An efficient luminescent bonding-type Eu-containing copolymer as a red-emitting phosphor for fabrication of LED

A luminescent europium-containing copolymer, poly(MMA-MA-co-Eu(TTA)2phen), was synthesized though a reaction of EuCl3, 1,10-phenanthroline (phen), α-thenoyltrifluoroacetone (TTA) with copolymer of maleic acid (MA) and methyl methacrylate (MMA). The copolymer was characterized by FT-IR, UV–vis, gel permeation chromatograph (GPC), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) analysis. The Eu-copolymer phosphor exhibited high thermal stability and excellent photoluminescence properties, appropriate CIE chromaticity coordinates for red and a quantum yield of 24% under near-UV light excitation. It emitted intense red light at 613 nm under UV excitation at room temperature, which is attributed to the 5D0 → 7F2 transition of Eu(III) ions. An intense red-emitting light-emitting diode (LED) was fabricated by combining poly(MA-MMA-co-Eu(TTA)2phen) with a 395 nm-emitting InGaN chip. The results indicate that the Eu-copolymer phosphor may act as a red component for fabrication of white LEDs.