Chemical Solution Routes to Single-Crystal Thin Films
F. F. Lange
Epitaxial thin films of inorganic single crystals can be grown on
single-crystal substrates with a variety of different solution
chemistries. This review emphasizes chemical solution deposition, in
which a solution is used to deposit a layer of precursor molecules that
decompose to low-density, polycrystalline films during heating. Ways to
control film cracking during deposition and heat treatment and why many
precursors synthesize metastable crystalline structures are discussed,
and the different mechanisms that convert the polycrystalline film into
a single crystal are reviewed. Hydrothermal epitaxy, in which single
crystal thin films are directly synthesized on templating substrates in
an aqueous solution at temperatures <150°C, is also discussed.
The author is in the Materials Department, University of
California, Santa Barbara, CA 93106, USA.
