Threshold Voltage Extraction in the Saturation Regime Insensitive to the Contact Properties for Organic Thin-Film Transistors

In this work, the conventional threshold voltage ( V
_th
) extraction method assuming ohmic contacts in organic thin-film transistors (OTFTs) was shown to be difficult to obtain the intrinsic V
_th
values for devices with non-negligible contact properties. A simple V
_th
extraction method based on a modified analytical current-voltage expression in the saturation regime was thus proposed to exclude the influence of the contact properties. By applying the method to experimental devices of two different contacts, apparent V
_th
values close to the intrinsic values were obtained, which proved the method to be useful for accurate device characterization and modeling of OTFTs.