Cu2+ Doped PVA-Capped CdSe Polymer Applications to Blue LED

Cu2+ doped CdSe polymer was prepared by using poly vinyl alcohol (PVA) at room temperature. The prepared sample was characterized by Powder X-ray diffraction, optical absorption, Photoluminescence, EPR and FT-IR studies. X-ray diffraction pattern showed the cubic zinc blende crystalline phase of CdSe and the average size of the grains is in the order of 23 nm. Optical absorption spectrum exhibited a broad band at 832 nm which is the characteristic of Cu2+ in distorted octahedral symmetry. EPR results indicate that Cu2+ ion enters the host lattice as tetragonally elongated octahedral site. By correlating optical and EPR data, the evaluated bonding parameters suggested that the bonding between the doped ion and ligands is partially covalent. Luminescence spectrum gives the emission bands in UV and blue region. The calculated CIE chromaticity coordinates from emission spectrum are located in blue region. FT-IR spectrum exhibits the molecular vibrations of PVA in CdSe.