Unipolar n-Type Black Phosphorus Transistors with Low Work Function Contacts

• DOI: 10.1021/acs.nanolett.7b05192
• Publication Date: 2018-04-06T06:06:13Z
• Authors: Ching-Hua Wang; Jean Anne C. Inco...; Connor J. McClellan; Andrew C. Yu; Michal J. Mleczko; Eric Pop; H.-S. Philip Wong
• Keywords: Ambipolar diffusion

Black phosphorus (BP) is a promising two-dimensional (2D) material for nanoscale transistors, due to its expected higher mobility than other 2D semiconductors. While most studies have reported ambipolar BP with stronger p-type transport, it important fabricate both unipolar p- and n-type transistors low-power digital circuits. Here, we report low work function Sc Er contacts, demonstrating record high current of 200 μA/μm in 6.5 nm thick BP. Intriguingly, the electrical transport as-fabricated, capped devices changes from behavior after month at room temperature. Transmission electron microscopy analysis contact cross-section reveals an intermixing layer consisting partly oxidized metal interface. This results Schottky barrier between BP, leading transistor. suppressed favorable logic circuits ensure lower off-power consumption.