Comparison of GaN Nanoneedle Structures Formed by Using the HVPE Method

We grew different morphologies of GaN nanostructures on AlN/Si(111) substrates by using hydride vapor phase epitaxy (HVPE). Among them, we focused on nanoneedles, nanoneedle flowers and nanoneedle chestnuts to determine their different growth mechanisms. The nanoneedle flowers were mainly caused by the roughness of the substrate. However, nanoneedle chestnuts were grown in air by the lift-off force of the N_2 carrier gas and then fell and grew larger. These nanoneedle structures were analyzed by field emission scanning electron microscopy, high-resolution transmission electron microscopy, energy dispersive X-ray spectroscopy, and cathodoluminescence. KCI Citation Count: 2