Direction-Dependent Homoepitaxial Growth of GaN Nanowires


  • This work was supported by U.S. Air Force Research (AFOSR, F49620-00-1-0310, monitored by Dr. Gerald Witt), U.S. National Science Foundation (CTS 9 876 251), and the Kentucky Science & Engineering Foundation (KSEF-148-502-04-86). The authors acknowledge Dr. Xu at the University of Kentucky for help with HRTEM and Dr. Raul Miranda of the Basic Energy Sciences Division at the U.S. Department of Energy for helpful discussions. Supporting Information is available online from Wiley InterScience or from the author.


original image

GaN nanowires with vastly different morphologies depending upon the growth direction are produced by direct nitridation and vapor transport of Ga in disassociated ammonia. Nanowires grown homoepitaxially along the c-direction develop hexagonal-prism island morphologies (see Figure, left, and Cover), while wires grown along the a-direction form uniform, belt-shaped morphologies (Figure, right). A “ballistic” transport phenomenon for adatoms is proposed to explain the observed prismatic island morphologies.