First Solar Cell Made of Highly Ordered Molecular Frameworks
June 22, 2015 | Karlsruhe Institute of Technology (KIT)Estimated reading time: 3 minutes
Researchers at KIT have developed a material suited for photo-voltaics. For the first time, a functioning organic solar cell con-sisting of a single component has been produced on the basis of metal-organic framework compounds (MOFs). The material is highly elastic and might also be used for the flexible coating of clothes and deformable components. This development success is presented on the front page of the journal Angewandte Chemie International Edition.
“We have opened the door to a new room,” says Professor Christof Wöll, Director of KIT Institute of Functional Interfaces (IFG). “This new application of metal-organic framework compounds is the be-ginning only. The end of this development line is far from being reached,” the physicist emphasizes.
Metal-organic frameworks, briefly called MOFs, consist of two basic elements, metal node points and organic molecules, which are assembled to form microporous, crystalline materials. For about a decade, MOFs have been attracting considerable interest of re-searchers, because their functionality can be adjusted by varying the components. “A number of properties of the material can be changed,” Wöll explains. So far, more than 20,000 different MOF types have been developed and used mostly for the storage or separation of gases.
The team of scientists under the direction of KIT has now produced MOFs based on porphyrines. These porphyrine-based MOFs have highly interesting photophysical properties: Apart from a high effi-ciency in producing charge carriers, a high mobility of the latter is observed. Computations made by the group of Professor Thomas Heine from Jacobs University Bremen, which is also involved in the project, suggest that the excellent properties of the solar cell result from an additional mechanism – the formation of indirect band gaps – that plays an important role in photovoltaics. Nature uses porphy-rines as universal molecules e.g. in hemoglobin and chlorophyll, where these organic dyes convert light into chemical energy. A met-al-organic solar cell produced on the basis of this novel porphyrine-MOF is now presented by the researchers in the journal Angewandte Chemie (Applied Chemistry). The contribution is entitled “Photoinduzierte Erzeugung von Ladungsträgern in epitaktischen MOF-Dünnschichten: hohe Leistung aufgrund einer indirekten elekt-ronischen Bandlücke?“ (photo-induced generation of charge carriers in epitactic MOF-thin layers: high efficiency resulting from an indirect electronic band gap?).
“The clou is that we just need a single organic molecule in the solar cell,” Wöll says. The researchers expect that the photovoltaic capac-ity of the material may be increased considerably in the future by filling the pores in the crystalline lattice structure with molecules that can release and take up electric charges.
By means of a process developed at KIT, the crystalline frameworks grow in layers on a transparent, conductive carrier surface and form a homogeneous thin film, so-called SURMOFs. “The SURMOF process is suited in principle for a continuous manufacturing process and also allows for the coating of larger plastic carrier surfaces,” Wöll says. Thanks to their mechanical properties, MOF thin films of a few hundred nanometers in thickness can be used for flexible solar cells or for the coating of clothing material or deformable components. While the demand for technical systems converting sunlight into electricity is increasing, organic materials represent a highly interesting alternative to silicon that has to be processed at high costs before it can be used for the photoactive layer of a solar cell.
About Karlsruhe Institute of Technology (KIT)
Karlsruhe Institute of Technology (KIT) is a public corporation pursuing the tasks of a state university of Baden-Wuerttemberg and of a national research center of the Helmholtz Association. The KIT mission combines the three core tasks of research, higher education, and innovation. With about 9,400 employees and 24,500 students, KIT is one of the big institutions of research and higher education in natural sciences and engineering in Europe.
Suggested Items
Connect the Dots: Designing for Reality—The Pre-Manufacturing Process
05/08/2024 | Matt Stevenson -- Column: Connect the DotsI have been working with Nolan Johnson on a podcast series about designing PCBs for the reality of manufacturing. By sharing lessons learned over a long career in the PCB industry, we hope to shorten learning curves and help designers produce better boards with less hassle and rework. Episode 2 deals with the electronic pre-manufacturing process. Moving from CAD (computer-aided design) to CAM (computer-aided manufacturing) is a key step in PCB manufacturing. CAM turns digital designs into instructions that machines can use to actually build the PCB.
Altus Equips SSTL with Advanced Cleaning Technology for Electronics
05/07/2024 | Altus GroupAltus Group, a leading supplier of capital equipment for the electronics manufacturing industry, has announced the successful installation of an advanced PCBA cleaning system at Surrey Satellite Technology Limited (SSTL).
RTX's Advanced Ground System for Space-based Missile Warning Now Operational
05/06/2024 | RTXAn advanced ground system for space-based missile warning developed by Raytheon, an RTX business, is now operational at the U.S. Space Force's Overhead Persistent Infrared Battlespace Awareness Center (OBAC).
BrainChip, Frontgrade Gaisler to Augment Space-Grade Microprocessors with AI Capabilities
05/06/2024 | BUSINESS WIREBrainChip Holdings Ltd, the world’s first commercial producer of ultra-low power, fully digital, event-based, neuromorphic AI IP, and Frontgrade Gaisler, a leading provider of space-grade system-on-chip solutions, announce their collaboration to explore the integration of BrainChip’s AkidaTM neuromorphic processor into Frontgrade Gaisler’s next generation fault-tolerant, radiation-hardened microprocessors.
Argonne, Toyota Collaborate on Cutting-Edge Battery Recycling Process
05/01/2024 | BUSINESS WIREThe U.S. Department of Energy’s (DOE) Argonne National Laboratory has recently launched a collaboration with Toyota Motor North America that could reduce the nation’s reliance on foreign sources of battery materials.