CO gas sensing properties of ZnO/ZnS core-shell nanowires

초록

The controlled synthesis of nanostructures with different shapes and morphologies has attracted considerable interest, because the sensing properties of nanostructures depend on their structure, shape, phase, size, and size distribution as well as their composition. This paper compares the responses of GaN nanostructures with different morphologies to hydrogen. The major process behind the interaction between the nanostructures and hydrogen is the chemisorption of the dissociated hydrogen on the GaN surface. The chemisorption creates an electron accumulation layer on the GaN surface that enhances its electrical conductance. The GaN nanostructure sample synthesized at 1,100°C with a higher ammonia flow rate showed a higher response to H2 gas than that synthesized at 1,000°C with a lower ammonia flow rate, which might be attributed to the higher surface-to-volume ratio of the former.