Subject Index

Abstract

The gas sensors based on tin dioxide (SnO2) thin films and doped with different amount of palladium (Pd) were synthesized by a new developed preparation system using the pulsed Nd:YAG (532 nm) laser deposition method combined with d.c. sputtering. The Pd-doped SnO2 (SnO2–Pd) thin films have been grown on Si (1 0 0) and alumina (Al2O3) substrates using SnO2 targets. The composition ratio and the bonding states of SnO2–Pd thin films were characterized by an X-ray photoelectron spectroscopy. Surface morphology and structure of the films have been obtained by atomic force microscope and glancing-angle X-ray diffraction measurement. The effects of the sputtering discharge power of Pd on the properties of the SnO2–Pd thin films are discussed. The gas sensing properties of SnO2–Pd thin films prepared by this new pulsed laser deposition (PLD) method are also investigated over the temperature range 200–600 °C, using 0.31 vol.%H2 as a test gas. Experimental results suggest that SnO2–Pd thin films can be prepared using this new PLD method. Atomic concentration ratio of Pd in the SnO2–Pd film depends on the sputtering discharge power of Pd and varies from 1 to 6%. The maximum sensitivity of SnO2–Pd thin film gas sensor synthesized by this new PLD method is approximately 3 times higher than that of pure SnO2 thin film gas sensor grown by the conventional PLD method.