Macro- and micro-strain in GaN nanowires on Si(111)

Abstract

We analyze the strain state of GaN nanowire ensembles by x-ray diffraction. The nanowiresare grown by molecular beam epitaxy on a Si(111) substrate in a self-organizedmanner. On a macroscopic scale, the nanowires are found to be free of strain.However, coalescence of the nanowires results in micro-strain with a magnitude from ± (0.015)% to ± (0.03)%. This micro-strain contributes to the linewidth observed in low-temperaturephotoluminescence spectra.