Structural investigations of Ge nanoparticles embedded in an amorphous SiO2 matrix

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology 2011, Vol.13 (1), p.221-232
• Main Authors: Stavarache, Ionel, Lepadatu, Ana-Maria, Gheorghe, Nicoleta G., Costescu, Ruxandra M., Stan, George E., Marcov, Dan, Slav, Adrian, Iordache, Gheorghe, Stoica, Tionica F., Iancu, Vladimir, Teodorescu, Valentin S., Teodorescu, Cristian M., Ciurea, Magdalena Lidia
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; High pressure; Inorganic Chemistry; Lasers; Materials Science; Nanoparticles; Nanotechnology; Optical Devices; Optics; Photonics; Physical Chemistry; Research Paper; Thin films
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-010-0021-4

Transmission electron microscopy and X-ray photoelectron spectroscopy analyses are performed to investigate Ge nanoparticles embedded in an amorphous SiO 2 matrix. GeSiO thin films are prepared by two methods, sol–gel and radio frequency magnetron sputtering. After the deposition, the sol–gel films are annealed in either N 2 (at 1 atm and 800 °C) or H 2 (at 2 atm and 500 °C), and the sputtered films in H 2 (at 2 atm and 500 °C), to allow Ge segregation. Amorphous Ge-rich nanoparticles (3–7 nm size) are observed in sol–gel films. Crystalline Ge nanoparticles in the high pressure tetragonal phase (10–50 nm size) are identified in the sputtered films. The size of the nanoparticles increases with Ge concentration in the volume of the film. At the film surface, the Ge concentration is much larger that in the volume for both sol–gel and sputtered films. At the same time, at the film surface, only oxidized Ge is observed.