Development of polyaniline/Cu2ZnSnS4 (CZTS) thin film based heterostructure as room temperature LPG sensor

In this study, we report simple fabrication and room temperature liquefied petroleum gas (LPG) sensing performance of polyaniline/Cu2ZnSnS4 (CZTS) heterojunction. Synthesis of polyaniline/CZTS heterojunction was carried out by layer-by-layer deposition of CZTS followed by electrodeposition of polyaniline. The CZTS and polyaniline films were characterized using X-ray diffraction (XRD), FT-Raman, thermoemf and scanning electron microscopic (SEM) techniques. The CZTS thin film was found to be nanocrystalline with densely compact microstructure while polyaniline were amorphous with interconnected fuzzy nanofibrous architecture. The maximum gas response of 44% was observed at 0.06 vol% of LPG for polyaniline/CZTS heterojunction based sensor. The LPG response of heterojunction was decreased from 44 to 12% at the relative humidity of 90%. Good stability and fast response and recovery time periods of the present heterojunction suggest that the polyaniline/CZTS heterojunction is a potential candidate for room temperature LPG sensor.