Abstract
In the present work PS/polyaniline heterojunction structures were fabricated and its application for ammonia sensing was explored by measuring its I-V characteristics. Surface morphology of PS has been investigated using Scanning Electron Microscopy (SEM) and the chemical properties of polyaniline were studied using Fourier Transform Infra Red (FTIR) spectroscopy. I-V characteristics of the heterojunction were measured at 0.5 ppm and 2.5 ppm of ammonia. Dynamic variation of resistance of the device was also measured at 0.5ppm of ammonia. A comparison was also made by making Si/polyaniline heterojunction of the same dimension to study the effect of porous Si on the I-V characteristics of both the devices in the presence of ammonia vapour. It was observed that PS/Polyaniline is more sensitive than the Si/polyaniline heterojunction.