Fig. 4: Toward high peak current density.
From: Toward high-current-density and high-frequency graphene resonant tunneling transistors
a–c Output characteristics at 300 K (a), output characteristics at 9.8 K (b), and peak current density | Jd,peak| (c) of a monolayer graphene, monolayer h-BN barrier RTT fabricated with the highest peak current density in this study. Measurements were not performed in Vd and Vg regions where NDR signals are not expected. The inset of (a) shows an optical micrograph of the device after fabrication and etching. The red and blue dashed lines indicate the ranges of the top and bottom graphene flakes, respectively. d Output characteristics of a monolayer graphene, four-layer h-BN barrier RTT at different temperatures T. e Partial enlargement within the gray dashed box in (d). f Peak current density and PVR as a function of T. g Room-temperature peak current density for different numbers of graphene and h-BN barrier atomic layers. h Comparison of the highest peak current densities of monolayer and bilayer graphene RTTs achieved in this study with those of 2D quantum-tunneling NDR devices in the literature (where RTD is resonant tunnling diode). References: MG (monolayer graphene)/BN (boron nitride)/MG11,12,23, BG (bilayer graphene)/BN/BG14,17, TG (trilayer graphene)/WSe2/MoS216, TG/MoSe2/WSe216, BG/WSe2/BG18, WSe2/BN/WSe219,24, MG/InSe/MG21, BP (black phosphorus)/BP/BP (twisted BP homostructure)22, MoS2/WSe226, BP/SnSe227, WS2/SnS232, and WSe2/SnSe234.
