[22p-S222-1~9] 21.1 Joint Session K

[22p-S222-4] Vgs-response characteristics in high-sensitivity a-InGaZnO TFT pH sensors

〇Kazushige Takechi¹, Hiroshi Tanabe¹, Shinnosuke Iwamatsu², Shunsuke Konno², Toru Yahagi², Yutaka Abe², Mutsuto Katoh² (1.NLT Technologies, Ltd., 2.Yamagata Research Institute of Technology)

Keywords:oxide-semiconductor thin-film transistor,top-gate effect,pH sensor

We discuss our high-sensitivity a-InGaZnO TFT pH sensor from the viewpoint of gate-to-source voltage (Vgs) response to small pH step variations. The high sensitivity results from the enhancement of parallel shift in the transfer characteristics through the top-gate effect. The a-InGaZnO TFT pH sensor having a sensitivity of as high as 450 mV/pH shows Vgs response to a pH step change of 0.1 with negligible hysteresis and good linearity.