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Obtaining semiconducting properties that meet practical standards for p-type transparent oxide semiconductors is challenging due to the balance between the defects that generate hole and electron carriers. Here, we demonstrate that modulating the individual thermodynamic and kinetic conditions during the growth of p-type oxide SnO films is beneficial in tailoring their semiconducting properties. By tuning the growth temperature and laser fluence for pulsed laser deposition, the hole carrier density dramatically changes from approximately 4 × 10 16 to 6 × 10 18 cm −3 at room temperature. The room-temperature hole mobility (μ) strongly depends on the carrier density (n), and their relationship is like a "volcano-shaped" curve. This suggests the competition between several scattering sources, such as the ionized impurity scattering (μ ∝ n −1 ), and grain boundary and/or dislocation scattering (μ ∝ n 0.5 ) for higher and lower n, respectively. The hole mobility is enhanced to approximately 21 cm 2 V −1 s −1 at room temperature, which is the highest recorded for SnO films to date. These findings provide important guidelines for designing all-oxide transparent electronic devices.

Stannous oxide, SnO, is a promising material for practical applications as a p-type transparent oxide semiconductor. The hole mobility of SnO epitaxial films grown by pulsed laser deposition can be improved by reducing the growth temperature.

Wide-gap oxides with their valence band maximum (VBM) composed of s orbitals are essential for realizing practical p-type transparent oxide semiconductors. We prepared a new p-type wide-gap oxide, SnNb2O6 foordite, with its VBM composed of Sn 5s orbitals. To discuss carrier generation, we prepared both p-type and n-type SnNb2O6 by controlling the annealing conditions. The carrier mobility and density were 3.8 × 10–1 cm2 V–1 s–1 and 3.7 × 1018 cm–3, respectively, for the p-type sample and 9.9 cm2 V–1 s–1 and 7.5 × 1015 cm–3, respectively, for the n-type sample. The crystal structure of SnNb2O6 foordite consists of two types of alternating layers, Sn and Nb2O6 octahedra, where three nonequivalent oxygen sites exist. Six oxygens in the chemical formula of SnNb2O6 are distributed at the three sites in pairs, where the oxygens in three nonequivalent sites were named O1–O3. Hole and electron carriers were considered to be generated by Sn4+-on-Nb5+ substitutional defects (SnNb ′) and oxygen vacancies of O1 and O2 that are not bonded to Sn (VO1/O2 ••), respectively. Therefore, we concluded that it is essential to control SnNb ′ and VO1/O2 •• to control the semiconducting properties such as the carrier type and carrier density.

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We used an rf magnetron reactive sputtering method to prepare SrMoO3 thin film on a silica glass substrate and evaluated its optical properties. The reflectivity of the blue-colored film showed a cutoff due to plasmon at ∼1.7 eV. From a Kramers–Kronig analysis of the reflectivity, the spectral dependence of dielectric constants and optical constants were obtained. They agreed in tendency with the constants determined by spectroscopic ellipsometry. The plasma frequency due to free carriers (4.5 eV) was obtained by application of a Drude model to reflectivity values, which showed that the effective mass of the conduction carrier was m*=2.1m0, where m0 is the free electron mass.

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