▎ 摘 要
The width-dependent performance of armchair GNRs-FETs is investigated by developing a fully analytical gate capacitance model based on effective mass approximation and semiclassical ballistic transport. The model incorporates the effects of edge bond relaxation and third nearest neighbor interaction as well as thermal broadening. To calculate the performance metrics of GNR-FETs, analytical expressions are used for the charge density, quantum capacitance as well as drain current as functions of both gate and drain voltages. Intrinsic gate delay time, cutoff frequency and I-on/I-off ratio are also calculated for different GNR widths. Numerical results for a double-gate AGNR-FET operating close to quantum capacitance limit show that nanoribbon widths of about 3-4 nm at most are required in order to obtain optimum on/off performance. (C) 2013 Elsevier B.V. All rights reserved.