Ultrafast 27 GHz cutoff frequency in vertical WSe<sub>2</sub> Schottky diodes with extremely low contact resistance.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32221285.
- Also identified by DOI 10.1038/s41467-020-15419-1 and PMC identifier 7101435.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
Ultra-thin two-dimensional semiconducting crystals in their monolayer and few-layer forms show promising aspects in nanoelectronic applications. However, the ultra-thin nature of two-dimensional crystals inevitably results in high contact resistance from limited channel/contact volume as well as device-to-device variability, which seriously limit reliable applications using two-dimensional semiconductors. Here, we incorporate rather thick two-dimensional layered semiconducting crystals for reliable vertical diodes showing excellent Ohmic and Schottky contacts. Using the vertical transport of WSe<sub>2</sub>, we demonstrate devices which are functional at various frequency ranges from megahertz AM demodulation of audio signals, to gigahertz rectification for fifth-generation wireless electronics, to ultraviolet-visible photodetection. The WSe<sub>2</sub> exhibits an excellent Ohmic contact to bottom platinum electrode with record-low contact resistance (~50 Ω) and an exemplary Schottky junction to top transparent conducting oxide electrode. Our semitransparent vertical WSe<sub>2</sub> Schottky diodes could be a key component of future high frequency electronics in the era of fifth-generation wireless communication.