Scientists work to convert sunlight to cheaper electricity at South Dakota State University. Research scientists are working with new materials that can make devices used for converting sunlight to electricity cheaper and more efficiently.
Assistant professor Qiquan Qiao in SDSU’s Department of Electrical Engineering and Computer Science said so-called organic photovoltaics, or OPVs, are less expensive to produce than traditional devices for harvesting solar energy.
Qiao and his SDSU colleagues also are working on organic light-emitting diodes, or OLEDs.
The new technology is sometimes referred to as “molecular electronics” or “organic electronics” — organic because it relies on carbon-based polymers and molecules as semiconductors rather than inorganic semiconductors such as silicon.
“Right now the challenge for photovoltaics is to make the technology less expensive,” Qiao said.
“Therefore, the objective is find new materials and novel device structures for cost-effective photovoltaic devices.
“The beauty of organic photovoltaics and organic LEDs is low cost and flexibility,” the researcher continued.
“These devices can be fabricated by inexpensive, solution-based processing techniques similar to painting or printing.
“The ease of production brings costs down, while the mechanical flexibility of the materials opens up a wide range of applications,” Qiao concluded.
Organic photovoltaics and organic LEDs are made up of thin films of semiconducting organic compounds that can absorb photons of solar energy.
Typically an organic polymer, or a long, flexible chain of carbon-based material, is used as a substrate on which semiconducting materials are applied as a solution using a technique similar to inkjet printing.
“The research at SDSU is focused on new materials with variable band gaps,” Qiao said.
“The band gap determines how much solar energy the photovoltaic device can absorb and convert into electricity.”
Qiao explained that visible sunlight contains only about 50 percent of the total solar energy. That means the sun is giving off just as much non-visible energy as visible energy.
“We’re working on synthesizing novel polymers with variable band gaps, including high, medium and low-band gap varieties, to absorb the full spectrum of sunlight. By this we can double the light harvesting or absorption,” Qiao said.
SDSU’s scientists plan to use the variable band gap polymers to build multi-junction polymer solar cells or photovoltaics.
These devices use multiple layers of polymer/fullerene films that are tuned to absorb different spectral regions of solar energy.
Ideally, photons that are not absorbed by the first film layer pass through to be absorbed by the following layers.
The devices can harvest photons from ultraviolet to visible to infrared in order to efficiently convert the full spectrum of solar energy to electricity.
SDSU scientists also work with organic light-emitting diodes focusing on developing novel materials and devices for full color displays.
“We are working to develop these new light-emitting and efficient, charge-transporting materials to improve the light-emitting efficiency of full color displays,” Qiao said.
Currently, LED technology is used mainly for signage displays. But in the future, as OLEDs become less expensive and more efficient, they may be used for residential lighting, for example.
The new technology will make it easy to insert lights into walls or ceilings. But instead of light bulbs, the lighting apparatus of the future may look more like a poster, Qiao said.
Qiao and his colleagues are funded in part by SDSU’s electrical engineering Ph.D. program and by National Science Foundation and South Dakota EPSCoR, the Experimental Program to Stimulate Competitive Research.
In addition Qiao is one of about 40 faculty members from SDSU, the South Dakota School of Mines and Technology and the University of South Dakota who have come together to form Photo Active Nanoscale Systems (PANS).
The primary purpose is developing photovoltaics, or devices that will directly convert light to electricity.
Jeanne Jones Manzer | Newswise Science News
Perovskite-silicon solar cell research collaboration hits 25.2% efficiency
15.06.2018 | Helmholtz-Zentrum Berlin für Materialien und Energie GmbH
Second heat source optimises heat pump system
12.06.2018 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH
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.
An international team of scientists has discovered a new way to transfer image information through multimodal fibers with almost no distortion - even if the fiber is bent. The results of the study, to which scientist from the Leibniz-Institute of Photonic Technology Jena (Leibniz IPHT) contributed, were published on 6thJune in the highly-cited journal Physical Review Letters.
Endoscopes allow doctors to see into a patient’s body like through a keyhole. Typically, the images are transmitted via a bundle of several hundreds of optical...
Light detection and control lies at the heart of many modern device applications, such as smartphone cameras. Using graphene as a light-sensitive material for...
Water molecules exist in two different forms with almost identical physical properties. For the first time, researchers have succeeded in separating the two forms to show that they can exhibit different chemical reactivities. These results were reported by researchers from the University of Basel and their colleagues in Hamburg in the scientific journal Nature Communications.
From a chemical perspective, water is a molecule in which a single oxygen atom is linked to two hydrogen atoms. It is less well known that water exists in two...
13.06.2018 | Event News
08.06.2018 | Event News
05.06.2018 | Event News
15.06.2018 | Materials Sciences
15.06.2018 | Ecology, The Environment and Conservation
15.06.2018 | Power and Electrical Engineering