p-PEDOT:PSS as a heterojunction partner with n-ZnO for detection of LPG at room temperature

Investigation towards the performance of room temperature (27 °C) liquefied petroleum gas (LPG) sensor based on the heterojunction between p-PEDOT:PSS and n-type ZnO is reported. The junction was developed by using chemically deposited ZnO film on to fluorine doped tin oxide (FTO) coated glass substrate followed by coating of thin slurry layer of PEDOT:PSS by using spin coating technique. Both these methods are simple, inexpensive and suitable for large area applications. Different characterization techniques were used to characterize structural, surface morphological and compositional of the material deposited. LPG sensing behavior of the heterojunction was studied at room temperature along with the stability studies. At room temperature, the heterojunction showed 58.8% sensitivity upon exposure to 1000 ppm of LPG with good response and recovery time like 225 s and 190 s, respectively. Furthermore, the LPG sensor reported is cost-effective, user friendly, and easy to fabricate using low cost chemical methods at room temperature.

► Formation of heterojunction n-ZnO and p-PEDOT:PSS at room temperature (27 °C).
► Use of this heterojunction as room temperature LPG sensor.
► Remarkable gas response with good stability of the sensing device.
► Use of heterojunction could offer cost-effective LPG sensor that is ecological-friendly.
► The mass production using scalable room temperature chemical deposition process.