25 October 2021
Designing different diodes for 5G
Published online 27 October 2020
A new type of diode will enable future devices to access the ultrahigh frequencies on 5G and 6G mobile networks.
As fifth-generation (5G) wireless networks start to switch on around the world, there is a need for low-cost components, including diodes, that enable mobile devices to receive and handle the high radio-frequency signals. This demand will only increase when technology companies start preparing for sixth-generation (6G) communications, which will provide ultrafast downloads and augmented reality.
Now, Dimitra Georgiadou at Imperial College London, UK, Thomas Anthopoulos at King Abdullah University of Science and Technology (KAUST) in Thuwal, Saudi Arabia, and co-workers, have demonstrated a new type of diode that shows great promise for meeting 5G and 6G needs. Most importantly, the diodes can be manufactured quickly, easily and inexpensively at low temperatures over large-area substrates.
The researchers followed the design of Schottky diodes, which comprise junctions between metals and a semiconductor. They used adhesion lithography to arrange gold and aluminium electrodes, separated by a gap of just 15 nanometers. Then they filled the gap with zinc oxide, a low-cost, abundant semiconductor that is easily deposited from solution.
In tests using radio signals in the 5G bandwidths, the diodes handled frequencies greater than 100 gigahertz, which represents a significant improvement on other devices such as those using silicon microparticles. The adhesion lithography technique can also allow the diodes to be seamlessly integrated with other components such as antennas, capacitors and resistors in practical circuits.
“Adhesion-lithography is unique in the sense that it facilitates easy access to the nanoscale world while being compatible with large-area manufacturing of a variety of opto-electronic devices,” says Anthopoulos.
Georgiadou, D.G. et al. 100 GHz zinc oxide Schottky diodes processed from solution on a wafer scale. Nat. Electron. http://doi.org/10.1038/s41928-020-00484-7 (2020).