The breakthrough, published this week in Nature Materials, could lead to less expensive, more efficient ways to store solar energy in the form of hydrogen-based fuels. This could be a major step forward in the development of viable replacements for fossil fuels.
“Our approach is the first of its kind,” says lead researcher Associate Prof. Avner Rothschild, of the Department of Materials Science and Engineering. “We have found a way to trap light in ultrathin films of iron oxide that are 5,000 times thinner than typical office paper. This is the enabling key to achieving high efficiency and low cost. ”
Iron oxide is a common semiconductor material, inexpensive to produce, stable in water, and – unlike other semiconductors such as silicon – can oxidize water without itself being oxidated, corroded, or decomposed. But it also presents challenges, the greatest of which was finding a way to overcome its poor electrical transport properties. Researchers have struggled for years with the tradeoff between light absorption and the separation and collection of photogenerated charge carriers before they die out by recombination.
“Our light-trapping scheme overcomes this tradeoff, enabling efficient absorption in ultrathin films wherein the photogenerated charge carriers are collected efficiently,” says Prof. Rothschild. “The light is trapped in quarter-wave or even deeper sub-wavelength films on mirror-like back reflector substrates. Interference between forward- and backward-propagating waves enhances the light absorption close to the surface, and the photogenerated charge carriers are collected before they die off."
The breakthrough could make possible the design of inexpensive solar cells that combine ultrathin iron oxide photoelectrodes with conventional photovoltaic cells based on silicon or other materials to produce electricity and hydrogen. According to Prof. Rothschild, these cells could store solar energy for on demand use, 24 hours per day. This is in strong contrast to conventional photovoltaic cells, which provide power only when the sun is shining (and not at night or when it is cloudy).
The findings could also be used to reduce the amount of extremely rare elements that the solar panel industry uses to create the semiconductor material in their second-generation photovoltaic cells. The Technion team’s light trapping method could save 90% or more of rare elements like Tellurium and Indium, with no compromise in performance.
The Technion-Israel Institute of Technology is a major source of the innovation and brainpower that drives the Israeli economy, and a key to Israel’s renown as the world’s “Start-Up Nation.” Its three Nobel Prize winners exemplify academic excellence. Technion people, ideas and inventions make immeasurable contributions to the world including life-saving medicine, sustainable energy, computer science, water conservation and nanotechnology.
American Technion Society (ATS) donors provide critical support for the Technion—more than $1.74 billion since its inception in 1940. Based in New York City, the ATS and its network of chapters across the U.S. provide funds for scholarships, fellowships, faculty recruitment and chairs, research, buildings, laboratories, classrooms and dormitories, and more.
Kevin Hattori | Newswise Science News
'Stealth' material hides hot objects from infrared eyes
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Scientists print sensors on gummi candy: creating microelectrode arrays on soft materials
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Russian researchers together with their French colleagues discovered that a genuine feature of superconductors -- quantum Abrikosov vortices of supercurrent -- can also exist in an ordinary nonsuperconducting metal put into contact with a superconductor. The observation of these vortices provides direct evidence of induced quantum coherence. The pioneering experimental observation was supported by a first-ever numerical model that describes the induced vortices in finer detail.
These fundamental results, published in the journal Nature Communications, enable a better understanding and description of the processes occurring at the...
In a recent publication in the renowned journal Optica, scientists of Leibniz-Institute of Photonic Technology (Leibniz IPHT) in Jena showed that they can accurately control the optical properties of liquid-core fiber lasers and therefore their spectral band width by temperature and pressure tuning.
Already last year, the researchers provided experimental proof of a new dynamic of hybrid solitons– temporally and spectrally stationary light waves resulting...
Scientists from the University of Freiburg and the University of Basel identified a master regulator for bone regeneration. Prasad Shastri, Professor of...
Moving into its fourth decade, AchemAsia is setting out for new horizons: The International Expo and Innovation Forum for Sustainable Chemical Production will take place from 21-23 May 2019 in Shanghai, China. With an updated event profile, the eleventh edition focusses on topics that are especially relevant for the Chinese process industry, putting a strong emphasis on sustainability and innovation.
Founded in 1989 as a spin-off of ACHEMA to cater to the needs of China’s then developing industry, AchemAsia has since grown into a platform where the latest...
The BMBF-funded OWICELLS project was successfully completed with a final presentation at the BMW plant in Munich. The presentation demonstrated a Li-Fi communication with a mobile robot, while the robot carried out usual production processes (welding, moving and testing parts) in a 5x5m² production cell. The robust, optical wireless transmission is based on spatial diversity; in other words, data is sent and received simultaneously by several LEDs and several photodiodes. The system can transmit data at more than 100 Mbit/s and five milliseconds latency.
Modern production technologies in the automobile industry must become more flexible in order to fulfil individual customer requirements.
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