X-ray absorption spectroscopic studies of Eu-doped ZnO nanowires

• Main Authors: Wei-Lun Huang, 黃偉倫
• Other Authors: Way-Faung Pong
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/69926984999073466142

碩士 === 淡江大學 === 物理學系碩士班 === 97 === X-ray absorption near-edge structure (XANES), extended x-ray absorption fine structure (EXAFS), and Scanning photoemission microscope (SPEM) measurements were used to observe the influence of Eu-doped zinc oxide (ZnO) nanowires and to understand the unoccupied as well as occupied states of electronic structure and locally fine structure. The O K-edge XANES spectrum showed a broad and lower intensity compared to the undoped sample, which is interpreted as a rehybridization of the O2p derived state with the Eu5d state. This process lowers the energy of O2p states and enhances its occupancy by electrons from europium. EXAFS have revealed that Eu3+ ions maybe replaced Zn2+ in the Zn site, or filled-in in the Zn-site vacancies, but did not change the Wurtzite structure of host materials. The process thereby increases defects in the surface resulting to the enhanced PL of the Eu-doped ZnO nanowires.