Laser-Assisted Catalytic Growth of Single Crystal GaN Nanowires

Xiangfeng Duan and Charles M. Lieber*Department of Chemistry and Chemical BiologyHarVard UniVersity, Cambridge, Massachusetts 02138ReceiVed October 18, 1999Herein we report the bulk synthesis of single crystalline GaNnanowires. Laser ablation of a composite target of GaN and acatalytic metal generates liquid nanoclusters that serve as reactivesites confining and directing the growth of crystalline nanowires.Field emission scanning electron microscopy (FE-SEM) showsthat the product primarily consists of wire-like structures. PowderX-ray diffraction (PXRD) analyses of a bulk nanowire samplecan be indexed to the GaN wurtzite structure, and indicate >95%phase purity. Transmission electron microscopy (TEM), conver-gent beam electron diffraction (CBED), and energy-dispersiveX-ray fluorescence (EDX) analyses of individual nanowires showthat they are GaN single crystals with a [100] growth direction.Nanostructured GaN materials have attracted extensive interestover the past decade due to their significant potential foroptoelectronics.