Cool White Light Emission in Dysprosium and Salicylic Acid Doped Poly Vinyl Alcohol Film Under UV Excitation

Dysprosium (Dy) and Salicylic acid (Sal) doped Poly Vinyl Alcohol (PVA) films have been successfully prepared by solution cast technique. The absorption, excitation, emission and lifetime analysis of the samples have been carried out. Judd-Ofelt theory has been used to estimate several parameters for DyCl3 and Dy(Sal)(3)Phen in PVA polymer film which show fair agreement between the experimental and the theoretical values supporting the J-O theory. A combination of blue and yellow emissions in Dy-x(Sal)(3)Phen co-doped PVA samples makes one perceive cool white light when excited by ultraviolet light. Energy transfer (ET) from Sal to Dy3+ is investigated by directly observing the luminescence intensity of Dy3+ in the Dyx(Sal)(3)Phen co-doped PVA samples which is much stronger than that in the DyCl3 in PVA which is further confirmed by lifetime studies with different concentrations of Dysprosium ion (Dy3+). The generation of white light with chromaticity coordinates (0.30, 0.34) makes it potential material for white LED and display devices.