Light sources or optical switches will cost less thanks to the possibility of using silicon. How to warp the structure of this material that is very common and abundant in nature in order to obtain optical properties, at the center of an Italian study published on Nature Materials.

(v.l. a.s.) A group of researchers at the University of Trento, FBK (Trento), Civen (Veneto Nanotech), the University of Brescia and Modena and Reggio Emilia and the CNR Institute of Nanosciences has demonstrated that it is possible to warp on a microscopic scale the structure of silicon so that it assumes new optical properties, previously completely absent in this material.

A study that might open a new scenario in the field of applications of silicon - already widely used for the manufacture of microprocessors and photovoltaic panels - which will be published in the December issue of Nature Materials, the scientific journal of international reference in field of new materials. 

To achieve this, researchers Massimo Cazzanelli (University of Trento), Federica Bianco (University of Trento), Elisa Borga (University of Trento), Mher Ghulinyan (Bruno Kessler Foundation) and Georg Pucker (Bruno Kessler Foundation) coordinated by Lorenzo Pavesi (University of Trento) have applied a very high pressure on small silicon strips thus breaking its crystal symmetry. Before the treatment, a beam of light will pass through the silicon without undergoing any changes; on the contrary, after compression the light that passes through the silicon will come out with a double frequency, thus with twice as much energy. A property that can be exploited for example in the manufacture of innovative light sources (for frequencies difficult to cover) or optical switches, replacing with silicon materials generally more expensive and not having other valuable properties as silicon does.The research work was initiated thanks to a grant from the Autonomous Province of Trento in 2008 that, under the last "Major Projects"call by PAT's United Research Fund, has fostered a fruitful scientific collaboration between the University of Trento and the Bruno Kessler Foundation. This collaboration was then extended to computational theoretical physicists at the University of Modena and Reggio Emilia and the CNR Institute of Nanoscience and, thanks to a project funded by the  Cariplo Foundation, to telecommunications engineers from the University of Brescia. 

Thusa team of scientists able to cover the entire chain of research was formed: from the design of the experiment, to the construction of the device, from the theoretical calculation, to the testing and conclusion study.