University of Pittsburgh researchers have created a nanoscale light sensor that can be combined with near-atomic-size electronic circuitry to produce hybrid optic and electronic devices with new functionality. The team, which also involved researchers from the University of Wisconsin at Madison, reports in Nature Photonics that the development overcomes one of nanotechnology's most daunting challenges.
The group, led by Jeremy Levy, a professor of physics and astronomy in Pitt's School of Arts and Sciences, fashioned a photonic device less than 4 nanometers wide, enabling on-demand photonic interaction with objects as small as single molecules or quantum dots. In another first, the tiny device can be electrically tuned to change its sensitivity to different colors in the visible spectrum, which may forgo the need for the separate light filters other sensors typically require. Levy worked with Pitt postdoctoral researcher and lead author Patrick Irvin, postdoctoral researchers Daniela Bogorin and Cheng Cen, and Pitt graduate student Yanjun Ma. Also part of the team were University of Wisconsin-Madison researchers Chang-Beom Eom, a professor of materials science and engineering, and research associates Chung Wung Bark and Chad Folkman.
The researchers produced the photonic devices via a rewritable nanoelectronics platform developed in Levy's lab that works like a microscopic Etch A SketchTM, the drawing toy that initially inspired him. His technique, first reported in Nature Materials in March 2008, is a method to switch an oxide crystal between insulating and conducting states. Applying a positive voltage to the sharp conducting probe of an atomic force microscope creates conducting wires only a few nanometers wide at the interface of two insulators—a 1.2 nanometer-thick layer of lanthanum aluminate grown on a strontium titanate substrate. The conducting nanowires can then be erased with reverse voltage, rendering the interface an insulator once more.
In February 2009, Levy reported in Science that his platform could be used to sculpt a high-density memory device and a transistor called a "SketchFET" with features a mere two nanometers in size.
In this recent work, Levy and his colleagues demonstrated a robust method for incorporating light sensitivity into these electronic circuits, using the same techniques and materials. Photonic devices generate, guide, or detect light waves for a variety of applications, Levy said. Light is remarkably sensitive to the properties of such nanoscale objects as single molecules or quantum dots, but the integration of semiconductor nanowire and nanotube photonic devices with other electronic circuit elements has always been a challenge.
"These results may enable new possibilities for devices that can sense optical properties at the nanoscale and deliver this information in electronic form," Levy said.
Morgan Kelly | EurekAlert!
Astronomers find unexpected, dust-obscured star formation in distant galaxy
24.03.2017 | University of Massachusetts at Amherst
Gravitational wave kicks monster black hole out of galactic core
24.03.2017 | NASA/Goddard Space Flight Center
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.
Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
24.03.2017 | Materials Sciences
24.03.2017 | Physics and Astronomy
24.03.2017 | Physics and Astronomy