title: Solution synthesis of germanium nanowires using a Ge2+ alkoxide precursor.
abstract: A simple solution synthesis of germanium (Ge0) nanowires under mild conditions (<400 degrees C and 1 atm) was demonstrated using germanium 2,6-dibutylphenoxide, Ge(DBP)2 (1), as the precursor where DBP = 2,6-OC6H3(C(CH3)3)2. Compound 1, synthesized from Ge(NR2)2 where R = SiMe3 and 2 equiv of DBP-H, was characterized as a mononuclear species by single-crystal X-ray diffraction. Dissolution of 1 in oleylamine, followed by rapid injection into a 1-octadecene solution heated to 300 degrees C under an atmosphere of Ar, led to the formation of Ge0 nanowires. The Ge0 nanowires were characterized by transmission electron microscopy (TEM), X-ray diffraction analysis, and Fourier transform infrared spectroscopy. These characterizations revealed that the nanowires are single crystalline in the cubic phase and coated with oleylamine surfactant. We also observed that the nanowire length (0.1-10 microm) increases with increasing temperature (285-315 degrees C) and time (5-60 min). Two growth mechanisms are proposed based on the TEM images intermittently taken during the growth process as a function of time: (1) self-seeding mechanism where one of two overlapping nanowires serves as a seed, while the other continues to grow as a wire; and (2) self-assembly mechanism where an aggregate of small rods (<50 nm in diameter) recrystallizes on the tip of a longer wire, extending its length.
authors.affiliation: Department of Chemical and Nuclear Engineering, University of New Mexico, 209 Farris Engineering Center, Albuquerque, New Mexico 87131, USA. meister@unm.edu
authors.forename: Henry
authors.initials: H
authors.lastname: Gerung
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Boyle
authors.forename: Louis J
authors.initials: LJ
authors.lastname: Tribby
authors.forename: Scott D
authors.initials: SD
authors.lastname: Bunge
authors.forename: C Jeffrey
authors.initials: CJ
authors.lastname: Brinker
authors.forename: Sang M
authors.initials: SM
authors.lastname: Han
mesh_terms: D005857:Germanium / Q000737:chemistry*; D053770:Nanowires / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry; D010087:Oxides / Q000737:chemistry; D010636:Phenols / Q000737:chemistry; D012996:Solutions; D017550:Spectroscopy, Fourier Transform Infrared; D014961:X-Ray Diffraction
chemical_list: D009942:Organometallic Compounds; D010087:Oxides; D010636:Phenols; D012996:Solutions; D005857:Germanium