PbS/p-Si NW Heterojunction Thin Film Device for Room Temperature NH₃ Detection

One dimensional heterostructures with a definite interface where the host particle is decorated with the secondary material have been widely exploited for photocatalysis because of increased efficiency. Herein we report the synthesis of PbS−Si NW heterojunction using low temperature chemical bath deposition (CBD) techniques. Temperature, time, and the complexing agents of the growth solution were optimized to control the morphology and the resultant properties of the heterojunction thin films. These synthesized thin films exhibit high sensor responses in the presence of ammonia (NH₃) due to an increase in the surface area and efficient p-n junction formation. Additionally, there is a vast improvement in the detection limit of the sensors as our device was found to respond at concentrations as low as 0.1 ppm. Growth conditions are found to have significant influence on the sensor response.