Local microstructure and photoluminescence of Er-doped 12CaO-7Al2O3 powder

• Published in: Journal of rare earths Vol. 26; no. 3; pp. 433 - 438
• Main Author: 王丹 刘玉学 徐长山 刘益春 王国瑞 李兴华
• Format: Journal Article
• Language: English
• Published: Jilin Teachers' Institute of Engineering and Technology, Changchun 130052, China%Center for Advanced Opto-Electronic Functional Materials Research, Northeast Normal University, Changchun 130024, China 01.06.2008; Center for Advanced Opto-Electronic Functional Materials Research, Northeast Normal University, Changchun 130024, China
• Subjects: C12A7：Er; 光线吸收; 光致发光; photoluminescence; absorption; C12A7:Er; sol-gel; raman; rare earths
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/s1002-0721(08)60112-x

Er-doped 12Ca0.7Al2O3 （C12A7：Er） powders were prepared using the sol-gel method followed by annealing inorganic precursors. X-ray diffraction （XRD）, Raman and absorption spectra revealed that Er ions existed and substituted Ca^2＋ lattice site in C12A7. The photoluminescence of C12A7：Er at room temperature was observed in the visible and infrared region using 488 nm （2.54 eV） Ar^＋ line as excitation source, respectively. The sharp and intense green emission bands with multi-peaks around 520 nm and 550 nm correspond to the transitions from the excited states ^2H11/2 and ^4S3/2 tO the ground state ^4I15/2, respectively. Furthermore, red emission band around 650 nm was also observed. It was attributed to the electronic transition from excited states ^4F9/2 to the ground state ^4I15/2 inside 4f-shell of Er^3＋ ions. The intensive infrared emission at 1.54 μm was attributed to the transition from the fast excited states of ^4I13/2 to the ground state （^4I15/2）. The temperature dependent photoluminescence of infrared emission showed that the integrated intensity reached a maximum value at near room temperature. The forbidden transitions of intra-4f shell electrons in free Er^3＋ ions were allowed in C12A7 owing to lack of the inversion symmetry in the Er^3＋ position in C12A7 crystal field. Our results suggested that C12A7：Er was a candidate for applications in Er-doped laser materials, and full color display.