Ga2O3 nanorod-based extended-gate field-effect transistors for pH sensing

In this study, the pH-sensing characteristics of gallium oxide (Ga2O3) nanorods based on an extended-gate fieldeffect transistor were grown on the ITO/glass via chemical bath deposition. Ga2O3 nanorods were observed using scanning electron microscopy, X-ray diffraction, energy-dispersive spectrometry, transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and Raman spectrum instruments. The experimental results showed that the alpha-Ga2O3 nanorods had several crystalline orientations ([10 4], [110], [024], [116]) after being annealed at 400-600 degrees C for 1 h. The FTIR and Raman spectrum measurements confirmed the existence of Ga-O and Ga-OH bending modes. As observed by the TEM, the nanorods had a good crystal quality and atomic lattice arrangement. In addition, the Ga2O3/ITO pH sensor possessed high pH sensitivity (51.59-64.29 mV/pH), good linearity (98.5%-99.8%), and long-term stability (drift, 2.75 mV/h; pH = 7). Overall, the alpha-Ga2O3 could be used as a low-cost FET-based manufacturing sensor for pH or biosensors.

Automated summary

The study investigated the pH-sensing characteristics of gallium oxide (Ga2O3) nanorods grown on ITO/glass via chemical bath deposition. The nanorods exhibited multiple crystalline orientations after annealing, with the presence of Ga-O and Ga-OH bending modes confirmed by FTIR and Raman spectra. The Ga2O3 nanorods showed good crystal quality and atomic lattice arrangement, with high pH sensitivity, good linearity, and long-term stability, making them suitable for use as low-cost FET-based sensors for pH or biosensors.