Design of the shape, size, and distribution of the array of crystalline ZnO nanowires

As an ongoing research in our laboratories we are investigating the development of a gas ionization sensor (GIS). GIS is one of the most efficient gas sensors in terms of selectivity, reversibility, fast response time, low noise, and durability. This gas detector is based on breakdown of the gases inside two-parallel plates biased with high electric potential. The incorporation of the nanowires (NWs) in GIS results in a decreased applied voltage on the device. As the structure, size, and distribution of NWs affect the amplification properties of electric field inside a gas detector, in this work a technique to optimize NWs geometrical shape and their distribution for achieving the highest electric field inside the gas sensor is studied. ZnO NWs were chosen for this purpose as ZnO NWs possess specific characteristics such as reversibility, sensitivity, long life, repeatability, and possibility to grow them with different geometrical shapes. The design of ZnO NWs grown using a low cost and high throughput electrochemical fabrication process is investigated. The induced electric field influenced by structural parameters of NWs apexes was assessed using finite element method (COMSOL).