Characteristics of solution-processed TFTs with In4ZnOx/SrTa2O6 thin films

TFTs with channel layer material of InZn
₄
O
_x
, and gate insulator materials of SiO
₂
and SrTa
₂
O
₆
(STA) were successfully fabricated using solution-process. STA is a high-k material with the dielectric constant of about 40 in amorphous state. Both these two kinds of TFTs are in saturation region at a low drain voltage of 5 V. The on/off current ratios of the TFTs with the gate insulator of SiO
₂
and STA are 3.8×10
⁴
and 3.1×10
⁵
. One order was increased by using the STA thin films. Meanwhile, the on voltage significantly decreased from -17 V to 1.5 V by using the STA thin films.