Influences of Al doping concentration on structural,electrical and optical properties of Zn0.95Ni0.05O powders

Nanocrystalline Zn_0.95−xNi_0.05Al_xO (x = 0.01, 0.02, 0.05 and 0.10) diluted magnetic semiconductors have been synthesized by an auto-combustion method. X-ray diffraction measurements indicate that all Al-doped Zn_0.95Ni_0.05O samples have the pure wurtzite structure. Transmission electron microscope analyses show that the as-synthesized powders are of the size 40–45 nm. High-resolution transmission electron microscope, energy dispersive spectrometer and X-ray photoemission spectroscope analyses indicate that Ni²⁺ and Al³⁺ uniformly substitute Zn²⁺ in the wurtzite structure without forming any secondary phases. The Al doping concentration dependences of cell parameters (a and c), resistance and the ratio of green emission to UV emission have the similar trends.