High-Performance Junction-Free Field-Effect Transistor Based on Blue Phosphorene

Two-dimensional semiconductors have great potential in high-performance electronic devices. However, the common way of contacting them with metals to inject charge carriers results in contact resistance (leading to poor current delivering capability) and remains a bottleneck in the scaling of modern devices. We will discuss a junction-free field-effect transistor consisting of semiconducting monolayer blue phosphorene as channel material (with high carrier mobility) and metallic bilayer blue phosphorene as electrodes. The junction-free design minimizes contact resistance. Employing first-principles calculations along with the non-equilibrium Green’s function method, we demonstrate an ultra-low contact resistance, a high Ion/Ioff ratio of up to 2.6×10⁴ and a remarkable transconductance of up to 811 μS/μm.