Fig. 1From: Enhance the Er3+ Upconversion Luminescence by Constructing NaGdF4:Er3+@NaGdF4:Er3+ Active-Core/Active-Shell Nanocrystals a–c TEM micrographic images and d–f size distribution of the NaGdF4:12%Er3+ core NPs, NaGdF4:12%Er3+@NaGdF4 active-core/inert-shell NPs and NaGdF4:12%Er3+@NaGdF4:10%Er3+ active-core/active-shell NPs, respectivelyBack to article page