The DOS ( E ) and T ( E ) of a rectangular barrier. (a) Schematic of a rectangular barrier of height 0.1 eV across the W14 GNR channel. (b) The DOS(E) with red arrow indicating region of reduced DOS(E) due to the introduction of the barrier at channel. The region near E = E
/2 (as indicated) is magnified as inset with DOS(E) in log-scale. Two discrete bound states, created by the inverted well at valence band-edge, as shown in (a). (c) The T(E) with red arrow indicates the receding T(E) away from E
/2 due to the 0.1 eV barrier. Results for U = 0 and that calculated from TB-π are also included for comparison.