Samsung Advanced Institute of Technology

This study investigates the hole and electron conduction properties of thin-film transistors

(TFTs) with tin monoxide (SnO) channel and indium tin oxide (ITO) source/drain (S/D)

electrodes. Compared to SnO TFTs with gold (Au) S/D electrodes, significant enhancement of

electron conduction was observed when adopting ITO S/D electrodes. The ITO electrodes

reduced the electron injection barrier, facilitating the formation of an electron inversion layer

in the SnO channel and inducing ambipolar conduction characteristics. The ambipolar SnO

TFT exhibited coexisting electron and hole channels, which induced a transition from normal

to abnormal conduction properties. These transitioning conduction characteristics were

analyzed, and a method to extract saturation mobility in ambipolar TFTs considering the

electron-hole (e-h) recombination effect was proposed. Furthermore, bias-stress stability tests

were conducted to examine the effect of the coexisting electron and hole channels on the

carrier-trapping properties. This analysis provides valuable insights into the electrical

characteristics of ambipolar TFTs, considering the coexisting electron and hole channels