Fig. 2From: Enhance the Er3+ Upconversion Luminescence by Constructing NaGdF4:Er3+@NaGdF4:Er3+ Active-Core/Active-Shell NanocrystalsXRD patterns of the a NaGdF4:12%Er3+ core nanoparticles, b NaGdF4:12%Er3+@NaGdF4 active-core/inert-shell nanoparticles and NaGdF4:12%Er3+@NaGdF4:10%Er3+ active-core/active-shell nanoparticles (C@x% for short). The bottom bars represent the standard α-NaGdF4 (JCPDS 27–0697) and β − NaGdF4 crystal data (JCPDS 27–0699), respectively.Back to article page