P2.4.18 MBE growth of GaN nanowires on Si(111) substrates for gas sensor applications

Abstract

GaN nanowires (NWs) were grown on Si(111) substrates by plasma-assisted molecular beam epitaxy (PAMBE). The NWs nucleated spontaneously, no catalyst was used for their growth. SEM studies show that the NWs are homogenously distributed and well aligned with the c-axis being perpendicular to the substrate, while TEM analysis reveals their high crystalline quality. No GaN wetting layer between NWs was detected. Two types of NWs-based gas sensors were prepared. Our preliminary tests in NO2, NH3 and hydrogen atmospheres at temperatures up to 80 o C show that structures of GaN NWs on Si are promising building blocks for simple and highly sensitive gas sensor devices.