vertical tunneling transistor based on gr-hbn-χ3 borophene heterostructure with aa stack

In this paper, the electronic properties of vertical gr-hbn-χ3 borophene heterostructure (aa stack between gr and hbn layers), i.e., (gr-hbn-χ3_aa), have been investigated by density functional theory (dft). by using the tight-binding (tb) model and least-square fitting for tb and dft band structures, optimal tb parameters are calculated. by exploiting the non-equilibrium green function technique and capacitive model, we have investigated the vertical tunneling transistor (vtfet) based on gr-hbn-χ3_aa. also, the figure of merit (fom) of the device, such as the ion/ioff ratio, subthreshold swing, and intrinsic gate-delay time, has been extracted. we have concluded that decreasing the width of the graphene nanoribbon improves the switching ratio, subthreshold swing, and gate-delay time. also, compared to previous work (vtfet based on gr-hbn-χ3_ab), it is seen that changing the stack between gr and hbn layers has little effect on the fom of the device. the gate-delay time of the device is 0.011 ps at room temperature.