LaF3: Pr3+ hollow hexagon nanostructures via green and eco-friendly synthesis and their photoluminescence properties

LaF 3 nanocrystals (NCs) are usually used as good host matrix for down-conversion phosphors owing to their impressive photophysical properties. In this study, Pr 3+ -activated LaF 3 with hollow hexagon nanostructures (HHNs) is achieved by a green and eco-friendly hydrothermal method without any catalyst, template, or surfactant. The pore structure of the LaF 3 HHNs is greatly affected by the content of Pr 3+ ions and hydrothermal reaction time. The LaF 3 : Pr 3+ NCs excited by 467 nm light show strong emission peaks locating in visible light region (centered at 612 and 635 nm) and the first biological window region (existed in 689 and 721 nm), respectively. The relative photoluminescence (PL) intensity of LaF 3 : Pr 3+ NCs from 20 to 60 °C (biological temperature) decreases slightly and decreases only 20% at 120 °C. The PL emission intensity could reach the maximal value with doping ~ 1.5% Pr 3+ ions. Based on the outstanding photophysical properties, LaF 3 : Pr 3+ NCs will be used for both warm white light-emitting diodes and bio-imaging.