The effect of interface states on the current-voltage characteristics in the sub-threshold region of three different types of III-V based transistor architectures has been studied using a drift-diffusion based numerical simulator Experimentally extracted interface state density profile is included in the simulation to analyze their effect on the sub threshold response of InGaAs based MOSFETs MOS HEMTs and tunnel FETs Based on the Fermi-level position at the oxide/semiconductor interface and the corresponding interface state density (D-it) the sub-threshold response for the three devices can vary with tunnel FETs is having the least sub threshold degradation due to D-it (C) 2010 Elsevier Ltd All rights reserved