Fullerenes Bridge Conductive Gap in Organic Photovoltaics
Efficient cathode interlayers made of ionene polymers refined with pendant fullerenes
In contrast to common silicon-based solar cells, organic photovoltaics (OPVs) involve organic molecules in solar power generation. Materials in OPVs are abundant and processable, cheap and lightweight, and the modules can be made flexible and with tunable properties. The major disadvantage of such materials is that achieving longevity and high performance requires elaborate settings and architectures. Optimized combinations of materials that match the electrodes remain elusive.
Silver or gold metals form air-stable, processable cathodes, but they also lower the device potential. To overcome this problem, Yao Lui at Beijing University of Chemical Technology (China), and Thomas Russell and Todd Emrick at the University of Massachusetts, Amherst (USA), and their research groups, have developed a novel polymeric material to serve as an interlayer between the electrode and the active layer. This interlayer must be conductive and must lower the work function of the cathode by providing an interfacial dipole.
As an interlayer material, the researchers investigated a novel class of charged polymers, the ionene polymers. “Ionene polymers are polycations in which the charged moieties are positioned within the polymer backbone rather than as pendant groups,” the authors explain. This leads to a higher charge distribution than in conventional cationic polymers, and in addition, better tunability. Ionene polymers provide a useful interfacial dipole, but alone, they lack the required conductivity.
Therefore, the authors included fullerenes in the structural framework of the polymer layer. So-called “bucky balls”—fullerene spheres made solely from carbon—are already used as common acceptor molecules in OPV devices. They are highly conductive and have many other favorable properties.
The scientists prepared the fullerene–ionene interlayer material by innovating on conventional step-growth polymerization chemistry with novel, functional monomers. They assembled the OPV devices and included an interlayer. The result was an impressive boost in power conversion efficiency—on average three-fold—when compared to devices without the interlayer. Efficiencies of over 10% point to further applicability of these modular devices.
This work shows that a relatively simple modification to the composition of materials can improve the efficiency in organic electronics and can overcome intrinsic problems related to the combination of hard (electrodes) and soft (active-layered) materials.
Other news from the department science
Leibniz Prize for chemist Prof. Dr. Peter R. Schreiner
Germany's most important research funding prize goes to scientist at the University of Giessen
Non-toxic plasticisers for use in elastomers and thermoplastics
Bio-based plasticizers from Central Germany
Wood materials make for reliable organic solar cells
Kraft lignin improves the stability in organic solar cells thanks to its ability to form hydrogen bonds that acts as a sort of glue
Argonne and Idaho National Laboratories partner with CMBlu Energy for innovative long-duration energy storage project
The project aims to improve microgrids in cold climates and make fast charging of electric vehicles more affordable in underserved communities
Blue-green algae sugar instead of glyphosate
Cooperation project develops environmentally friendly glyphosate alternative
Using clay to combat eternal toxins
TU Freiberg clarifies basis for innovative PFAS filter made of clay
Unveiling a new era of imaging: Boston University engineers lead breakthrough microscopy techniques
Researchers made significant advancements in the field of vibrational imaging
Phasing out fossil fuels could save millions of lives
The mortality burden attributable to air pollution from fossil fuel use is considerably higher than most previous estimates - a phaseout of fossil fuels would have tremendous, positive health outcomes
Replicating the structure of bird feathers
The new material could be used in batteries or filtration
Quantum tool opens door to uncharted phenomena
Method can contribute to a better understanding of quantum materials
Recovering instead of shredding: recycling batteries more efficiently
KIT researchers are working with industry to develop a more sustainable recycling process to recycle materials from lithium-ion batteries more effectively
Industry 4.0: No impact on energy consumption?
To what extent does the digitalisation of industrial and manufacturing processes (Industry 4.0) improve energy efficiency and thus reduce energy intensity?
