A high TCR material with Si1−xGex/Si MQWs for waterborne pathogen detection

The thermistor based on Si_1-xGe_x/Si MQWs structure is one kind of biomedical materials which used in waterborne pathogen detection. Si_1-xGe_x/Si MQWs structure has high temperature coefficient of resistance (TCR), which meets the requirements for the detection of exothermic phenomenon during the reaction. In this work the theoretical model of the material has been introduced. The energy gap in valence band between barrier valence band level and Fermi level is 0.16ev and 0.21ev in the experiment and theoretical analysis respectively. The TCR values with different structure of the MQWs (25% and 30% Ge content with 10 nm wide quantum well) are -2.84% and -3.25% in the calculation respectively. The TCR test experiment has been carried out and a TCR value of -2.3 %/K was obtained after data processing.