Solar cells and laser devices can be more efficient if the interaction between the matter and the light is improved. The momentum of photons is much lower in order of magnitudes than that of electron. Due to this, photons interact very weakly. Thus, controlling the momentum of photon could actually enable greater control over its interaction with the semiconductor devices.
Silicon is widely used in electronics. It is the most essential substance in the field of electronics. However, this silicon is not suitable for devices such as LEDs and solar cells. Silicon has lower efficiency while using in these devices. The semiconductor chips if used with integrating photonics can be very much useful for the improvisation of technology.
This research paper was presented by Yaniv Kurman of Technion (the Israel Institute of Technology, in Haifa); MIT graduate student Nicholas Rivera; MIT postdoc Thomas Christensen; John Joannopoulos, the Francis Wright Davis Professor of Physics at MIT; Marin Soljacic, professor of physics at MIT; Ido Kaminer, a professor of physics at Technion and former MIT postdoc; and Shai Tsesses and Meir Orenstein at Technion. The paper was published at the journal Nature Photonics. This all research or findings is based on a theoretical study.
Kaminer says that by changing the light instead of changing of silicon material can be very useful. Scientists and researchers usually design the matter in light interactions, but they don’t think to design the light side.
How can we change the light side?
By slowing down the light very much lower enough to bring the momentum of its individual photons, to get the photons momentum closer to that of its electrons. They showed that the light when passing through some kind of thin film material (multilayered–layered material is made of gallium arsenide and indium gallium arsenide layers) overlaid with layer of graphene, the photons in that light could be relaxed down by a factor of thousand.
Figure 1 – A thin-film material composed of layers of gallium-arsenide and indium-gallium-arsenide, overlaid with a layer of graphene to produce strong interactions between light and particles that can enable highly tuneable lasers or LEDs or solar cells.
Credits: Courtesy of this study researchers
The multilayered material varies the photons behavior when passing through it in a highly influenced way. In this way, the frequency of emissions from the material is controlled as much as 30 percent.
This entire process can shrink the wavelength of light to an atomic scale very effectively. The light can be absorbed or emitted by the semiconductor due to this shrinking of wavelength of light. Materials based on graphene can control these properties by altering the voltage applied to graphene layer. Thus, we can control the properties of light due to this. The quasiparticle known as Plasmon is produced due to interaction of electron and a hole. This Plasmon-Polariton is a kind of oscillation that takes place in an exotic material used in this research. The exotic material used in the research is a 2D layered material. These materials supports elastic oscillations on its surface in a tightly restricted area within the material.
This principle can also be used in solar cells as well due to the absorption of different wavelengths of light which can be a boon to the solar cell industries. This principle can also make the devices very much efficient.
Since, silicon material wasn’t used in this research, there is a possibility that these principles could also be applied to the silicon based devices as well. We can produce silicon in this plasmon-based devices by closing the momentum gap between the hole and electron, the team says. Not only silicon, but many other semiconductor materials could also be introduced in this plasmon-based devices.
MIT’s MISTI Israel program has supported this research work.
- Bunty B. Bommera
- Dakshata U. Kamble