Optical properties of single crystalline SrMoO3 thin films

Abstract

The optical properties of pulsed laser deposited highly crystalline SrMoO3 thin films were investigated. Due to their low resistivity below 30 μΩ cm, thin films of SrMoO3 are candidates for transparent conductor applications. The transparency of SrMoO3 extends into the ultraviolet range to about 300 nm. In this range, SrMoO3 has a higher transparency at similar sheet resistance as compared to alternative oxide or metallic materials. Density functional theory shows that electron-electron correlation effects are small in SrMoO3 as compared to other low-resistivity transition metal oxides and predicts the optical properties in good agreement with experiment.

Chemical Control of Correlated Metals as Transparent Conductors

“…Ellipsometry measurements (Figure S4, Supporting Information) were fitted with a combination of Drude and Lorentz oscillators (Table S1, Supporting Information) to extract the complex dielectric function presented in Figure c. The reduced plasma energy ω p , defined as the energy at which the real part of the complex dielectric function ε 1 is equal to zero, is measured as 1.73 eV (purple dashed–dotted line in the top panel of Figure c), consistent with previous reports giving a value between 1.75 and 2.0 eV . This shift of the plasma frequency toward the visible compared to SrVO 3 (arrow in top panel Figure c) make SrMoO 3 an ideal system to maximize the conductivity.…”

“…Dense ceramic targets of SrMoO 4 and CaMoO 4 were prepared via conventional solid state synthesis. A reducing environment of 2.5% H 2 in Ar was used at 0.3 mTorr in order to reduce the Mo 6+ oxidation state of the target to the Mo 4+ state of the targeted perovskite phase as demonstrated in previous reports . A nominal substrate temperature of 650 °C was used with a laser fluence of 1.3 J cm −2 at a rate of 1 Hz.…”

Molecular beam epitaxy growth of the highly conductive oxide SrMoO3

“…The room temperature (RT) resistivity ρ of singlecrystalline SrMoO 3 is as low as 5 µΩ cm, which is much lower than typical oxide materials 4 and is rather close to those of nearly free electron systems such as sodium and copper. The utmost feature of this oxide has stimulated intensive studies to grow epitaxial films [5][6][7][8][9] for applications, for example, electrodes between oxide interfaces 5,10 and transparent conductors 6,11 . Unfortunately, all the films, so far prepared by pulsed laser deposition (PLD) [7][8][9][10][11][12] or sputtering 5,6 , show rather poor resistivity (27-150 µΩ cm) than that of the bulk single crystal, possibly due to the presence of defects or inclusion of impurity phases.…”

“…Unfortunately, all the films, so far prepared by pulsed laser deposition (PLD) [7][8][9][10][11][12] or sputtering 5,6 , show rather poor resistivity (27-150 µΩ cm) than that of the bulk single crystal, possibly due to the presence of defects or inclusion of impurity phases. It is notable that an insulating Mo 6+ phase is often found in the surface state [10][11][12] .…”

Persistent metallic Sn-doped In2O3 epitaxial ultrathin films with enhanced infrared transmittance

“…2f. To avoid the contribution of the substrate to the transmittance of ITO, we extracted the transmittance T (=I t /I 0 ) by normalizing the intensity I t transmitted through the ITO film and the YSZ substrate to the I 0 of the bare YSZ substrate 20 . We examined the feasibility of IR-TEs on the basis of T > 65% at a wavelength of 2.5 μm and sheet resistance R s < 400 Ω □ −1 at room temperature, as highlighted in the graded blue colour [although we investigated the transmittance up to the wavelength of 10 μm, we compared the data at 2.5 μm since most TE materials showed transmittance below 2.5 μm].…”