AVS 57th International Symposium & Exhibition
    Nanometer-scale Science and Technology Tuesday Sessions
       Session NS-TuP

Paper NS-TuP10
On the Photoluminescence of Zn2GeO4 Nanorods Synthesized by a Simple Solution Route

Tuesday, October 19, 2010, 6:00 pm, Room Southwest Exhibit Hall

Session: Nanometer-Scale Science and Technology Poster Session
Presenter: M.Y. Tsai, National Applied Research Laboratories, Taiwan, Republic of China
Authors: M.Y. Tsai, National Applied Research Laboratories, Taiwan, Republic of China
T.P. Perng, National Tsing Hua University, Taiwan, Republic of China
Correspondent: Click to Email
During the past decade, there has been increasing interest in ternary oxide nanomaterials due to their unique electronic, optical, and chemical properties. In the present study, Zn2GeO4 nanorods exhibiting intense white blue-green luminescence were synthesized using a reflux method. Stoichiometric GeO2 (1 mmole) and zinc acetate (2 mmole) were pre-dissolved in deionized water separately, and the solution mixture was subsequently refluxed at 160℃ with the aid of magnetic stirring. From scanning electron microscopic observation, the obtained product (denoted as sample A) was an aggregation of short nanorods. The diameter of nanorod ranges from 30 to 50 nm, and the length is approximately 300 nm. X-ray diffraction (XRD) analysis reveals that these nanorods exhibit a pure Zn2GeO4 phase of phenacite structure. If the concentration of reactants were increased by 5 times, the nanorods became longer and tended to aggregate to form bundles (denoted as sample B). Further, the full width at half maximum (FWHM) of XRD peaks measured from sample B was smaller than that of sample A, indicating a larger mean grain size. Since Zn2GeO4 is a self-activated phosphor, the photoluminescence (PL) of these two specimens was also measured. An intense white blue-green light emission was observed from sample A, and the broad PL band distributed from 400 nm to 600 nm, with the peak at 475 nm. The PL band profile of sample B was similar to that of sample A. However, the peak position red-shifted to 490 nm. The PL from Zn2GeO4 nanorods was quite different from that of sintered Zn2GeO4 powder which not only exhibited green PL peaked at 530 nm but also had a narrower FWHM. The luminescence of nanorods was rather likely associated with the native defects, and the red-shift phenomenon of PL peak may be correlated with the larger grain size.