A breakthrough has been made in the field of electronic devices with the discovery of a new form of ultrathin phosphorus. This blue form of phosphorus can be finely tuned to enhance the injection of charge carriers into transistors, which is expected to significantly improve the performance of next-generation electronics.
Two-dimensional semiconductors like graphene and transition metal dichalcogenides have been crucial in driving the miniaturization of electronic devices. They provide ultrathin channels for the transport of charge carriers in field effect transistors (FETs). FETs are essential components in modern circuitry as they control the flow of current through their channels using applied voltage. However, the presence of electric resistance at the interfaces between semiconductor channels and metal electrodes has limited charge injection and hindered the full potential of FETs.
Addressing this contact resistance is crucial for enhancing the current delivery capability and overall performance of FETs. To tackle this challenge, researchers led by Udo Schwingenschlögl have developed a junction-free FET using a newly discovered two-dimensional blue phosphorus called blue phosphorene. Blue phosphorene exhibits semiconductor properties on its own but becomes a metal when stacked into a bilayer configuration.
The team utilized a monolayer of blue phosphorene as the channel, positioned between two metallic blue phosphorene bilayers that function as electrodes. The use of the same material for the channel and electrodes creates a continuous structure, reducing resistance. Computer simulations were conducted to investigate the quantum transport in this FET design, considering two different orientations: armchair and zigzag. The proposed FET design successfully facilitated electron transfer between the channel and electrodes while meeting the criteria for switching and amplification. It outperformed devices based on other two-dimensional materials like black phosphorene and monolayer molybdenum disulfide.
The researchers plan to further enhance the performance of FETs by addressing current leakage between the transistor gate and electrodes using van der Waals materials. These materials consist of weakly interacting sheets held together. Additionally, they aim to extend their findings to magnetic materials for the development of spintronic devices.
The study detailing this groundbreaking research has been published in the journal npj 2D Materials and Applications.