New approach to the sensible utilisation of carbon dioxide from car exhaust gases
"A method has been discovered that uses impure CO2 streams and enables a breakthrough in the synthesis of valuable chemicals and pharmaceuticals"
Most read news
Microbes could help reduce the need for chemical fertilizers
A coating protects nitrogen-fixing bacteria: Start-up to commercialise coated bacteria for large-scale use in regenerative agriculture
Inauguration of the world’s first pilot plant for the cost-efficient production of green methanol
Start-up C1 Green Chemicals AG and research partners develop fundamentally new production process
This is a battery
Two colored liquids bubbling through tubes: Is this what the battery of the future looks like?
Not so silver lining: Microplastics found in clouds could affect the weather
Low-altitude and denser clouds contained greater amounts of microplastics
Converting PFAS “forever chemicals” into valuable compounds
Scientists develop a new method to incorporate harmful perfluoroalkenes into N-heterocyclic carbene ligands
Graphene's proton permeability: A switch for future energy technologies
This discovery could lead to the development of more efficient hydrogen fuel cells and solar water-splitting devices
Lithium-ion batteries are no longer the gold standard in battery tech
On the way to safer and more powerful energy sources
New designs for solid-state electrolytes may soon revolutionize the battery industry
Scientists achieve monumental improvements in lithium-metal-chloride solid-state electrolytes
Vulcan officially opened its Lithium Extraction Optimisation Plant
Europe’s first plant for fully domestic lithium chemicals production, to secure Europe’s lithium supply chain for Battery Electric Vehicle manufacturers
CO2-free hydrogen: BASF receives funding approval for 54-megawatt water electrolysis plant
Proton exchange membrane (PEM) electrolyzer expected to produce up to 8,000 metric tons of hydrogen per year
More news from our other portals
New drug delivery system could reduce daily diabetes shots to just three a year
Dietary management drugs have transformed Type 2 diabetes care, but daily injection routines are challenging for some patients
Dunning-Kruger effect with muesli bars
Those who know the least consider themselves highly competent
Scientists use quantum biology, AI to sharpen genome editing tool
"This study represents an exciting advancement toward, understanding how we can avoid making costly ‘typos’ in an organism’s genetic code"
Aston University technology to combat the not-so sweet practice of honey fraud
Light technology to be used to detect if honey is blended with cheap additions
How stem cells and immune cells communicate
Lisec Artz Award for Simon Haas: Groundbreaking discovery of an unknown protective mechanism against blood cancer from stem cells
Naked Clams: The New Superfood Sensation Emerging from the Depths
Researchers found Naked Clams contain almost twice the amount of Vitamin B12 as blue mussels and have developed an efficient way to farm them
Fatty acid factory filmed at work
High-resolution images provide new insights into cellular fatty acid production: Potential for medicine and biotechnology
Pushers, overcrowded trains and phone zombies
Sprite presents the world's first vending machine that responds to the things that bother Generation Z the most
Award for innovation in the detection of PFAS compounds
Thuringian startup and Fraunhofer Institute receive Lothar Späth Award
Tönnies Group launches first nationwide "Meat Climate Platform"
100 guests at the Future Forum for Agriculture
‘Hot’ new form of microscopy examines materials using evanescent waves
“This microscope technology is completely new, so we’re still learning specifically how and where it can be applied”
The Largest Biotech City in Europe Will Soon Be Built
The entire BIO CITY complex will span an area equivalent to 10 football fields, total investment expected to reach around 7 billion euros
Could eating turkey ease colitis?
According to data in mice, extra tryptophan could reduce the risk of future colitis flares
analytica 2024: Food analysis for sustainable nutrition
From PFAS to microplastics: focus on new harmful substances
Breakthrough in the synthesis of artificial cells
Researchers develop artificial cells from synthetic materials
From the trough to the plate - digitally calculated
Computer program "ConTrans" estimates how much of an undesirable substance is transferred from animal feed to food
Are healthy foods automatically sustainable, too?
Perceptions about sustainability and healthy food choices are closely linked
Taking antibiotics back in time
“Recreating such an ancient molecule was exhilarating, akin to bringing dinosaurs or wooly mammoths back to life”
Study of sourdough starter microbiomes to boost bread quality and safety
USDA grant to fund research that may benefit those with celiac disease