Fabrication of n-CdTe/p-polyaniline heterojunction-based room temperature LPG sensor

The response of a heterojunction formed with n-CdTe and p-polyaniline to liquefied petroleum gas (LPG) has been investigated using forward bias current measurement at room temperature. The CdTe and polyaniline films were deposited using electrodeposition technique. The thickness of CdTe and polyaniline was optimized in order to get a junction ideality factor close to unity. The n-CdTe/p-polyaniline junction fabricated under optimized conditions exhibited rectifying current–voltage (I–V) characteristics with a rectification ratio of 7 × 103 and a junction ideality factor of 1.28. The junction was found to be sensitive to LPG at an operating temperature of 300 K. The LPG response was tested through the shift in forward biased I–V curves at different concentrations of LPG. Maximum response up to 67.7% was observed for 0.14 vol% of LPG.