Morphological Investigation and Ph Sensing Properties of Β-Ga2o3 Egfet-Ph Sensor

Abstract

In our study, β-Ga2O3 particles of various morphologies deposited on FTO glass substrates through hydrothermal method under different pH conditions and pre-stirring temperatures. The particles examined using XRD, FESEM, FTIR and Raman spectroscopy instruments. The results showed that the β-Ga2O3 microrods prepared with pH=3.15 solution at different pre-stirring temperatures followed by hydrothermal reaction had several crystalline orientations ([−401], [002], [403]). The FTIR and Raman spectra measurements confirmed the existence of Ga−O−Ga and Ga−OH bending modes. In the range of pH=3-11, the EGFET-pH sensor prepared with β-Ga2O3 microrods shown a high current-pH sensitivity of 0.541 (mA)1/2 /pH with a linearity of 97.83 % and a high voltage-pH sensitivity of 73.99 mV/pH with linearity of 96.85 %. These results suggest that β-Ga2O3 microrods have pH sensitivity higher than the ideal Nernstian response. This confirms the use of β-Ga2O3 microrods as a sensing membrane in high-performance pH sensors or biosensors.

Keywords: β-gallium oxide, hydrothermal deposition, β-Ga2O3/FTO, EGFET-pH sensor