Structure and Optical Properties of Ca Silicide Films and Si/Ca₃Si₄/Si(111) Heterostructures

Abstract:

Thick, thin films and island of Ca silicide have been grown by Ca deposition onto 500 °C Si (111)7x7 substrates. The crystal structure of the grown layers strongly differs from the known Ca silicides (Ca₂Si, CaSi, Ca₅Si₃, Ca₁₄Si₁₉, CaSi₂). The phonon peaks at 389 and 416 cm^-1 and the interband transition peaks (0.9-1.0, 1.3-1.7 and 2.0-2.5 eV) belongs to another silicide - Ca₃Si₄. Peculiarities of crystal, electronic, and phonon structure and optical properties of the grown Ca silicide films were measured by in situ and ex situ methods permit to state that the formed Ca silicide film has a composition Ca₃Si₄. Heterostructures with embedded Ca₃Si₄ films with different thicknesses have been formed atop the Ca₃Si₄ films by MBE and SPE at 500 °C. The observed density of pinholes with different sizes suggests the Si growth atop the Ca silicide follows a 3D mechanism. Photoluminescence was found first time in Si/Ca₃Si₄/Si (111) heterostructures.

• Periodical: Solid State Phenomena (Volume 213)
• Pages: 71-79
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.213.71
• Online since: March 2014
• Authors: Nikolay G. Galkin, Dmitrii Aleksandrovich Bezbabnyi*, Sergei Andreevich Dotsenko, Konstantin Nickolaevich Galkin, Igor Mikhailovich Chernev, Evgeniy Anatolievich Chusovitin, Peter Nemes-Incze, Laszlo Dózsa, Béla Pécz, Timur Sezgitovich Shamirzaev, Anton Konstantinovich Gutakovski
• Keywords: Ca₃Si₄, Crystal Structure, Double Heterostructures, Electronic Structure, Film, Optical Property, Phonon Structure, Silicon

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