Tunable white light emission of Eu,Tb,Zn-containing copolymers by RAFT polymerization

Abstract

In this work, a novel copolymer PS–Eu–Tb–Zn, which can match a 365 nm UV chip, was synthesized by the RAFT polymerization of Tb(p-BBA)₃UA, Eu(TTA)₂(Phen)MAA, Zn(BTZ)UA and styrene. TG-DTG and PL analyses indicate that the copolymer PS–Eu–Tb–Zn displays favorable thermal stability and luminescence properties. When excited at 365 nm, the copolymer exhibits emission peaks at 421 nm (blue emission), 488, 543 nm (green emission), 589 and 615 nm (red emission). The white light of the copolymer can be obtained by tuning the ratios of the three complexes and excitation wavelengths. The CIE coordinates (0.352, 0.330) of the copolymer are optimal upon excitation at 365 nm. For the fabricated white LED using a 365 nm UV chip with the copolymer, the CCT is 5684 K, and the CRI is 83.1. All the results indicate that the copolymer can be applied as a phosphor for the fabrication of NUV-based white LEDs.