NIR-Driven White Light Diode Formed with UCNP@AIEgen Nanocomposites

Abstract

Upconversion nanoparticles (UCNPs) and polymerizable molecules of aggregation-induced emission (AIE) were combined to produce white light emission. Blue and ultraviolet light-emitting doped lanthanide UCNPs (LiYF4:Yb3+/Tm3+@LiYF4:Yb3+), polymerizable red light-emitting 1,4-bis(piperidinyl-1-propenyl bromide)anthracene (1,4-BPPA), and green light-emitting 9,10-BPPA AIE molecules were mixed with photopolymerizable acrylate oligomers for photopolymerization to form a luminescent film. The fluorescence spectrum, obtained by exciting the LiYF4:Yb3+/Tm3+@LiYF4:Yb3+ UCNPs with 980 nm near-infrared light, exhibited visible light emission, and high-energy emission included ultraviolet light at 365 nm and blue light at 450 and 475 nm. The high-energy light produced through the transfer of energy from the UCNPs excited 1,4-BPPA and 9,10-BPPA molecules to emit red and green light, thus producing a hybrid of red, blue, and green light emission that resulted in white light. X-ray diffractometry, scanning electron microscopy, ultraviolet–visible spectrometry, and fluorescence spectrometry were used to analyze the materials. The CIE coordinates of the white light-emitting film were (0.3358, 0.3536), corresponding to a correlated color temperature of 5370 K. The results demonstrate that upconversion particles and polymerizable AIE molecules can be combined to fabricate a white light-emitting diode film.