Effect of temperature and pH on structural, optical and electrical properties of Ni doped ZnSe nanoparticles

Ni doped ZnSe precipitated particles were prepared using three different pH precursor solutions (8, 9 and 10) and two different solution temperatures (303 K and 363 K) by wet chemical precipitation technique. The SEM analysis reveals that the size of the particles is in the order of 5 nm at 303 K and it becomes 20 nm at 363 K. The XRD studies show that the prepared nanoparticles of Ni:ZnSe switch from cubic zinc blende to hexagonal wuzurite structure as the temperature increase from 303 K to 363 K. The UV–vis spectra of Ni:ZnSe nanoparticles show that there is no change in optical band gap with increase in pH value at 303 K but the gap increases slightly at 363 K. Linear incremental and non linear decremental natured band edge absorptions were identified for the nanoparticles prepared at different conditions of pH and temperature. The weak interaction between Se2- and Zn2+/Ni2+ and the property of superficially adhered functional groups were confirmed from the analysis of FT-IR absorption spectra. The conductivity and dielectric studies confirm that the material can be used in high frequency applications.