Influence of Mn doping on the structural, photoconductivity and electro luminescence of Strontium tartrate crystals

The silica gel growth system involves the use of strontium chloride as the supernatant solution and sodium meta silicate impregnated with tartaric acid as lower reactant, results in the crystallization of the Strontium tartrate. The material was characterized by using Powder XRD and TGA. In the present study, we report the change in structural and electro-optical properties of the grown crystal on Mn doping and found that they are very much influenced by the presence of defects in the original crystal lattice. The imperfection in the crystal lattice sometimes acts as traps or as recombination centers. Luminescent centers form at the cracks, voids, dislocations and stacking faults. These defects provide sites for the precipitation of the excess carriers if it is produced. The change in photoconductivity (PC) of the material as a function of time, intensity of irradiation light, annealing temperature, applied voltage and concentration of the dopant (Mn) was investigated. AC/DC Electro luminescence (EL) of Strontium tartrate crystals was measured with the help of a Photo multiplier tube (PMT) and its EL brightness was measured as a function of voltage of excitation at different annealing temperature and concentration of Mn