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Abstract: In this paper, a shift in the photoluminescence (PL) peak from blue to near-infrared region was observed in the Si+-implanted 400-nm-thick SiO2 films with the rapid thermal annealing (RTA) method only. As the Si+-fluence was 1×1016 ions/cm2, a blue band was observed in the films after RTA at 1050°C for 5s in dry-N2 atmosphere; then, the band shifted from blue to orange upon increasing the holding temperature of RTA to 1250°C in the films after the isochronal RTA in dry N2. Furthermore, while the fluence was increased to 3×11016 ions/cm2 and the holding temperature was at the same range between 1050 and 1250°C, the PL peak occurred between red and near-infrared regions. Although the RTA and conventional thermal annealing (CTA) methods produce a similar mechanism, the CTA method needs a much longer annealing-time and a higher Si+-implanted dose than the RTA method for producing the same shift and intensity of PL peak from the as-implanted sample. Therefore, the RTA method can produce the mechanism in the Si+-implanted sample with the PL energy between blue and near-infrared band in place of the CTA method. [Copyright &y& Elsevier]

Abstract: In this study, nano-scale precursors of ZnO, SiO2, and MnO2 powders were used to prepare mixtures with the compositions of 2ZnO+SiO2+ X mol% MnO2 ( X =MnO2/2ZnO, abbreviated as Zn2SiO4- X -MnO2), where 2≤ X ≤5. The mixed Zn2SiO4- X -MnO2 mixtures were calcined from 900 to 1300°C in air in order to synthesize Zn2SiO4:Mn2+ green phosphors. The X-ray diffraction patterns of Zn2SiO4- X -MnO2 particles indicated that ZnO was present in the 900°C-calcined Zn2SiO4- X -MnO2 phosphors, but not in particles calcined at temperatures of 1000°C and higher. However, the unapparent secondary phase of ZnMnO3 was found in the 1200 and 1300°C-calcined Zn2SiO4-5-MnO2 compositions. The luminescent characteristics of Zn2SiO4- X -Mn2+ phosphors were compared with that of a commercial product (Nichia Corp., Japan). The photoluminescence (PL) intensity of 1200°C-calcined Zn2SiO4-4-MnO2 phosphors was higher and the decay times of all synthesized Zn2SiO4- X -MnO2 phosphors were longer than those of the commercial product. [Copyright &y& Elsevier]