Search

Modified 241Am-Be neutron beams showed an ability to change the optical properties of zinc oxide (ZnO) photoluminescence (PL) spectra by transmuting zinc (Zn) into gallium (Ga) after irradiation. This study investigates the time required by slow neutron irradiation to register the transmutation of the Zn into Ga. Two series of samples from different suppliers hydrothermally (HT) grown by TEW Tokyo Denpa Co. Ltd., Tokyo, Japan, and MTI corporation, China, are irradiated for 6, 12, 18, and 24 days on the Zn-polar face of each sample to specify the relationship between the irradiation intensity and transmutation. [ABSTRACT FROM AUTHOR]

Photoluminescence is observed at room temperature from phonon-assisted band-to-band emission in Si (1.067eV peak) using unpatterned bulk p-type silicon wafer samples that were spin-coated with Er-doped (6at.%) silica-gel films (0.13μm) and vacuum annealed; the strongest emission was obtained at ∼700°C. Comparative study of annealing behavior indicates an efficiency enhancement of two orders of magnitude. Emission from Er3+ ions in the silica film is used to gauge relative emission strengths. Mechanisms for inducing emission from silicon utilizing stresses in sol–gel films are discussed. [Copyright &y& Elsevier]

Abstract: Techniques of film deposition by co-evaporation, ion-beam assisted mixing, oxygen ion implantation, and thermal annealing were been combined in a novel way to study processing of erbium-in-silicon thin-film materials for optoelectronics applications. Structures with erbium concentrations above atomic solubility in silicon and below that of silicide compounds were prepared by vacuum co-evaporation from two elemental sources to deposit 200–270nm films on crystalline silicon substrates. Ar+ ions were implanted at 300keV. Oxygen was incorporated by O+-ion implantation at 130keV. Samples were annealed at 600°C in vacuum. Concentration profiles of the constituent elements were obtained by Rutherford backscattering spectrometry. Results show that diffusion induced by ion-beam mixing and activated by thermal annealing depends on the deposited Si–Er profile and reaction with implanted oxygen. Room temperature photoluminescence spectra show Er3+ transitions in a 1480–1550nm band and integrated intensities that increase with the oxygen-to-erbium ratio. [Copyright &y& Elsevier]

Room-temperature 1535 nm band photoluminescence in [?]126 nm silica films (6 at% doping), produced by spin coating an Er2O3 and tetraethylorthosilicate sol-gel formulation on silicon substrates, was studied as a function of vacuum furnace annealing (500-1050 degC). Emission is strongly enhanced for annealing near 850 degC, which is shown by modelling the temperature dependence as arising from thermally activated removal of hydroxyl ions. Suitability of such a process for silicon-based applications is discussed. [ABSTRACT FROM AUTHOR]