MMaterialsgateNEWS 2012/06/27

Related MaterialsgateCARDS

Energy: Nano-Sandwich Technique Slims Down Solar Cells, Improves Efficiency

Researchers from North Carolina State University have found a way to create much slimmer thin-film solar cells without sacrificing the cells’ ability to absorb solar energy. Making the cells thinner should significantly decrease manufacturing costs for the technology.

“We were able to create solar cells using a ‘nanoscale sandwich’ design with an ultra-thin ‘active’ layer,” says Dr. Linyou Cao, an assistant professor of materials science and engineering at NC State and co-author of a paper describing the research. “For example, we created a solar cell with an active layer of amorphous silicon that is only 70 nanometers (nm) thick. This is a significant improvement, because typical thin-film solar cells currently on the market that also use amorphous silicon have active layers between 300 and 500 nm thick.” The “active” layer in thin-film solar cells is the layer of material that actually absorbs solar energy for conversion into electricity or chemical fuel.

“The technique we’ve developed is very important because it can be generally applied to many other solar cell materials, such as cadmium telluride, copper indium gallium selenide, and organic materials,” Cao adds.

The new technique relies largely on conventional manufacturing processes, but results in a very different finished product. The first step is to create a pattern on the substrate using standard lithography techniques. The pattern outlines structures made of transparent, dielectric material measuring between 200 and 300 nm. The researchers then coat the substrate and the nanostructures with an extremely thin layer of active material, such as amorphous silicon. This active layer is then coated with another layer of dielectric material.

Using dielectric nanostructures beneath the active layer creates a thin film with elevated surfaces evenly spaced all along the film – like crenellations at the top of a medieval castle.

“One key aspect of this technique is the design of the ‘nanoscale sandwich,’ with the active materials in the middle of two dielectric layers. The nanostructures act as very efficient optical antennas,” Cao says, “focusing the solar energy into the active material. This focusing means we can use a thinner active layer without sacrificing performance. In the conventional thin-film design, using a thinner active layer would impair the solar cell’s efficiency.”

The paper, “Dielectric Core-shell Optical Antennas for Strong Solar Absorption Enhancement,” is published online in Nano Letters. Lead author of the paper is Yiling Yu, a Ph.D. student at NC State. Co-authors include Drs. Vivian Ferry and Paul Alivisatos of the University of California, Berkeley. The research was supported, in part, by the U.S. Department of Energy.

Source: North Carolina State University – 25.06.2012.

Investigated and edited by:

Dr.-Ing. Christoph Konetschny, Inhaber und Gründer von Materialsgate
Büro für Material- und Technologieberatung
The investigation and editing of this document was performed with best care and attention.
For the accuracy, validity, availability and applicability of the given information, we take no liability.
Please discuss the suitability concerning your specific application with the experts of the named company or organization.

You want additional material or technology investigations concerning this subject?

Materialsgate is leading in material consulting and material investigation.
Feel free to use our established consulting services

MMore on this topic

New catalyst dramatically cheaper without sacrificing performance

Engineers at the University of Wisconsin-Milwaukee (UWM) have identified a catalyst that provides the same level of efficiency in microbial fuel cells (MFCs) as the currently used platinum catalyst, but at 5% of the cost. Since more than 60% of the investment in making microbial fuel cells is the cost of platinum, the discovery may lead to much more affordable energy conversion and storage devices. The material – nitrogen-enriched iron-carbon nanorods – also has the potential to replace the platinum catalyst used in hydrogen-producing microbial electrolysis cells (MECs), which use organic matter to generate a possible alternative to fossil fuels. "Fuel cells are capable of directly... more read more

A team of physicists from the University of Miami introduces a breakthrough in the understanding of high-temperature superconductivity

Researchers from the University of Miami (UM) are unveiling a novel theory for high-temperature superconductivity. The team hopes the new finding gives insight into the process, and brings the scientific community closer to achieving superconductivity at higher temperatures than currently possible. This is a breakthrough that could transform our world. Superconductors are composed of specific metals or mixtures of metals that at very low temperatures allow a current to flow without resistance. They are used in everything from electric devices, to medical imaging machines, to wireless communications. Although they have a wide range of applications, the possibilities are limited by temperature... more read more

Battery-powered devices could soon be a thing of the past thanks to a group of UK researchers who have created a novel energy harvester to power some of the latest wearable gadgets.

By strapping the energy harvester to the knee joint, a user could power body-monitoring devices such as heart rate monitors, pedometers and accelerometers by simply walking and not have the worry of running out of power and replacing batteries. Soldiers may find this device particularly useful as they often have to carry up to 10kg of power equipment when on foot patrol. The device has been presented today, 15 June, in IOP Publishing's journal Smart Materials and Structures by researchers from Cranfield University, The University of Liverpool and University of Salford. The energy harvesting device, which is designed to fit onto the outside of the knee, is circular and consists of... more read more

Scientists at the U.S. Naval Research Laboratory, Electronics Science and Technology Division, dive into underwater photovoltaic research to develop high bandgap solar cells capable of producing sufficient power to operate electronic sensor systems at depths of 9 meters.

Underwater autonomous systems and sensor platforms are severely limited by the lack of long endurance power sources. To date, these systems must rely on on-shore power, batteries or solar power supplied by an above water platform. Attempts to use photovoltaics have had limited success, primarily due to the lack of penetrating sunlight and the use of solar cells optimized more towards the unimpeded terrestrial solar spectrum. "The use of autonomous systems to provide situational awareness and long-term environment monitoring underwater is increasing," said Phillip Jenkins, head, NRL Imagers and Detectors Section. "Although water absorbs sunlight, the technical challenge is... more read more


Partner of the Week

Search in MaterialsgateNEWS

Books and products