A IGZO-based light-addressable potentiometric sensor on a PET susbtrate

A new device on a polyethylene terephthalate (PET) substrate is proposed for light-addressable potentiometric sensor (LAPS). A Indium Gallium Zinc Oxide (IGZO) film is sputtered on the Indium Tin oxide (ITO)/PET substrate as the photosensitive semiconductor layer. A high-dielectric constant layer of NbOx is sputtered on IGZO as the sensing membrane. Photocurrent versus bias voltage curve is illustrated successfully with the ultra-violet (UV) LED illmination with ac signal modulaiton. pH sensitivity, linearity, drift and hysteresis is 68 mV/pH, 99%, 1.8 mV/h and 1.1 mV of this fabricatd device, respectively. The highest operation frequency is 30 kHz, which make it as a highly potential candidate for 2D chemical image sensor, especially first demostrated in a PET susbtrate.