Studies of Physical Properties of Nano-crystalline Nickel Sulphide Thin Films Grown by Simple Chemical Routea??

摘要

Nanocrystalline Nickel Sulphide thin films were prepared using chemical bath deposition method on glass substrate. Nickel Sulphate and thiourea were used as starting chemicals. Triethanolamine (TEA) and ammonia was used as the complexing agents. In order to obtain good quality thin films preparative parameters such as concentration, temperature, deposition time, pH of solution have been optimized. Films were characterized using X-ray diffraction for crystallographic analysis. The films were shown to be nanocrystalline in nature with good uniformity. From scanning electron micrographs, the surface appeared to be comparatively granular with irregularly shaped grains. Optical properties of the films were determined from analysis of the measured absorption spectrum. The Nickel Sulphide thin films exhibited direct band gap transition with band gap energy ~2.8 eV. The films were observed to have thickness value range from 300 nm to 500 nm. Electrical properties of Nickel Sulphide film determine using two point probe method. The films are semiconducting, having room temperature resistivity of the order of ~10 Ωcm.