Influence of the atom source operating parameters on the structural and optical properties of In xGa 1 - xN nanowires grown by plasma-assisted molecular beam epitaxy

The influence of the atom source operating parameters on the structural and optical properties of In _xGa _{1 - x}N/GaN nanowires (NWs) grown by plasma-assisted molecular beam epitaxy is investigated. Electron microscopy and photoluminescence spectroscopy reveal a change of the NW tip morphology and an enhancement of the local indium incorporation with increasing nitrogen flux. Tuning the density ratio of atomic-to-excited molecular nitrogen to lower values minimizes the point defect density, which results in a decrease of the non-radiative recombination rate as demonstrated by a combination of continuous wave and time-resolved photoluminescence spectroscopy.