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

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+ -> O-2(or MoO42 absorption) to Eu3+, but also can effectively alleviate the concentration quenching of Ln(3+) and change the J-O parameters. The Raman peak at 134 cm(-1) is helpful to populate the D-5(0) 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. (C) 2020 Elsevier Inc. All rights reserved.

Automated summary

Efficient luminescence was achieved through a novel composite system, with enhanced performances demonstrated in white light LEDs with excellent vision and superior color quality. The findings suggest a new idea for the design of composite interface materials.