Light-emission in Tb3+ and Eu3+: PVP polymer films

Analysis of photoluminescence spectra of PVP and Tb3+ or Eu3+: PVP polymer films has been done. Emission spectrum of the host matrix poly (vinyl pyrrolidone) (PVP) has shown an intense blue emission at 424 nm [pi(0 ->) n(1)pi(2)]. By using a solution cast method, more clear and transparent PVP polymer films have been developed for analysis with the addition of Tb3+ and Eu3+ ions separately into PVP polymer matrix; green and red colour emitting polymer films have been developed. Also undoped PVP polymer film has been prepared as a reference film for which XRD, FTIR, Raman and TGA-DTA spectral profiles have been carried out. From the measured emission spectrum of the Tb3+: PVP polymer film, an intense green emission at 544 nm (D-5(4)-> F-7(5)) has been observed with an excitation at 311 urn. Under an UV source a bright green emission has been noticed from the surface of the Tb3+: PVP polymer film, and a bright red emission has been noticed from the surface of the Eu3+: PVP polymer film. The emission spectrum of Eu3+: PVP polymer film has also revealed an intense red emission at 612 nm (D-5(0)-> F-7(2)).