Preparation and Characterization of Lanthanum Gallium Silicate Thin Films

• Main Authors: Feng-Wei Wang, 王逢偉
• Other Authors: Yi Hu
• Format: Others
• Language: en_US
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/4t5zs8

博士 === 大同大學 === 材料工程學系(所) === 95 === La3Ga5SiO14 (LGS) has high potential in applications as a new non-ferroelectric, piezoelectric material with high electromechanical coupling factor and almost zero temperature coefficient of delay (TCD). In this study, LGS thin films are prepared by RF sputtering technique on SiO2/Si (111) substrate and MgO buffer layer/Si(100) with stoichiometric LGS polycrystalline targets and sol-gel method with LGS precursors. The as-deposited films are amorphous and crystallization of the films is conducted by annealing. Crystalline LGS thin films on Si substrate with trigonal structure were obtained after annealing at temperature higher than 1200℃ in air. However, the as-deposited films on MgO buffer layers were commenced to crystallization under post-annealing at temperatures higher than 1100�aC for 5hrs in air. These thin films show blue emission from the photoluminescence (PL) investigation. The emission peak of the films was found to be 429 nm under the excited light of �鈃x=381nm. The PL emission of the films is attributed to the formation of oxygen vacancies as examined by the X-ray photoelectron spectroscopy (XPS).