Enhanced luminescence through interface energy transfer in hierarchical heterogeneous nanocomposites and application in white LEDs

J Colloid Interface Sci. 2021 Feb 1:583:204-213. doi: 10.1016/j.jcis.2020.09.049. Epub 2020 Sep 23.

Abstract

Highly efficient light-emitting materials are essential for achieving high-performance devices. Here, a novel composite system, as well as enhanced luminescence processes, was designed, where NaLn(MoO4)2 ultra-small nucleus can be effectively isolated by In(OH)3 to form NaLn(MoO4)2@In(OH)3 composite nanoclusters due to the different nucleation rate between NaLn(MoO4)2 and In(OH)3, and then these small composite clusters gradually self-assemble into hierarchical structures. As we expected, the enhanced luminescence was achieved from hierarchical NaLn(MoO4)2 nanostructures with adjusting the distance among NaLn(MoO4)2 ultra-small nucleus by inserting In(OH)3. A series of spectroscopy results show that the In(OH)3 not only acts as an energy transfer bridge from CTB Eu3+ → O2- (or MoO42- absorption) to Eu3+, but also can effectively alleviate the concentration quenching of Ln3+ and change the J-O parameters. The Raman peak at 134 cm-1 is helpful to populate the 5D0 level of Eu3+ or the excited states of Er3+, resulting in stronger up/down-conversion emissions. The use of NaLn(MoO4)2@In(OH)3 in white light-emitting diodes (LEDs) has been demonstrated. The combination of red emission from NaLn(MoO4)2@In(OH)3 with blue, green, and yellow emission from halide perovskites could achieve white light with excellent vision performance (an LER of 376 lm/W) and superior color quality (CRI > 92). The findings of this experiment provide a new idea for the design of composite interface materials.

Keywords: Lanthanide; Luminous enhancement; NaLn(MoO(4))(2)@In(OH)(3); white LEDs.