High electric-field effects on short-channel polythiophene polymer field-effect transistors

Abstract

The field-effect mobility (FEM) in polythiophene (PT) polymer field-effect transistors (PFETs) increases with reduced channel lengths during high driving forces across the source and drain, which is contradictory to the decrease in mobility caused by short-channel effects in amorphous Si thin-film transistors. The longitudinal electric-field (across source and drain) dependence of the FE mobility is believed to create the rise in mobility once the longitudinal electric field exceeds a critical value of 105 V/cm. The high longitudinal electric field also modulates the influence of the gate bias upon the FEM in PT PFETs. With increased longitudinal electric field, the correlation between FEM and gate bias is largely enhanced.