Figure 3. pH sensitivities of the IZO-based neuromorphic transistor measured in single-gate mode.

(a) Transfer curves of the neuromorphic transistor measured by using the sensing gate G₁ at V_DS = 0.1 V. The pH value of the solution droplet on the sensing gate G₁ is changed from 4 to 10 at a step of 2. The inset shows the measurement schematic. (b) The sensitivity in terms of V_R shift. The data can be fitted linearly by the black line. A sensitivity of ~37.5 mV/pH and a linearity of ~0.995 are obtained.