Effect of carrier number in density of states and quantum capacitance of with and without disorder GNR-FET on drain current

Abstract

In this paper with and without disorder grapheme nanoribbon (GNR) channel is being considered for different electrical parameters (Current, Number of carriers at steady state, Density of states, Quantum Capacitance). Due to increase in drain potential from 0 V to 0.7 V, the carrier concentration changes in channel region. Because of the dependence of channel potential on carrier concentration, the constant value carrier concentration cannot be considered to calculate drain current. Self-consistent field (SCF) method is utilized to calculate channel potential for the proposed model. The change in carrier concentration of channel is related to quantum capacitance. Quantum capacitance has a significant effect when drain to source bias is low. Density of states (DOS), dependent current expression is derived for with and without disorder grapheme nanoribbon (GNR) channel based field effect transistor (FET). Energy broadening due to the contact between grapheme nanoribbon (GNR) and metal leads is also considered to show effective carrier collection. The model also presents the short channel effect of device. The simulation of current-voltage, Density of states (DOS) using MATlab 2014a software is carried out.