x Ga 1 − x N) low dimensional structures are theoretically examined. The small InN and In-rich In x Ga 1 − x N low dimensional structures show a strong quantum confinement effect, which results in ground states away from the band edge and discrete eigen-states. Depending on composition, temperature, and size of the InN and In x Ga 1 − x N low dimensional structures, quantum confinement effect can affect the exciton dimensions (D). In InN quantum cubes, the strong quantum confinement effect leads to temperature-dependent radiative lifetimes showing a large size variation. The nearly-temperature-independent and shorter radiative lifetimes in small InN and In-rich In x Ga 1 − x N low dimensional structures suggest that the strong quantum confinement leads to 0 D carrier confinement, stronger carrier localization, and high recombination efficiency. Reported radiative lifetimes were found to match very well with our simulation results of In-rich quantum cubes, which indicates that spontaneous emissions come from the radiative recombination of localized excitons in In-rich In x Ga 1 − x N clusters. The simulation results could provide important information for the designs and interpretations of c-InN and c-In x Ga 1 − x N devices.