Effect of substrate to filament distance on formation and photoluminescence properties of indium catalyzed silicon nanowires using hot-wire chemical vapor deposition

• Published in: Thin solid films 2013-02, Vol.529, p.153-158
• Main Authors: Chong, Su Kong, Goh, Boon Tong, Dee, Chang Fu, Rahman, Saadah Abdul
• Format: Article
• Language: English
• Subjects: Catalysis; Catalysts: preparations and properties; Chemistry; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Filaments; General and physical chemistry; Hot-wire chemical vapor deposition; Indium; Materials science; Nanocrystals; Nanoscale materials and structures: fabrication and characterization; Nanostructure; Nanowires; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Other topics in nanoscale materials and structures; Photoluminescence; Physics; Quantum wires; Silicon; Silicon nanowires; Silicon substrates; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; Walls
• ISSN: 0040-6090; 1879-2731
• DOI: 10.1016/j.tsf.2012.07.098

Si nanowires have been synthesized by hot-wire chemical vapor deposition technique, with Indium nanocones employed as catalysts with different substrate to filament distances ranging from 6 to 3cm. Reducing the substrate to filament distance resulted in the retention of more atomic H radicals on the growth sites. The atomic H radicals acted to induce the catalytic growth and enhance the crystallinity of the Si nanowires. The Si nanowires showed tapering structures due to the radial growth of columnar Si nanocrystallites on the middle and base walls of the nanowires. The oxide-related defects on the outer layer of the Indium nanocones and Si nanowires, as well as the Si nanocrystallites on walls of the Si nanowires, contributed to the visible orange and red photoluminescence. ► Reduction of substrate to filament distance retained more H atoms on the growth sites. ► H atoms played a main role on inducing the catalytic growth of Si nanowires from In. ► Crystallinity of Si nanowires was enhanced due to the increase of H etching effect. ► Photoluminescence (PL) at 620nm related to oxide defects in In and Si structures. ► Si nanocrystalline columns on walls of the nanowires contributed the PL at 700nm.