A Detailed Investigation of the Growth Conditions of Gallium Nitride Nanorods by Hydride Vapor Phase Epitaxy

摘要

We studied GaN nanorods grown by hydride vapour phase epitaxy processes to identify optimal growth conditions that yield nanorods appropriate for use in nanodevices. The growth temperature was varied over the range 625-670℃, and the morphology of the samples changed with increasing growth temperature. GaN nanorods formed at growth temperatures of 645 ℃ on a Si(111) substrate. At a fixed growth temperature of 645 ℃, the HCI;NH_3 gas flow ratio was adjusted from 1 : 37 to 1 : 41. GaN nanorods with a small diameter of 26 nm formed at a HCI:NH_3 ratio of 1 : 38. Individual GaN nanorods clearly grew along the axial direction, perpendicular to the substrate. Cathodoluminescence measurements at room temperature revealed a red shift as the acceleration energy was increased to 15keV, possibly associated with the internal electric field.