GaN nanowires (NWs) were grown selectively on Si(111) substrate without catalyst by plasma-assisted molecular-beam epitaxy under N-rich conditions. The selective growth was obtained using regular arrays of holes patterned in a silicon oxide layer on top of a thin AlN buffer. The optical properties of the selectively grown GaN NWs have been studied using cathodoluminescence (CL) spectroscopy. Both, CL spectra measured on NW ensembles and spatially resolved monochromatic images were investigated. From a comparison of morphology and CL studies it emerges that NW coalescence is responsible for the appearance of the defect related emission.
International Society for Optics and Photonics
2 Mar 2011
Volume: 7939 Pages: 793903
Gallium Nitride Materials and Devices VI