Thickness dependent low-frequency noise characteristics of a-InZnO thin-film transistors under light illumination

The influence of illumination on the electrical characteristics of amorphous indium–zinc oxide (a-IZO) thin-film transistors (TFTs) has been investigated. The electrical properties are found to depend significantly on the active thickness (TIZO) of the a-IZO TFT. The active thickness is seen to play a major role in the carrier transport mechanism. Based on the carrier fluctuation model, the low-frequency noise (LFN) characteristics of a-IZO devices of varying thicknesses were evaluated before as well as after illumination. Similar to the results of DC and capacitance–voltage (C–V) measurements, the LFN characteristics too show that the light-induced carrier transport becomes significantly enhanced for relatively thick (TIZO ≥ 60 nm) a-IZO devices.