Design Of A Tin Dioxide Film Humidity Sensor Based On A Nano-silicon Pore Array

In this paper,two kinds of nanomaterials are combined to prepare an innovative composite material with traditional technology.The silicon nanoporous pillar array?Si-NPA?has a special micro/nano double structure.On the surface it forms a large number of sorting rules of the pore column,which is easy to adsorb water molecules.The gap between the pore columns make the transmission of water vapor more smooth,which can speed up the response time.Its unique structural and physical properties are the ideal choice for fabricating silicon-based semiconductor nanosensor substrate materials.SnO₂ is a common humidity sensitive material,with good adsorption,stability.So the combination of tin dioxide and silicon nanoporous pillar array can achieve the purpose of upgrading the humidity characteristics.The SnO₂/Si-NPA humidity sensors prepared by sol-gel method and anodic oxidation method show good humidity-sensitive properties,and the relative humidity increases,the capacitance value increases accordingly.The sol-gel element is characterized by high sensitivity,but large humidity hysteresis.The sensitivity is up to2349.3%under 1kHz.The maximum hysteresis is 62.3%.The capacitance value of element prepared by sol-gel changes greatly at 68%RH-100%RH,so it is suitable for humidity detection in high humidity range.The response time is about 252s and the recovery time is about 148s.The anodizing element is characterized by fast response and small humidity hysteresis.Response time is about 108s,recovery time is about 45s.The maximum hysteresis is 12.5%.Sensitivity conforms to the general humidity sensor standard.It reaches 491.9%under 1kHz.The capacitance value of element prepared by anodizing changes greatly at 23%RH-75%RH,so it is suitable for humidity detection in medium humidity range.It is concluded that SnO₂/Si-NPA prepared by anodic oxidation method is superior to SnO₂/Si-NPA prepared by sol-gel method.