Crystal phase-selective epitaxy of Nb-doped TiO2 (TiO 2:Nb) films on GaN is demonstrated using the helicon-wave-excited- plasma sputtering epitaxy method. On the clean (0001) GaN, rutile (100) TiO 2:Nb was grown regardless of growth temperature (Tg). On the (0001) GaN covered with a monolayer-thick (100) or (001) β-Ga 2O3, anatase (001) TiO2:Nb was grown with the in-plane relation 〈110〉TiO2 || 〈112̄0〉GaN under high Tg and low O2 partial pressure conditions. The transmittance between 450 and 900nm for the 200-nm-thick films was approximately 80%. Typical resistivity of the anatase TiO2:Nb/GaN heterostructure was as low as 3.6 × 10-4 ω.cm, due to the interfacial conduction.
ASJC Scopus subject areas
- Physics and Astronomy(all)