Effect of the Deposition Temperature on Ammonia Gas Sensing Based on SnO2/Porous Silicon

Enhancing the performance of the room temperature gas sensing that based on a wide surface area of the metal oxide semiconductor is the most important field. In this paper, tin dioxide has been successfully prepared and deposited on the photoelectrochemical etched n-type silicon substrate by spray pyrolysis technique at different deposition temperatures. The constructional, morphological, and topographical properties have been inspected. The XRD patterns showed a broadening peak with a preferential one in the direction (110) having a tiny crystalline size and a huge surface area. The SEM and atomic force microscope displayed semi-spherical microstructures and nanostructures aggregated on the wall of the pores, and the others cover some pores; also, the surface was very rough and has small grains. Sensing characteristics depicted an ultra-response toward ammonia gas at the room temperature with the value of (175%) and quick response and recovery times at the deposition temperature of 350 degrees C. The porous silicon substrate was the ideal way for SnO2 nanoparticles to increase the gas response toward ammonia gas molecules in the humid air.