Structural and Photoluminescence Studies of (Cu, Al) Co-doped ZnO Nanoparticles

Abstract

International audiencePristine and co-doped ZnO with doping of Cu and Al nano particles have been successfully synthesized by chemical co-precipitation method without using any capping agent and annealed in air ambient at 500 0 C for one hour. Here, the Al concentration is fixed at 5 mol percent and copper concentration is increasing from 1 to 5 mol percent. The Crystallanity, structure and crystallite size of pure and co-doped ZnO nano particles are determined by X-ray diffraction (XRD) in range from 20 0 to 80 0. XRD pattern reveals that the samples possess hexagonal wurtzite structure of ZnO and the estimated particle size of pure and co-doped ZnO nano particles is 20-22nm. Morphological and compositional analysis is done by SEM and EDS. Photoluminescence studies reveals the origin of PL emission in the visible region. PL spectrum shows the blue emission peaks appeared at 435, 448 and 468 nm and green emission peak at 536 nm. Introduction. ZnO is a promising (II-V) semi conductor with wide direct band gap (3.32 eV) and large binding energy (60 MeV). It have attracted a lot of attention due to its significant properties such as room temperature luminescence, good transparency and high electron mobility. Also, it has practical applications in various fields such as solar cells, light emitting diodes, gas sensors, etc. Preferentially ZnO is in the hexagonal wurtzite structure[1-3]. Electronic structure, optical and electrical properties of the host lattice ZnO can be varied by adding of different type of metal ions such as Ca, Al, Mg, Ni and Fe[4-10]. The magnetic properties of ZnO also tuned by doping of metal ions such as Co, N, Ru and Cu[11-13]. There are different methods for the synthesis of ZnO nano particles such as solution combustion method [14], vapor phase oxidation[15], chemical vapor deposition, sol-gel[16], chemical co-precipitation method[17-19]. Among these methods chemical co-precipitation method is used for the preparation of large quantity of pure and doped ZnO nano particles because it is simple, cost effective and high yield rate. The structural, compositional and optical properties of the synthesized nano particles are presented