Laser CVD of Nanodisperse Ge–Sn Alloys Obtained by Dielectric Breakdown of SnH₄/GeH₄ Mixtures

Abstract

TEA CO2 laser‐induced dielectric breakdown of an equimolar mixture of gaseous stannane and germane in Ar allows decomposition of both metal hydrides and chemical vapour deposition of the nanostructured Ge/Sn films. Analysis of the films by FTIR and Raman spectroscopy, X‐ray diffraction analysis and electron microscopy revealed nanoregions of crystalline Sn and Sn‐rich Ge/Sn alloys surrounded by an amorphous Ge/Sn phase. The crystalline Ge/Sn nanoalloys contain different amounts of Sn incorporated into the Ge lattice and undergo changes in composition at temperatures as low as 200 °C.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)

IR laser-induced CVD of β-Sn/SnSi-nanodisperse alloys from stannane–silane mixture

“…The presented results are an extension of our previous effort on (i) laser-induced gas-phase co-pyrolytic synthesis of inorganic compounds [21][22][23][24] and (ii) IR laser-dielectric breakdown-induced formation of Sn/Ge metastable films from gaseous stannane and germane [25].…”

“…Diffraction patterns were collected with a PANalytical X'Pert PRO diffractometer equipped with a conventional X-ray tube (Co Ka radiation, 40 kV, 30 mA, point focus), an X-ray monocapillary with diameter of 0.1 mm, and a multichannel detector X'Celerator with an anti-scatter shield through a procedure reported previously [25]. XRD patterns were not pre-treated before interpretation, as no background correction was needed.…”

“…10 0 0 transition (944.19 cm À1 ) and pulse energy 1.8 J. The gaseous mixture was irradiated in a Pyrex reactor [25] fitted with KBr windows and PTFE valve connecting to vacuum manifold and pressure transducer. The laser pulse was focused with a NaCl lens (f.l.…”

IR laser CVD of nanostructured Si/Ge alloy from silane–germane mixture

“…IR-laser irradiation experiments were conducted in a Pyrex reactor (70 mL in volume) reported previously [21]. Briefly, the reactor was a tube fitted at each end with KBr windows and having a PTFE valve connecting to vacuum manifold and pressure transducer.…”

“…We have recently used the TEA CO 2 laser for inducing (i) dielectric breakdown in tetramethylgermane/tetramethyltin mixtures to allow CVD of nanostructured Sn/Ge/C and Ge-Sn/C films [20] and (ii) infrared multiple-photon co-decomposition of two different metal hydrides (SnH 4 , GeH 4 or SiH 4 ) for CVD of nanodisperse Ge-Sn [21] and ␤-Sn/SnSi [22] alloys. These nanosized alloys are expected to have photoluminescence properties controlled by their composition [19] and can find applications in biology and medicine.…”