One‐Pot Synthesis of Homogeneous EuF 3 Nanoplates: A Near‐Ultraviolet Light‐Induced Red‐Emitting Bifunctional Platform for in vitro Cell Imaging and Solid‐State Lighting

We reported a new approach to prepare the homogenous EuF 3 nanoplates and discussed their potential applications. Upon 396 nm excitation, the EuF 3 nanoplates exhibited the visible emissions with high color purity of 84.7%. The monitored photoluminescence emission spectrum indicated that the Eu 3+ ions took the high symmetry positions in the host lattices which was further confirmed via the theoretical calculation based on the Judd‐Ofelt theory. The thermal quenching performance of the EuF 3 nanoplates was analyzed by the temperature‐dependent photoluminescence emission spectra and the activation energy was decided to be 0.28 eV. With the aid of the near‐ultraviolet chip and EuF 3 nanoplates, a red‐emitting light‐emitting diode device was prepared so as to identify the feasibility of the EuF 3 nanoplates for solid‐state lighting. Additionally, the cell viability of the EuF 3 nanoplates as well as their fluorescence imaging behaviors in the A549 lung cancer cells was also investigated. The observed results demonstrated that the EuF 3 nanoplates were bifunctional platform for in vitro cell imaging and solid‐state lighting.