Inkjet-Printed Oxide Thin-Film Transistors Using Double-Active Layer Structure

Inkjet-printed oxide thin-film transistors (TFTs) with a double-active layer structure were prepared to achieve better electrical properties and bias stability. The active layer was composed of an inkjet-printed In
₂
O
₃
layer on top of an inkjet-printed zinc-tin oxide with various In
₂
O
₃
ratios. The best electrical properties of the inkjet-printed double-active layer ZTO TFTs were obtained with 0.01 M of In
₂
O
₃
: a mobility of 8.6 cm
²
/V s, a threshold voltage of 2.76 V, a subthreshold slope of 0.52 V/dec, and an on-to-off current ratio > 10
⁶
. The electrical properties of the inkjet-printed double-active layer oxide TFTs were superior to those of the single-active layered TFTs.