The inevitable wall predicted by Moore’s Law is fast approaching, forcing scientists to innovate new methods of enhancing transistor performance not reliant on miniaturization. Recall that Moore's Law says that transistors shrink by a factor of 50% every two years, effectively doubling their numbers, but at the same time, the smaller transistors get, the closer they are to reaching the atomic levels where they lose their properties. To slow this impending doom, researchers at UC Santa Barbara have devised a compound semiconductor of nearly perfect quality, embedded with nanostructures containing ordered lines of atoms that can be manipulated with light.
The compound semiconductor is applicable in a wide range of applications, effectively creating more efficient solar cells, less risky and higher resolution biological imagining, and the ability to transmit massive amounts of data at ridiculously high speeds. Scientists paired the rare-earth element erbium (Er) with the element antimony (Sb) and embedded the resulting ErSb nanostructure into the semiconducting matrix of gallium antimonide (GaSb). The ErSb’s nanostructure compliments the structural pattern of the surrounding matrix and meshes perfectly without interrupting the atomic lattice to form a new structure capable of manipulating light energy in the mid-infrared range.
“The nanostructures are coherently embedded, without introducing noticeable defects, through the growth process by molecular beam epitaxy,” said Hong Lu, lead author of published study, “Secondly, we can control the size, the shape and the orientation of the nanostructures.”
Introducing the ErSb nanoparticles into the atomic lattice allows the compound semiconductor to absorb a wider spectrum of light due to a phenomenon called surface plasmon resonance, electron oscillations at the surface of a metal excited by light. By inducing this technique in a semiconductor, scientists hope to bridge the scale gap in which optics and electronics operate, allowing circuits to take advantage of the speed and data capacity of photons.
When infrared light waves graze the surface of the semiconductor, the electrons begin to resonate and oscillate at the same frequency as the infrared light particles. This preserves optical information at a small enough scale to become compatible with electronic devices, creating an entire slew of potential applications in solar cells, cancer fighting medical applications, and the new field of plasmonics.
The highly conductive nanostructure may even polarize electromagnetic radiation in a broad rage, establishing a new platform for applications in the infrared and terahertz frequency range. This effect may in turn be used to image the internal structure of a variety of materials, including the human body, without relying on the harmful x-rays; however, the technology needed to take full advantage of this frequency range is still an emerging field.
Via phys.org
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