Tunable white light emission of a large area film-forming macromolecular complex with a high color rendering index

Abstract

The technological route of pre-polymerization and post-coordination was employed to obtain a rapid film-forming macromolecular complex emitting white light by simultaneously combining poly (styrene-co-glycidyl methacrylate) with three primary color complexes [r(R)/g(G)/b(B)]. The white light emission of the macromolecular complex was realized by tuning the ratios of the trichromatic complexes or altering excitation wavelengths. Upon excitation at 365 nm, macromolecular complex 5 with R:G:B = 1:10:1 exhibits three discrete characteristic peaks at 458 (blue emission), 543 (green emission), and 612 (red emission) nm. The corresponding CIE coordinates of (0.332, 0.337) are in close proximity to pure white light (0.330, 0.330). Macromolecular complex 3 (R:G:B = 1:8:0.5) achieves white emission being excited at the wavelength of 375 nm. Macromolecular complex 5 was melted at 140 °C, dropped on a 365 nm UV chip, and then cooled to room temperature to fabricate an LED device with CIE coordinates of (0.35, 0.34), CCT of 5306 K, and CRI of 95.2. The prepared macromolecular complex film further shows vivid color reproduction for real objects, confirming the high rendering index of the macromolecular complex. In addition, the macromolecular complex remains stable up to 272.6 °C, meeting the requirements of operating temperature for LEDs. This work establishes a rapid film-forming macromolecular complex with potential application in NUV-WLEDs.