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. We propose 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 the contact resistance. Employing first-principles calculations along with the non-equilibrium Green’s function method, we demonstrate a high Ion/Ioff ratio of up to 2.6 × 104 and a remarkable transconductance of up to 811 μS/μm.