IR laser‐induced synthesis of nanostructured gemanium telluride in the gas phase

The gas‐phase synthesis and chemical vapour deposition of nanostructured germanium telluride has been achieved for the first time. The pulsed IR laser irradiation of gaseous CH₃)₄Ge? (CH₃)₂Te? SF₆ mixtures results in homogeneous decomposition of both organometallics and formation of GeTe_x (x = 1, 2). The amorphous GeTe₂ and crystalline GeTe were identified by Raman and X‐ray photoelectron spectroscopy and by electron diffraction. Their formation is explained by an intermediacy of germanium and tellurium clusters and by reaction between these clusters in a hot laser‐induced zone. Copyright © 2005 John Wiley & Sons, Ltd.     

Laser‐induced dielectric breakdown in tetramethylgermane/tetramethyltin mixtures: deposition of nanostructured Sn/Ge/C and Ge?Sn/C films

Transversely Excited Atmospheric (TEA) CO₂ laser‐irradiation of gaseous tetramethylgermane (TMG)–tetramethyltin (TMT) mixtures in Ar results in decomposition of both organometallic compounds and in chemical vapour deposition of nanostructured films analyzed by FTIR and Raman spectroscopy, X‐ray diffraction and electron microscopy. They were shown to have similar morphology and elemental composition and constituents dependent on the TMG–TMT ratio. The analyses confirm the presence of nanosized carbon‐rich (graphitic) structures that incorporate C? M and M? M (M ?Ge, Sn) bonds containing an amorphous phase together with crystalline, either β‐Sn or metastable Sn‐rich Ge? Sn alloy. The unique latter constituent is favored at high concentrations of TMG precursor. Copyright © 2010 John Wiley & Sons, Ltd.