| 摘要 |
A method of fabricating a temperature sensing device based on printed silicon-carbon nanocomposite film is disclosed. This method includes high-crystal-quality Si nanoparticles (NPs) homogeneously mixed with carbon NPs and Si-C nanocomposites printed as negative temperature coefficient (NTC) thermistor. These mixtures of Si and C NPs are formulated into screen printing paste with acrylic polymer binder and ethylene glycol (EG) as solvent. This composite paste can be successfully printed on flexible substrates, such as paper or plastics, eventually making printable NTC thermistors quite low-cost. Si and carbon powders have size range of 10 nanometers to 100 micrometers and are mixed together with weight ratios of 100:1 to 10:1. More carbon content, higher conductivity of printed Si-C nanocomposite films keeping similar sensitivity of high-quality Si NPs. With homogeneous distribution of carbon particles in printed films, electrons can tunnel from silicon to carbon and high-conductivity carbon microclusters enhanced hopping process of electrons in printed nanocomposite film. The measured sensitivity 7.23%/°C of printed Si-C nanocomposite NTC thermistor is approaching the reported value of 8.0-9.5%/°C for intrinsic silicon bulk material near room temperature, with the quite low resistance of 10k©-100k©. This NTC thermistor is quite suitable for low-cost readout circuits and the integrated systems target to be disposable temperature sensors. |
