Rutile-type Ge<sub> x </sub>Sn<sub>1−x </sub>O<sub>2</sub> alloy layers lattice-matched to TiO<sub>2</sub> substrates for device applications
Hitoshi Takane, Takayoshi Oshima, T. Harada, Kentaro Kaneko, Katsuhisa Tanaka
Abstract
Abstract We report the characterization and application of mist-CVD-grown rutile-structured Ge x Sn 1− x O 2 ( x = ∼ 0.53) films lattice-matched to isostructural TiO 2 (001) substrates. The grown surface was flat throughout the growth owing to the lattice-matching epitaxy. Additionally, the film was single-crystalline without misoriented domains and TEM-detectable threading dislocations due to the coherent heterointerface. Using the Ge 0.49 Sn 0.51 O 2 film with a carrier density of 7.8 × 10 18 cm −3 and a mobility of 24 cm 2 V −1 s −1 , lateral Schottky barrier diodes were fabricated with Pt anodes and Ti/Au cathodes. The diodes exhibited rectifying properties with a rectification ratio of 8.2 × 10 4 at ±5 V, showing the potential of Ge x Sn 1- x O 2 as a practical semiconductor.