Tin Oxide (SnO2)

Tin Oxide (SnO₂) reveals typical features of wide bandgap transparent semiconducting oxides (TSOs), i.e., n-type semiconducting behavior with high electron mobility and high transparency in the visible spectrum. High thermal instability of SnO₂ promotes, therefore, the growth from the gas phase, as it can be easily converted into gas phase. The SnO₂ crystals obtained by Z. Galazka et al. on the sapphire substrates had usually low-angle grain boundaries that are formed likely by coalescence of individual SnO₂ prisms on sapphire substrate, the density of which decreases with distance from the substrate, or even vanish. The Ir substrate holder on the crucible top was in the form of a ring with a recess of 30 mm in diameter to accommodate the substrate and a central opening of 25 mm facing the SnO₂ starting material. The stability of SnO₂ surfaces and their selection are important for epitaxial growth, gas sensing, and catalytic properties.