Highly Sensitive H(2)S Sensor Based on the Metal-Catalyzed SnO(2) Nanocolumns Fabricated by Glancing Angle Deposition

As highly sensitive H(2)S gas sensors, Au- and Ag-catalyzed SnO(2) thin films with morphology-controlled nanostructures were fabricated by using e-beam evaporation in combination with the glancing angle deposition (GAD) technique. After annealing at 500 °C for 40 h, the sensors showed a polycrystalline phase with a porous, tilted columnar nanostructure. The gas sensitivities (S = R(gas)/R(air)) of Au and Ag-catalyzed SnO(2) sensors fabricated by the GAD process were 0.009 and 0.015, respectively, under 5 ppm H(2)S at 300 °C, and the 90% response time was approximately 5 s. These sensors showed excellent sensitivities compared with the SnO(2) thin film sensors that were deposited normally (glancing angle = 0°, S = 0.48).