High Purity GaAs Nanowires Free of Planar Defects: Growth and Characterization

• Published in: Advanced functional materials 2008-12, Vol.18 (23), p.3794-3800
• Main Authors: Joyce, Hannah J., Gao, Qiang, Tan, H. Hoe, Jagadish, Chennupati, Kim, Yong, Fickenscher, Melodie A., Perera, Saranga, Hoang, Thang Ba, Smith, Leigh M., Jackson, Howard E., Yarrison-Rice, Jan M., Zhang, Xin, Zou, Jin
• Format: Article
• Language: English
• Subjects: defects; gallium arsenide; inorganic nanowires; metal-organic CVD; photoluminescence
• ISSN: 1616-301X; 1616-3028
• DOI: 10.1002/adfm.200800625

We investigate how to tailor the structural, crystallographic and optical properties of GaAs nanowires. Nanowires were grown by Au nanoparticle‐catalyzed metalorganic chemical vapor deposition. A high arsine flow rate, that is, a high ratio of group V to group III precursors, imparts significant advantages. It dramatically reduces planar crystallographic defects and reduces intrinsic carbon dopant incorporation. Increasing V/III ratio further, however, instigates nanowire kinking and increases nanowire tapering. By choosing an intermediate V/III ratio we achieve uniform, vertically aligned GaAs nanowires, free of planar crystallographic defects, with excellent optical properties and high purity. These findings will greatly assist the development of future GaAs nanowire‐based electronic and optoelectronic devices, and are expected to be more broadly relevant to the rational synthesis of other III–V nanowires. Eliminating structural defects, crystallographic defects and intrinsic dopants in nanowire “nano‐components” is critical for development of nanowire‐based devices. High purity, uniformly aligned epitaxial GaAs nanowires free of planar crystallographic defects and with excellent optical properties are demonstrated. The figure shows SEM and TEM images and the photoluminescence spectrum of these excellent nanowires.