Optical and electrical gas sensing properties of In/sub x/O/sub y/N/sub z/ films

In this paper we describe the optical and electrical gas sensing properties of In/sub x/O/sub y/N/sub z/ films promoted by an ultra-thin gold overlayer. We have fabricated In/sub x/O/sub y/N/sub z/ films with a nanocrystalline porous structure by RF-sputtering in Ar/N/sub 2/ followed by an annealing process. Gold particles with 20-30 nm diameter on top of the In/sub x/O/sub y/N/sub z/ films have been formed by DC-sputtering followed by an annealing process. We have investigated the optical H/sub 2/ and NO/sub 2/ sensing properties (change of absorbance) and also the electrical sensing effect (change of electrical resistance) for these two gases. A combined optical/electrical sensor for H/sub 2//NO/sub 2/ is proposed.