Vanadium dioxide is a promising material for next-generation electronics

One of the first electronic components with which it was possible to control electric current was a conventional electromagnetic relay. After some time, the first germanium transistor was born, more modern silicon analogs of which work in all electronic devices without exception. And next-generation electronics can be built on other materials, in particular vanadium dioxide (VO2). The key feature of this material is that it is a dielectric at room temperature and converts into a conductor above 68 degrees Celsius. And such materials belong to the exotic class of dielectric transition metals.

Scientists have known about the unusual properties of vanadium dioxide for quite some time, but until recently they had no suitable explanation for these properties. It turns out that as the temperature rises, the crystal structure of this material changes, it changes from a transparent amorphous form to a metallic conductive form when passing through a point of 68 degrees. And the most remarkable thing is that such a transition is carried out very quickly, it takes about one nanosecond, which will make it possible to use this property of vanadium dioxide in various high-speed electronic devices.

“In addition to temperature, vanadium dioxide is sensitive to a number of other factors; the phase change of this material can occur under the influence of an electric field, light or electromagnetic radiation in the terahertz range,” says Adrian Ionescu, professor at the Swiss Ecole Polytechnique Federale de Lausanne, EPFL).

However, fully exploiting the potential of vanadium dioxide is actually more challenging than meets the eye. After all, processors and other highly integrated components of modern electronic devices operate at temperatures that often reach 100 degrees. In this case, the effect discovered by scientists earlier can help, it turns out that a small addition of germanium to a thin film of vanadium dioxide raises the phase transition temperature of this material to a level exceeding 100 degrees Celsius.

Note that vanadium dioxide elements have already been used in radio electronics. Researchers from the Nanolab laboratory have created ultra-compact modulation frequency filters that use switches based on the phase transition effect of vanadium dioxide. These filters are particularly effective in the Ka-band, between 28.2 and 35 GHz, which is heavily used in space communications.

The discoveries made by Swiss scientists will provide further scientific interest in using vanadium dioxide as the basis for next-generation electronic devices, which are not very fast, but very efficient in terms of the amount of energy required to operate them. The researchers speculate that vanadium dioxide devices could form the basis of new neuromorphic processors, processors that mimic the principles of the brain, high-frequency radars and laser scanners for self-propelled robot cars. S

ource: dailytechinfo.org