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Few materials have been identified as high-performance transparent conductors in the visible regime (400–700 nm). Even fewer conductors are known to be transparent in ultraviolet (UV) spectrum, especially at wavelengths below 320 nm. Doped wide-bandgap semiconductors employed currently as UV transparent conductors have insufficient electrical conductivities, posing a significant challenge for achieving low resistance electrodes. Here, we propose SrNbO3 as an alternative transparent conductor material with excellent performance not only in the visible, but also in the UV spectrum. The high transparency to UV light originates from energetic isolation of the conduction band, which shifts the absorption edge into the UV regime. The standard figure of merit measured for SrNbO3 in the UV spectral range of 260–320 nm is on par with indium tin oxide in the visible, making SrNbO3 an ideal electrode material in high-performance UV light emitting diodes relevant in sanitation application, food packaging, UV photochemotherapy, and biomolecule sensing. Optically transparent electrodes with high electrical conductance are essential for the implementation of optoelectronics, but current technology performs poorly in the ultraviolet regime. Here, SrNbO3 is proposed as an alternative material due to its high figure of merit in the ultraviolet range. [ABSTRACT FROM AUTHOR]

We investigated the photocurrent-voltage characteristics of pentacene field effect transistors in order to study the gap state distribution and carrier generation mechanism. In top-contact devices, the photocurrent spectrum versus photon energy exhibited the typical Urbach tail, while such a tail was not observed in bottom-contact devices. The formation of this Urbach tail can be explained by assuming that diffused gold nanoparticles at the gold/pentacene interface cause microfields and stabilize the excitons. This mechanism also provides an explanation for the reduced barrier height and Ohmic contact formation at “dirty” interfaces fabricated by metal deposition. [ABSTRACT FROM AUTHOR]

We have investigated the Faraday spectra of ferromagnetic rutile Ti1-xCoxO2-δ films grown on Al2O3 (0001). The Faraday spectra strongly depended on the film thickness, revealing the significant effect of the multiple reflections of light. The intrinsic Faraday spectra of rutile Ti1-xCoxO2-δ were corrected for this multiple reflection effect on the basis of an optical model and compared with the absorption spectra in detail. The quantitatively good correspondence between intrinsic Faraday ellipticity and optical band edge strongly suggests that rutile Ti1-xCoxO2-δ is an intrinsic ferromagnetic semiconductor. The exchange parameters, N0α and N0β, were estimated as the order of ∼0.1 eV. [ABSTRACT FROM AUTHOR]

This Letter focuses on the discovery of a transparent conducting oxide (TCO), anatase Ti1-xNbxO2 films with x=0.002–0.2. The resistivity of films with x>=0.03 is 2–3×10-4 Ω cm at room temperature. The carrier density of Ti1-xNbxO2 can be controlled in a range of 1×1019 to 2×1021 cm-3. The internal transmittance for films with x≤=0.03 (40 nm thickness) is about 97% in the visible light region. The transport and optical parameters are comparable to those of typical TCOs, such as In2-xSnxO3 and ZnO [ABSTRACT FROM AUTHOR]

We have synthesized magnetic Fe-doped NiGa2S4 and investigated its electrical and magnetic properties with a superconducting quantum-interference device magnetometer, Mössbauer spectroscopy, and a physical property measurement system. X-ray diffraction analysis at room temperature shows that the prepared samples are single phase with trigonal structure (P-3m1). From zero-field-cooled (ZFC) and field-cooled magnetization curves under 100 Oe between 4.2 and 200 K, we have measured the temperature-dependent susceptibility χ of Ni1-xFexGa2S4. A cusp is observed in the ZFC measurement for the samples with x ≥ 0.1, which is due to the spin-freezing effect in the spin-glass system. Moreover, with increasing Fe concentration, the sample shows the antiferromagnetic behavior and the increase in freezing temperature Tf. This, in turn, suggests that the spin-averaged value of the sample increases and antiferromagnetic spin-spin interaction becomes stronger with Fe concentration. The temperature-dependent resistance of semiconducting Ni1-xFexGa2S4 (x = 0.3, 0.5, 0.7, 0.9) follows Arrhenius law R = R0exp(E0/kBT) for the semiconducting temperature, with the gap energies E0 of 210.6, 192.0, 135.6, and 126.4 meV, respectively. This increase in gap energy comes from the distortion of octahedral structure in the a-b plane direction. [ABSTRACT FROM AUTHOR]

We have investigated the Faraday spectra of ferromagnetic rutile Ti1-xCoxO2-δ films grown on Al2O3 (0001). The Faraday spectra strongly depended on the film thickness, revealing the significant effect of the multiple reflections of light. The intrinsic Faraday spectra of rutile Ti1-xCoxO2-δ were corrected for this multiple reflection effect on the basis of an optical model and compared with the absorption spectra in detail. The quantitatively good correspondence between intrinsic Faraday ellipticity and optical band edge strongly suggests that rutile Ti1-xCoxO2-δ is an intrinsic ferromagnetic semiconductor. The exchange parameters, N0α and N0β, were estimated as the order of ∼0.1 eV. [ABSTRACT FROM AUTHOR]

This Letter focuses on the discovery of a transparent conducting oxide (TCO), anatase Ti1-xNbxO2 films with x=0.002–0.2. The resistivity of films with x>=0.03 is 2–3×10-4 Ω cm at room temperature. The carrier density of Ti1-xNbxO2 can be controlled in a range of 1×1019 to 2×1021 cm-3. The internal transmittance for films with x≤=0.03 (40 nm thickness) is about 97% in the visible light region. The transport and optical parameters are comparable to those of typical TCOs, such as In2-xSnxO3 and ZnO [ABSTRACT FROM AUTHOR]