Modulation of I-V Characteristics in U-Shaped Armchair Graphene Nanoribbon-Based Tunnel Diode

Here, the transport characteristics of aU-shaped armchair graphene nanoribbon tunnel diode (AGNR-TD) are modulated by adopting a tight-binding model and non-equilibrium Green's function (NEGF) formalism. Initially, we examine a pristine AGNR (pAGNR) which exhibits ballistic current-voltage (I-V) characteristics. To convert ballistics nature to tunnel diode characteristic we considered U-shaped AGNR- TD by introducing a cut of depth (dc) at the upper edge of pAGNR. This pattern resulted in the formation of a single-barrier TD structure. As dc increases from 7.38 A to 22.14 A, negative differential resistance (NDR) is obtained with a peak-to-valley ratio (PVR) of 2.57. In addition, we analyzed the I- <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$V$</tex> nature and transmission probability by varying the potential barrier width (W<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</inf>). As W<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</inf> increases from 18.46 A to 35.5 A, the corresponding peak current decreases. However, the PVR value rises from 2.57 to 3.18 and the power consumption at the valley drops from 171 nW to 17 nW.