We have synthesized luminescent YVO 4 : Yb, Er nanoparticles (NPs) in the size range of 10–700 nm. A bright green luminescence of the dry NPs powder due to Er 3+ ions emission centered at 526 and 550 nm was compared for upconverting and downconverting laser excitations at 980 nm and 257 nm, respectively. Moreover, the NPs exhibited bright luminescence in colloidal water solution upon 980 nm laser irradiation. All experiments showed very weak radiative 4 F 9/2 → 4 I 15/2 emission from Er 3+ ions at 660 nm that indirectly indicates low efficiency of multiphonon intraionic transitions and insensitivity of the NPs to the luminescence quenchers in the water solution. A broad red band in the luminescence spectrum appearing under intense 257 nm laser excitation can be attributed to emission from crystal lattice defects in the NPs. Based on these facts we propose that YVO 4 : Yb, Er NPs are promising as efficien...

中文翻译：

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用于生物应用的光转换Yb 3+ / Er 3+掺杂YVO 4纳米粒子

我们已经合成了尺寸在10-700 nm之间的发光YVO 4：Yb，Er纳米颗粒（NPs）。比较了分别以526和550 nm为中心的Er 3+离子发射引起的干燥NPs粉末的亮绿色发光分别用于980 nm和257 nm的上转换和下转换激光激发。此外，在980 nm激光照射下，NPs在胶体水溶液中显示出明亮的发光。所有实验均表明，Er 3+离子在660 nm处的辐射4 F 9/2→4 I 15/2发射非常弱，这间接表明多声子离子内跃迁效率低，并且NP对水溶液中的发光猝灭剂不敏感。在强257 nm激光激发下出现的发光光谱中的宽红带可归因于NP中晶格缺陷的发射。