离子共掺杂对BaTiO_3:Er上转换发光性能的影响

Influence of Ions Co-Doping at Different Site upon Upconversion Luminescence Properties of BaTiO_3:Er System

采用高温固相反应法,调控Ba/Ti比制备了Er^(3+)替代BaTiO_3不同晶格位置的粉体。结果表明,Er^(3+)掺杂不同的格位将会导致晶体结构对称性及发光强度发生明显的变化。根据电荷补偿原理分别在Ba位和Ti位共掺Li+和Nb^(5+),并研究了其对晶体结构、形貌和上转换发光性能的影响。采用Er^(3+),Li+以及Er^(3+),Nb^(5+)共掺后,粉体的上转换发光强度均得到显著的提高。值得注意的是Er^(3+),Li+共掺Ba位样品较Er^(3+),Nb^(5+)共掺Ti位样品强度提高得更明显,表明二者强度的增强分别归因于不同的机制。其中Er^(3+),Nb^(5+)共掺样品强度的提高主要归因于电荷补偿原理,而Er^(3+),Li+共掺则是由晶体场对称性的降低和电荷的补偿共同作用的结果。

Er^3＋doped BaTiO3 powders co-doped with inequivalent ions at different sites were fabricated by solid-state reaction method. The upconversion luminescence properties were improved by using two methods based on charge compensation mechanism,including Er^3＋/Li＋co-doping at A-site and Er^3＋/Nb^5＋co-doping at B-site. The correlation between crystal structure and luminescence property reveals that there exist different luminescence mechanisms contributing to such enhancement. Compared to the Er^3＋/Nb^5＋doped sample,a more distinct enhancement in photoluminescence intensity was detected for Er^3＋/Li^＋co-doped sample,which was mainly ascribed to the charge balance and the decrease of structure symmetry.