Ln3+-Induced Diblock Copolymeric Aggregates for Fully Flexible Tunable White-Light Materials.

Xinzhi Wang,Jianguo Tang,Laurence Belfiore,Yao Wang,Wei Wang,Xinbo Zhang,Guanghui Wang,Wei Ding,Wenfei Shen,Junjie Ren,Linjun Huang

doi:10.3390/nano9030363

Abstract

In this research contribution, nano-aggregates have been fabricated by introducing lanthanide (Ln3+) ions into solutions of amphiphilic diblock copolymers of polystyrene-b-poly (acrylic acid) (PS-b-PAA). The coordination of acrylic acid segments to lanthanide cations induces diblock copolymer (BCPs) self-assembly in order to design stable white luminescent hybrid nanoparticles with fine uniform particle size. The introduction of Ln3+ ions (Eu3+ and Tb3+) bestows the micelles, precisely white light, upon excitation of 342 nm. Lanthanide coordination cross-linking of poly (acrylic acid) segments, or blocks, endows the micelles higher thermal stability than that of BCPs micelles without cross-linking. As the most important key point of this work, the regular and stable nano-particles with high emission quality can make fully flexible electroluminescent devices with self-formation or uncoordinated into polymer hosts. Instead of inorganic luminescent nanoparticles with hard cores, this method can potentially apply for fully flexible white-light emitting diodes (FFWLEDs).

Highlights

Polymer-based light emission materials has gained hugely increased attention in recent years because of their flexible property to meet roll-up/spread applications, such as full color displays and photoelectronic devices [1,2,3,4]
The absorption band for BCPs ranges from 260 nm to 340 nm and the maximum absorption is at 268 nm, which is primarily attributed to the effect of the π-π* transition of benzene ring of PS-b-PAA [30]
We have synthesized the novel and flexible fluorescent polymeric micelles (BCPs-Ln3+-Phen) from Eu3+ and Tb3+ ions coordinated amphiphilic diblock copolymers (PS-b-PAA) which can be used as excellent flexible materials

Summary

Introduction

Polymer-based light emission materials has gained hugely increased attention in recent years because of their flexible property to meet roll-up/spread applications, such as full color displays and photoelectronic devices [1,2,3,4]. White light generation depends on the color mixing principles of trichromatic (red, green, and blue) or dichromatic (yellow, blue) lights [7,8,9], there are two characteristic modes to fabricate white-light-emitting materials in the literature. The first is blue light as a light resource to excite yellow phosphors, which is widely used due to the technique’s simplicity and low cost. The commendably realized white LED, YAG: Ce, is used as yellow phosphor. It has many limitations, such as low luminous efficiency and color-rendering index [10]. The second is UV-light excited phosphors to emit red, green, and blue light, which can solve the above limitations and can improve the stability of light color. The scientific target is to find stable, narrow-emitting and highly luminous, efficient materials [11,12]

Methods

Results

Conclusion