Enhanced ultraviolet upconversion in YF3:Yb3+/Tm3+ nanocrystals
来源期刊：Journal of Rare Earths2009年第2期
论文作者：王国凤 秦伟平 王丽丽 尉国栋 朱培芬 张代生 丁福恒
文章页码：330 - 333
摘 要：Unusual intense infrared-to-ultraviolet upconversion luminescence was observed in YF3:Yb3+（20%）/Tm3+（1%） nanocrystals under 980 nm excitation. The intense ultraviolet emissions （1I6→3H6, 1I6→3F4, and 1D2→3H6） were affirmed arising from the excitation processes of five-photon and four-photon. In comparison with the bulk sample with the same chemical compositions, ultraviolet upconversion luminescence of the nanocrystals was markedly enhanced. Spectral analysis indicated that the enhancement was attributed to the decrease of Judd-Ofelt parameter Ω2, which precluded the transition rate from 3F2 to 3F4, enhanced the energy transfer process and populated the 1D2 level: 3F2→3H6 （Tm3+）: 3H4→1D2 （Tm3+）.
王国凤，秦伟平，王丽丽，尉国栋，朱培芬，张代生，丁福恒
摘 要：Unusual intense infrared-to-ultraviolet upconversion luminescence was observed in YF3:Yb3+（20%）/Tm3+（1%） nanocrystals under 980 nm excitation. The intense ultraviolet emissions （1I6→3H6, 1I6→3F4, and 1D2→3H6） were affirmed arising from the excitation processes of five-photon and four-photon. In comparison with the bulk sample with the same chemical compositions, ultraviolet upconversion luminescence of the nanocrystals was markedly enhanced. Spectral analysis indicated that the enhancement was attributed to the decrease of Judd-Ofelt parameter Ω2, which precluded the transition rate from 3F2 to 3F4, enhanced the energy transfer process and populated the 1D2 level: 3F2→3H6 （Tm3+）: 3H4→1D2 （Tm3+）.
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