Synthesis and Raman optical properties of single-crystalline Bi nanowires

• Published in: Physica. E, Low-dimensional systems & nanostructures Vol. 44; no. 7-8; pp. 1142 - 1145
• Main Authors: Wang, Wenzhong, Liu, Meijing, Yang, Zhixiong, Mai, Weijie, Gong, Juntai
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-04-2012; Elsevier
• Subjects: Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Exact sciences and technology; Growth from solutions; Materials science; Methods of crystal growth; physics of crystal growth; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Optical properties of low-dimensional, mesoscopic, and nanoscale materials and structures; Physics; Quantum wires; Radiation effects; Raman spectra; Confinement; Red shift; Core shell structure; Phonons; Solvothermal synthesis; XRD; SAED; Laser irradiation; Raman spectroscopy; Spectral line shift; Monocrystals; Transmission electron microscopy; Optical properties; Crystal growth from solutions; Nanowires; Nanostructured materials
• ISSN: 1386-9477; 1873-1759
• DOI: 10.1016/j.physe.2012.01.001

Bi nanowires with diameters of 20–200nm, and length of up to more than 80μm were synthesized by a simple solvothermal method. The as-prepared Bi nanowires were characterized by XRD, TEM, SAED and HRTEM. The laser power dependent Raman optical properties of the Bi nanowires were investigated for the first time. The result indicated that two first-order Raman peaks of the as-prepared nanowires are red-shifted 6cm−1 compared with those of bulk Bi crystals after irradiation by laser with above 50% laser power. HRTEM investigations indicated that a Bi/oxide core/shell nanostructure was formed when the nanowires were irradiated by laser with above 50% laser power. A rational explanation for the red-shift of Raman peaks were discussed in detail according to phonon confinement model of an infinite crystal based on HRTEM results.
Two first-order Raman peaks of Bi nanowires are red-shifted 6cm−1 compared with bulk Bi crystals after irradiation by laser with above 50% laser power. [Display omitted]
► Single-crystalline Bi nanowires were achieved by a simple solvothermal method. ► Optical properties of the nanowires were investigated by Raman spectroscopy. ► Effect of laser power on optical properties of Bi nanowires was investigated. ► First-order Raman peaks of nanowires are red-shifted under above 50% laser power. ► Phonon confinement model has been used to explain the red-shift of Raman peaks.