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Gallium oxide (Ga 2 O 3) films have been deposited on SrTiO 3 (100) substrates by using the metal-organic chemical vapor deposition (MOCVD) method. Post-deposition annealing was performed at different temperatures. XRD θ -2 θ scans displayed that the annealing at 1000 °C leaded to β phase Ga 2 O 3 film with the best crystalline quality. Microstructural and chemical composition analyses revealed that this film was single crystal β -Ga 2 O 3 with stoichiometric ratio. The epitaxial relationships were clearly determined as β -Ga 2 O 3 (100) || SrTiO 3 (100) with β -Ga 2 O 3 [001] || SrTiO 3 <011>. All of the prepared Ga 2 O 3 samples have average transmittances in the visible range of more than 70%. [ABSTRACT FROM AUTHOR]

Ta-doped TiO2 (TiO2:Ta) films were synthesized on MgAl6O10 substrates by the metal-organic chemical vapor deposition (MOCVD) method. The doping uniformities, crystallization qualities, and optical properties of the deposited films were systematically characterized. The measurement results revealed the TiO2:Ta films with low Ta concentrations to be epitaxial anatase films with high transparency in the visible region. Thin-film transistors (TFTs) based on TiO2:Ta films were fabricated. The device with 0.5-at.% Ta-doped TiO2 as a channel layer exhibited clear n-type TFT behaviors with a high ${I} _{ \mathrm{\scriptscriptstyle ON}}/{I} _{ \mathrm{\scriptscriptstyle OFF}}$ ratio of $4.0\times 10^{{8}}$ , a low subthreshold swing of 0.60 V/decade, and a saturation mobility of 4.4 cm2V−1s−1. These parameters were superior to the values of previously reported TiO2-based devices and indicated that the Ta-doped TiO2 film was a promising channel material for transparent metal–oxide TFTs. [ABSTRACT FROM AUTHOR]

Epitaxial SnO 2 films were deposited on MgF 2 (110) substrates at different substrate temperatures by the metal organic chemical vapor deposition (MOCVD) method. The structural, optical and electrical properties as well as elementary composition were studied in detail. The obtained films were all rutile phase SnO 2 grown along the [110] direction. The SnO 2 film prepared at 660 °C was single crystalline epitaxial film. The epitaxial relationships were clearly determined as SnO 2 (110) || MgF 2 (110) with SnO 2 [001] || MgF 2 [001]. The Hall mobility of the 660 °C-deposited film was 21 cm 2 V −1 s −1 with a carrier concentration of 3.9 × 10 17 cm −3 . The average transmittance of the 660 °C-deposited film in the visible range is 93% and the optical band gap is estimated as 3.89 eV. [ABSTRACT FROM AUTHOR]

• Epitaxial Ta-doped SnO 2 films were successfully deposited on Al 2 O 3 (012) substrates by MOCVD. • The structural, electrical and optical properties of the obtained films were investigated. • The highest Hall mobility of 58.1 cm2 V−1 s−1 was achieved for the 4 at.% Ta-doped SnO 2 film. • The average transparency of the obtained Ta-doped SnO 2 films exceeded 88% in the visible region. • With Ta concentration increasing from 0 to 8 at.%, the transparent range of the films extended to the UV-B light region (280–320 nm). Tantalum (Ta)-doped SnO 2 films with different Ta concentrations have been deposited on α- Al 2 O 3 (012) substrates by the metal organic chemical vapor deposition (MOCVD) method at 620 °C. Structural, electrical and optical properties of the obtained films have been investigated in detail. Structural analyses revealed that all the obtained films were rutile SnO 2 growing along SnO 2 [101] orientation. The 4% Ta-doped SnO 2 film exhibited the best crystal quality and the in-plane epitaxial relationship between the film and substrate was SnO 2 [010]//Al 2 O 3 [110]. The highest Hall mobility of 58.1 cm2 V−1 s−1 was achieved for the 4 at.% Ta-doped SnO 2 film and the minimum resistivity as low as 4.0 × 10-4 Ω cm was obtained at 6 at.% of Ta doping concentration. In the visible light region, all the obtained films showed average transmittances exceeding 88%. With Ta concentration increasing from 0 to 8 at.%, the transparent range of the films extended to the UV-B light region (280–320 nm), while the optical band gap of the films rose from 3.96 to 4.30 eV. [ABSTRACT FROM AUTHOR]

Rutile SnO2 epitaxial films are deposited on MgF2 (001) substrates at different substrate temperatures (540–660 °C) by metal organic chemical vapor deposition. Structural, optical, and electrical properties of the films as well as the epitaxial mechanism are investigated in detail. The structure analyses manifest that the film deposited at 620 °C is rutile phase SnO2 and exhibits the best crystallinity. The epitaxial relationships are determined as SnO2 (110) || MgF2 (001) with SnO2 [001] || MgF2 [110] and [1¯10]. The Hall mobility, resistivity, and carrier concentration of the 620 °C‐deposited film are 10.4 cm2 · V−1 · s−1, 0.75 Ω · cm, and 8.1 × 1017 cm−3 respectively. The average transmittance in the visible range of the SnO2 film deposited at 620 °C exceeds 88% and the optical band gap is about 3.93 eV. High‐quality epitaxial rutile SnO2 films are successfully deposited on single crystalline MgF2 (001) substrate for the first time by metal organic chemical vapor deposition. The average transmittance of all SnO2 films in the visible range exceeds 86%. The structural, electrical, and optical properties are investigated in detail. The samples show temperature‐dependent structural and electrical properties. The epitaxial mechanism is also proposed. [ABSTRACT FROM AUTHOR]