Sensing performance of EGFET pH sensors with CZTSe nanoparticles fabricated on glass substrates

In this work, the sensing membrane of an extended-gate field-effect-transistor (EGFET) pH sensor with CZTSe nanoparticles was fabricated on a glass substrate through a solution-based method. The CZTSe nanocrystals were synthesized successfully by using the metal sources in isophorondiamine (IPDA, C10H22N2) solution under a N2 flow at atmospheric pressure and at the reaction temperature of 235 ^°C. It was found that the average diameter of these nanoparticles was 20-30 nm. The resulting EGFET pH sensors with CZTSe nanocrystals exhibited good sensing performances owing to the large sensing surface-to-volume ratio. The pH sensitivity calculated from the linear relation between the drain-source current and the pH value was 7 μA/pH, and that calculated from the linear relation between the reference voltage and the pH value was 9 mV/pH.