Toyota

About: Toyota is a company organization based out in Safenwil, Switzerland. It is known for research contribution in the topics: Internal combustion engine & Battery (electricity). The organization has 40032 authors who have published 55003 publications receiving 735317 citations. The organization is also known as: Toyota Motor Corporation & Toyota Jidosha KK.

Electronic structure and physical properties of early transition metal mononitrides: Density-functional theory LDA, GGA, and screened-exchange LDA FLAPW calculations

Abstract: The desirable physical properties of hardness, high temperature stability, and conductivity make the early transition metal nitrides important materials for various technological applications. To learn more about the nature of these materials, first-principles density-functional theory calculations using the full-potential linearized augmented plane wave (FLAPW) method within the local-density approximation (LDA) and with the generalized gradient approximation (GGA) have been performed. We investigate the bulk electronic and physical properties of a series of early transition metal mononitrides, namely, those formed with 3d metals (ScN, TiN, VN), 4d metals (YN, ZrN, NbN), and 5d metals (LaN, HfN, TaN) in the rocksalt structure. In particular, lattice constants, bulk moduli, heats of formation, and cohesive energies as well as bulk band structures and densities of states are reported, and trends discussed. We find that the GGA yields 1%--2% larger lattice constants, 10%--20% smaller bulk moduli, and 10%--30% lower heats of formation compared to the LDA. The GGA slightly overestimates lattice constants, but leads overall to an improved agreement with experiment compared to the LDA, for which the values are too small. These materials are metallic with the exception of ScN, YN, and LaN, which appear to be semimetals within the LDA (and GGA), but are in fact semiconductors with indirect band gaps of 1.58, 0.85, and 0.75 eV, respectively, as revealed by calculations performed using the screened-exchange LDA approach. These last, relatively unexplored, refractory III-V nitrides may therefore have potential use in device applications; in particular, ScN is well lattice matched to GaN, a wide-band-gap semiconductor that is of great current interest in relation to optoelectronic devices, and high temperature and high power electronic applications.

Metal oxides as a hole-injecting layer for an organic electroluminescent device

Abstract: We demonstrate that by using thin films of metal oxides, such as vanadium oxide (VOx), molybdenum oxide (MoOx) and ruthenium oxide (RuOx), as a hole-injecting layer for an organic electroluminescent (EL) device consisting of N,N'-diphenyl-N,N-bis(3-methylphenyl1)1,1'-biphenyl-4,4' diamine (TPD) and tris-(8-quinolinolato) aluminium (Alq), the EL device performance can be significantly improved. The `operating voltage' of the device is reduced with respect to a device with a well known indium - tin-oxide (ITO) electrode for hole injection. We consider that the improvement of the operating voltage is attributable to the lower energy barrier for hole injection at the metal oxide/TPD interface.

Selective CO2 Conversion to Formate Conjugated with H2O Oxidation Utilizing Semiconductor/Complex Hybrid Photocatalysts

Abstract: Photoelectrochemical reduction of CO2 to HCOO– (formate) over p-type InP/Ru complex polymer hybrid photocatalyst was highly enhanced by introducing an anchoring complex into the polymer By functionally combining the hybrid photocatalyst with TiO2 for water oxidation, selective photoreduction of CO2 to HCOO− was achieved in aqueous media, in which H2O was used as both an electron donor and a proton source The so-called Z-scheme (or two-step photoexcitation) system operated with no external electrical bias The selectivity for HCOO− production was >70%, and the conversion efficiency of solar energy to chemical energy was 003–004%