【摘要】 采用非水性溶胶-凝胶法制备了0.1%Er³⁺（摩尔分数,下同）、0%～2%Li⁺共掺杂TiO₂粉末,在980nm半导体激光器（LD）激发下获得了中心波长526nm、550nm的绿色和663nm的红色上转换发光。Li⁺共掺杂对掺Er³⁺:TiO₂的相结构未产生影响,但极大增强了上转换发光强度。随Li⁺共掺杂摩尔分数的逐渐增大,绿色和红色上转换发光强度先增大后减小,当Li⁺摩尔分数为1%时,上转换发光强度达到最大,绿色和红色上转换发光强度分别比掺Er³⁺:TiO₂提高了约330倍、30倍和60倍。Er³⁺、Li⁺共掺杂TiO₂粉末的绿色和红色上转换发光均为双光子吸收过程。Li⁺共掺杂不改变Er³⁺的上转换发光机制,但破坏了Er³⁺的局部晶体场对称性,影响了Er³⁺内部4f能级的跃迁几率,导致上转换发光强度增强。更多还原

【Abstract】 The 0.1%Er³⁺-doped TiO₂ powders with 0%～2%Li⁺ codoping are performed by the non-aqueous sol-gel method.The green and red upconversion emissions centered at about 526nm,550nm and 663nm are detected by a 980nm semiconductor laser diode excitation.The codoping of Li⁺ has no effect on the structure of Er³⁺:TiO₂, however,strongly improves the upconversion emission intensity.With increasing the codoping concentration of Li⁺, the intersity of green and red upconversion emissions increases at first and then decreases,with highest intensity for 1%Li⁺ codoping.The intensity of green and red emission is about 330 times,30 times and 60 times greater than that of Er³⁺ -doped TiO₂ without Li⁺.The two-photon absorption upconversion process is involved in the green and red upconversion emission of Er³⁺-Li⁺ codoped TiO₂.The codoping of Li⁺ does not change the upconversion mechanism of Er³⁺,but distort the local field symmetry of the Er³⁺ and hence increases the intra-4f transitions of Er³⁺,which enhances the upconversion emission intensity of Er³⁺:TiO₂.更多还原