Author: Anna May

Martí Gich and Adrián Carretero-Genevrier publised a scientific video on the Journal of Visualized Experiments (JoVE), a peer-reviewed scientific video journal, on December 21, 2015. 

The video, entitled “Preparation of macroporous epitaxial quartz films on silicon by chemical solution deposition” (A Carretero-Genevrier, M Gich, JoVE (Journal of Visualized Experiments), e53543-e53543, 12/21/2015, Issue 106; DOI: 10.3791/53543) presents the protocol for the preparation of piezoelectric macroporous epitaxial films of quartz on silicon by soft chemistry using dip-coating and thermal treatments in air. 

Abstract:

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step process based on the preparation of a sol in a one-pot synthesis which is followed by the deposition of a gel film on Si(100) substrates by evaporation induced self-assembly using the dip-coating technique and ends with a thermal treatment of the material to induce the gel crystallization and the growth of the quartz film. The formation of a silica gel is based on the reaction of a tetraethyl orthosilicate and water, catalyzed by HCl, in ethanol.

However, the solution contains two additional components that are essential for preparing mesoporous epitaxial quartz films from these silica gels dip-coated on Si. Alkaline earth ions, like Sr²⁺ act as glass melting agents that facilitate the crystallization of silica and in combination with cetyl trimethylammonium bromide (CTAB) amphiphilic template form a phase separation responsible of the macroporosity of the films. The good matching between the quartz and silicon cell parameters is also essential in the stabilization of quartz over other SiO₂ polymorphs and is at the origin of the epitaxial growth.