LPG SENSING PROPERTY OF NICKEL DOPED CdS THIN FILM SYNTHESISED BY SILAR METHOD

Abstract

ABSTRACT Pure and Ni doped CdS thin films are synthesised by low-cost successive ion layer adsorption and reaction (SILAR) method. Characterisation of the samples are done using XRD, EDAX, TEM, SEM, etc. EDAX confirms presence of Ni in CdS thin films. The particle size estimated from TEM image is about 22–28 nm. SEM images shows porosity increases with nickel doping. Increase of urbach energy with Ni doping suggests increase in disorder in the film. Semiconducting metal oxides (SMO) normally used in gas sensors requires very high operating temperatures for sensing gases. So, metal sulphide thin films can substitute them as it has potential to be new age low temperature gas sensing material. Nickel incorporation in CdS shows enhancement in sensitivity and a significantly high sensitivity of ~55% was observed at a reasonably low temperature of 120°C in presence of 300 ppm LPG.