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1080-O15-18

WO3-x Nanorod Arrays Based Sensors with High Sensitivity and Quick Response for Detecting Pollutants Xinpeng Wang1, Jie Lou2, Zhenbo Wang3, and Peter Xianping Feng1,4 1 Department of Physics, University of Puerto Rico, San Juan, 00931, Puerto Rico 2 Department of modern Physics, University of Science and Technology of China, Hefei, 230026, China, People's Republic of 3 Department of Applied Chemistry, Harbin Institute of Technology, Harbin, 150001, China, People's Republic of 4 Physics Department, Donghua University, Shanghai, 201620, China, People's Republic of ABSTRACT Tungsten oxide nanorod arrays deposited on the cylindrical substrate have been used for fabrication of a two-dimensional (2D) sensor. The sensibility and capacity towards methane and acetone at different temperatures have been examined. Experimental data have indicated that the newly designed sensor is highly sensitive to methane with low cross sensitivity towards possible mixed organic gas acetone, relying on the operating temperature. At room temperature (20 oC), a quick response time and recovery time of the sensor, less than 10 ms, have been obtained. INTRODUCTION Nanostructured metal-oxide-semiconductors (MOS) employed as different types of sensors have been studied for many years. The main attractions of the MOS sensors are their high sensitivity, small dimensions, low cost, and good compatibility [1]. The emphasis of a sensor is on its sensitivity, which highly depends on its surface-to-volume (STV) ratio[2-5]. The applications of the regular conventional MOS sensors or thin film sensors are limited due to low STV ratio. Single nanowire and nanowire arrays such as carbon nanotube, ZnO and WO3 have already been explored and are known to be promising candidates for sensing application because of their enormous STV ratios [6-9]. However, the yielding of these kinds of sensors requires post-growth processing, which restricts the development of these devices [2, 10-12].Such disadvantage drives one to substitute networked nanowire films for nanowire arrays [13]. In the present case, the tungsten oxide nanorod arrays have been directly synthesized using hot filament chemical vapor deposition (CVD). No post-growth processing was needed. Moreover, in our work we directly used as-synthesized sample to pursue the gas sensing test; no sample destruction had to be operated. This is different from the traditional method, which generally required a sample to be torn into small pieces. This kind of destroyed-free test progress is important for commercial usage of gas sensing device manufacturing. Several parameters of the sensor are generally investigated in order to reveal its sensing ability. Besides sensitivity, the response time and the operating temperature are regarded as crucial characters as well [14-16]. Both are significant because of the necessity of sensibility optimization in practical usage and commercial cost concern. In this letter, the sensing behaviors of nanostructured tungsten oxide arrays based on different gases and tempera