No abstract

Porous silicon carbide has been fabricated using single crystal 6H-SiC that has a wider indirect band gap than silicon crystal. Intense blue-green luminescence has been observed at room temperature. The peak wavelength is around 460 nm, below the band gap of crystalline SiC. The luminescence intensity is about 100 times stronger than that of crystalline 6H-SiC. These results not only clarify the origin of luminescence in porous Si but also point to the possibility of the use of this new material for an intense blue-green luminescent source.

We have investigated the defect structure in bismuth titanate (Bi4Ti3O12) through high-temperature neutron powder diffraction analysis and ab-initio electronic structure calculations. It is shown that the vacancies of Bi and oxide ions are created preferentially in the perovskite layers rather than in the Bi2O2 layers. Measurements of the leakage-current properties of the single crystals demonstrate that electron holes arising from the incorporation of oxygen at the vacancies of oxide ions act as detrimental carriers for electrical conduction at room temperature. A crystal growth under high oxygen pressure is proposed to be advantageous for suppressing the vacancy formation and for attaining a large remanent polarization as well as a high insulating property of the Bi4Ti3O12 system.

Nanoantenna-like properties of sea-urchin shaped ZnO as a nanolight filter Appl. Phys. Lett. 101, 133101 (2012) Leaky mode analysis of luminescent thin films: The case of ZnO on sapphire J. Appl. Phys. 112, 063112 (2012) ZnO/ZnSxSe1−x core/shell nanowire arrays as photoelectrodes with efficient visible light absorption Appl. Phys. Lett. 101, 073105 (2012) Study of the photoluminescence emission line at 3.33eV in ZnO films

No abstract