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 I-on/I-off ratio of up to 2.6 x 10(4) and a remarkable transconductance of up to 811 mu S/mu m.