Near room-temperature triethylamine sensor constructed with CuO/ZnO P-N heterostructural nanorods directly on flat electrode

Metal oxide-based chemiresistive gas sensors working at room temperature with high sensitivity for specific gas have been expected for many applications. Here, a near room-temperature and high-response triethylamine (TEA) gas sensor has been successfully fabricated by designing CuO/ZnO P-N heterostructure. By introducing a seed layer, ZnO nanorods directly grew on flat Al2O3 substrate with a facile and cost-effective hydrothermal method. Then, CuO nanoparticles were loaded onto the surface of ZnO nanorods to form P-N heterostructures via a simple wet-chemical method. The CuO-nanoparticles/ZnO-nanorods heterostructure exhibits higher response to 50 ppm TEA gas than that of pristine ZnO nanorods even at working temperature as low as 40 degrees C, owing to the formation of P-N heterojunction. The enhanced gas-sensing properties of CuO/ZnO sensor were discussed with a CuO/ZnO P-N heterojunction model in terms of depletion layer and modulation of potential barrier height. (C) 2015 Elsevier B.V. All rights reserved.