Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/...Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/2,is obviously altered with different silicon/aluminum ratios.The Judd-Ofelt parameters of the Er3+ ions are adopted to explain the intensity change in the NIR fluorescence,and the Raman scattering intensity versus the amount of Al and/or Si components are discussed.The spectra of the three samples are quite similar in the peak positions,but different in intensity.The maximal phonon density of state for the samples is calculated from the Raman spectra and is correlated to the NIR luminescence efficiency.展开更多
The free-standing diamond films are deposited on molybdenum substrate by direct current jet chemical vapor deposition (DCJCVD). X-ray diffraction,Raman spectroscopy and cathodoluminescence (CL) measurement are used to...The free-standing diamond films are deposited on molybdenum substrate by direct current jet chemical vapor deposition (DCJCVD). X-ray diffraction,Raman spectroscopy and cathodoluminescence (CL) measurement are used to investigate the films structure and defects related to electron transition properties of the diamond films. The X-ray diffraction spectrum reveals that the diamond films have the polycrystalline cubic structure with diffraction peaks at 43.88o and 75.24o. A sharp peak at 1331.8 cm-1 and a broad band at about 1250-1550 cm-1 from Raman spectrum are attributed to diamond phase and sp2-type carbons,respectively. Two emission peaks at 440 nm and 530 nm,associated with dislocation defects and nitrogen and vacancy complexes respectively,are observed in cathodoluminescence spectrum. In addition,in order to understand both emission processes,a simple energy level scheme is suggested.展开更多
基金Project supported by the Natural Science Foundation of Tianjin (Grant Nos. 09JCYBJC01400 and 11JCYBJC00300)the Natural Science Foundation of the Tianjin Education Committee (Grant No. 20071207)Tianjin Key Subject for Materials Physics and Chemistry
文摘Er3+-doped 25BaO-(25-x)SiO2-xAl2O3-25B2O3 transparent glasses are prepared with x = 0,12.5 and 25 by a solid-state reaction.The Er-related NIR luminescence intensity,which corresponds to the transition of 4I15/2-4I13/2,is obviously altered with different silicon/aluminum ratios.The Judd-Ofelt parameters of the Er3+ ions are adopted to explain the intensity change in the NIR fluorescence,and the Raman scattering intensity versus the amount of Al and/or Si components are discussed.The spectra of the three samples are quite similar in the peak positions,but different in intensity.The maximal phonon density of state for the samples is calculated from the Raman spectra and is correlated to the NIR luminescence efficiency.
基金supported by the Natural Science Foundation of Tianjin (No. 06YFJZJC00100)
文摘The free-standing diamond films are deposited on molybdenum substrate by direct current jet chemical vapor deposition (DCJCVD). X-ray diffraction,Raman spectroscopy and cathodoluminescence (CL) measurement are used to investigate the films structure and defects related to electron transition properties of the diamond films. The X-ray diffraction spectrum reveals that the diamond films have the polycrystalline cubic structure with diffraction peaks at 43.88o and 75.24o. A sharp peak at 1331.8 cm-1 and a broad band at about 1250-1550 cm-1 from Raman spectrum are attributed to diamond phase and sp2-type carbons,respectively. Two emission peaks at 440 nm and 530 nm,associated with dislocation defects and nitrogen and vacancy complexes respectively,are observed in cathodoluminescence spectrum. In addition,in order to understand both emission processes,a simple energy level scheme is suggested.
