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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]

Abstract Epitaxial Ta-doped SnO 2 films with Ta concentrations from 0 to 8 at.% have been deposited on MgF 2 (110) substrates by the metal-organic chemical vapor deposition (MOCVD) method. The effects of Ta doping on the structural, photoelectrical and photoluminescence (PL) properties of the obtained films were studied in detail. The results showed that the single crystal rutile SnO 2 films were obtained and the heteroepitaxial relationship was SnO 2 (110) || MgF 2 (110) with SnO 2 [001] || MgF 2 [001]. The highest Hall mobility of 74.2 cm2 V−1 s−1 was achieved for the 5 at.% Ta-doped SnO 2 film and the minimum resistivity as low as 2.5 × 10−4 Ω cm was obtained at 6 at.% of Ta-doping. In the visible region, all the obtained films had average transmittances exceeding 87%. As the Ta concentration increased from 0 to 8 at.%, the optical band gap of the films rose from 3.89 to 4.32 eV. The room temperature PL spectra of Ta-doped SnO 2 films showed intense green emission, weak violet and yellow emissions. The corresponding PL mechanisms were discussed. [ABSTRACT FROM AUTHOR]

Abstract Undoped and tantalum-doped titania (TiO 2 :Ta) films were synthesized via metalorganic chemical vapor deposition (MOCVD). The crystallization qualities, surface morphologies and optical properties of the deposited films were systematically characterized. The results indicated that the films having low doping levels were epitaxial anatase titania along [001] orientation with high transparency in visible region. The optical band gap could be modulated from 3.38 to 3.52 eV by controlling Ta doping levels. Ultraviolet (UV) photoelectric detectors with metal-semiconductor-metal (MSM) structure were designed and fabricated based on the undoped and Ta-doped films. The maximum spectral response of 32.3 A/W was detected at about 315 nm for the 1% Ta-doped TiO 2 film-based detector. The detectors based on the undoped and 1% Ta-doped TiO 2 films also presented good temporal responses and visible-blind characteristics, showing excellent UV light detection performances. [ABSTRACT FROM AUTHOR]

Gallium oxide (Ga 2 O 3 ) films were grown on epi-GaN/sapphire (0001) substrates by the metalorganic chemical vapor deposition (MOCVD) method, followed by a post-deposition thermal annealing at different temperatures of 800, 900 and 1000 ℃ for one hour in air. X-ray diffraction (XRD, both θ ~2 θ and Φ scans) and transmission electron microscopy (TEM) were used to inspect the lattice structure and epitaxial relationship. With the increase of annealing temperature, the film structure changed from amorphous to single crystalline and then to polycrystalline. A single crystalline β -Ga 2 O 3 film with the best crystalline quality was obtained under the annealing condition at 900 ℃, and a clear epitaxial relationship of β -Ga 2 O 3 (100)‖GaN(0001) with β -Ga 2 O 3 < 010 > ‖GaN < 1 ¯ 2 1 ¯ 0 > and β -Ga 2 O 3 < 001 > ‖GaN < 1 ¯ 010 > was determined. The elemental composition and proportion of the 900 ℃-annealed film were investigated by the X-ray photoelectron spectroscopy (XPS) measurements and the atomic ratio of Ga/O was about 0.69, which was close to stoichiometric Ga 2 O 3 . For the sample annealed at 900 ℃, the average transmittance in the visible wavelength region was about 78% and the average reflectivity in the 200–800 nm wavelength range was about 18%. [ABSTRACT FROM AUTHOR]

Ga 2 O 3 films were deposited on gadolinium gallium garnet (Gd 3 Ga 5 O 12 , or GGG)(110) substrates by the metalorganic chemical vapor deposition (MOCVD) method, followed by a post-deposition thermal annealing at different temperatures. The structural analyses showed that the film annealed at 900 ℃ was pure β -Ga 2 O 3 have the best crystalline quality. A clear epitaxial relationship of β -Ga 2 O 3 (100)‖GGG(110) with β -Ga 2 O 3 [010]‖GGG[00 1 ¯ ] was determined and a schematic diagram was proposed to clarify the growth mechanism for the 900 ℃-annealed sample. The average transmittance of the sample annealed at 900 ℃ was 84% in the visible wavelength region. A broad ultraviolet-green photoluminescence (PL) band ranged from 330 to 520 nm was observed, for which the PL mechanism was discussed and clarified. [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]

