Functional properties of donor (Al)- and acceptor (Cu)- codoped high dielectric constant zinc oxide nanoparticles

Abstract

In present work, research has been conducted on pristine, Copper (Cu1+ as acceptor) and Aluminium (Al3+ as the donor) co-doped Zinc Oxide1 nanoparticles synthesized with doping concentration 1%M, 0.75%M, 0.5%M, and 0.25%M annealed at 350°C and 600°C each through co-precipitation method. The measurements of XRD, SEM and UV-Vis DRS analysis confirmed the substitution of Cu and Al ions into ZnO lattice sites. Luminescent emission of Al-Cu co-doped ZnO gets modified with changed electronic recombination due to the existence of oxygen vacancies and such other defects and also decreases the bandgap. These samples were also characterized through Impedance Spectroscopy for analysing the electrical behavior of the samples. The values of the real part of the dielectric and tangent loss were seen to be decreasing with an increase in frequency while ac-conductivity was increased for all the samples at higher frequencies. The appearance of Semi-circular arcs in the impedance and modulus plots confirmed the contribution of grains and grain boundaries and also the presence of different relaxation processes for our samples.