Doped armchair germanene nanoribbon exhibiting negative differential resistance and analysing its nano-FET performance

Density functional theory (DFT) combined with non-equilibrium Green's function (NEGF) formalism is performed to explore electronic properties (geometrical stability, band structure and density of states) and quantum transport properties (transmission spectrum and I-V characteristics) of armchair germanene nanoribbon (AGeNR) doped with various elements, such as Ga, In, Tl, As, Sb and Bi. A negative differential resistance is observed for each doped AGeNR. Our results indicate that the indium (In) atom doped AGeNR is the most geometrically stable structure and provides a maximum peak to valley current ratio (I-p/I-v = 1.95). Further, In atom doped AGeNR is proposed for field effect transistor (AGeNR-FET) formation using the high dielectric constant value of hafnium dioxide (HfO2 = 25) at different applied gate voltages (-0.5 V-0.5 V). Finally, AGeNR-FET parameters are also calculated which shows high transconductance i.e. 56,196.3 n Omega(-1), high charge mobility i.e. 2.6 x 10(4) cm(2) V-1 s(-1) and low subthreshold swing i.e. 39.39 mV/decade. Our findings have great application in digital devices and memory devices, and high frequency applications for future nanoelectronics and nanodevices.