Ga 2 O 3 films were deposited on (100) oriented KTaO 3 substrates by the metal-organic chemical vapor deposition technology. Structural and chemical composition analyses confirmed that the as-deposited film at 850 °C was β phase Ga 2 O 3 with high crystalline quality. The epitaxial relationships between the film and substrate were determined as β -Ga 2 O 3 (100) || KTaO 3 (100) with β -Ga 2 O 3 [001] || KTaO 3 〈011〉 by X-ray diffraction, high resolution transmission electron microscopy and selected area electron diffraction results. The average transmittance in the visible range of the sample prepared at 850 °C was 73.6%, and the optical band gap of the β -Ga 2 O 3 film was approximately 4.79 eV with a resistivity of 5.01 × 103 Ω·cm. Unlabelled Image • Successfully prepared high crystalline quality β -Ga 2 O 3 films on KTaO 3 (100) substrates by MOCVD for the first time. • We obtained a very narrow FWHM value in the XRD ω -rocking scan of the prepared β -Ga 2 O 3 hetero-epitaxial film. • The epitaxial mechanism, optical properties and electrical properties of the Ga 2 O 3 samples were systematically investigated. • The lattice arrangements and elements distribution across the interface were observed by HRTEM and EDS, respectively. • The prepared β -Ga 2 O 3 film not only has high crystalline quality, but also has good optical and electrical properties. [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]

This paper focuses on the investigation of V/ITO (O 2 Rapid Thermal Annealing)-based Self-Selective Resistive Random-Access Memory (RRAM) device. In this study, the natural oxidation of Vanadium top electrode and the rapid thermal annealing (RTA) process greatly simplified the device fabrication process. The VO 2 -based Selector, formed by the natural oxidation of the Vanadium electrode, effectively suppresses current and is directly integrated with the ITO layer, eliminating the need for additional serial Selector. The oxygen content of the ITO film is significantly increased by the RTA process, enabling the previously conductive ITO material to be used as the RRAM insulating layer without the need for additional deposition of insulating layer. This V/ITO (O 2 RTA) structure not only exhibits highly uniform resistance distributions (σ/μ<2.8 %) and endurance stability (10000 cycles), but also effectively simulates synaptic plasticity, exhibiting both short-term and long-term memory behaviors. Notably, potentiation and depression characteristics are displayed by the device when continuous pulse voltage is applied. These advancements underscore the innovation and applicability of RTA-treated ITO films in next-generation memory technologies. [ABSTRACT FROM AUTHOR]

Titania (TiO 2 ) films with different niobium (Nb) doping concentrations were deposited on SrTiO 3 (STO) (100) substrates by metalorganic chemical vapor deposition (MOCVD). The crystal structures, surface morphologies, electrical and optical properties of the Nb-doped TiO 2 (TiO 2 :Nb) films varying with Nb content were investigated. The single crystal TiO 2 films with anatase structure were obtained at low Nb doping levels. The highest Hall mobility of the prepared films reached as high as 16.50 cm 2  V −1  s −1 . The lowest resistivity of 5.75 × 10 −2  Ω cm with a Hall mobility of 7.40 cm 2  V −1  s −1 and a carrier concentration of 1.47 × 10 19  cm −3 were obtained from the 1.20% Nb-doped TiO 2 film. This resistivity was about 6 orders of magnitude lower than the undoped TiO 2 film. Moreover, all the deposited films exhibited high average transmittances of over 88% in the visible wavelength range. [ABSTRACT FROM AUTHOR]

Titanium dioxide (TiO 2 ) films doped with different indium (In) concentrations have been prepared on SrTiO 3 (STO) substrates by high vacuum metalorganic chemical vapor deposition (MOCVD). X-ray diffraction (XRD) analyses revealed the TiO 2 films doped with low In concentrations to be [001] oriented anatase phase and the films with high In concentrations to present polycrystalline structures. The 1.8% In-doped TiO 2 film exhibited the best electrical conductivity properties with the lowest resistivity of 8.68×10 −2 Ω cm, a Hall mobility of 10.9 cm 2 V −1 s −1 and a carrier concentration of 6.5×10 18 cm −3 . The films showed excellent transparency with average transmittances of over 85% in the visible range. [ABSTRACT FROM AUTHOR]