News from September 30, The flagship technology of the 2017 Nobel Prize in Chemistry: perovskite solar cells, Cheng Yibing's team from Wuhan University of Technology has achieved a substantial breakthrough and is in line with the ideal Large-scale applications are getting closer.
In an exclusive interview with a reporter from Science and Technology Daily in his laboratory this morning, Cheng Yibing said: The 5cm x 5cm plastic substrate flexible perovskite solar cell module developed by the The team successfully passed the national photovoltaic quality supervision. on August 8. Third-party certification by the inspection center resulted in a module conversion efficiency of 11.4%, far surpassing the world record of 10.5% conversion efficiency for a flexible perovskite solar cell module of 5 cm x 5 cm announced by the Japanese Toshiba on September 25. year.The preparation technology of 10cm x 10cm glass substrate perovskite solar cell modules has also achieved a major breakthrough. The module efficiency verified by the National Photovoltaic Quality Supervision and Inspection Center is 13.98%, ranking first in the international third-party verification efficiency of similar products.
The image shows: a 5cm x 5cm flexible battery on a plastic substrate
Perovskite solar cells are one of the top ten advances international scientists and technologies in 2013 selected by Scientific Magazine. Firstly, it is a new photovoltaic system which is expected to further reduce the price of photovoltaic energy production. Cheng Yibing's team from Wuhan University of Technology has been engaged in the development of production technology for this module for many yearsof photovoltaic product.
Not long ago, Clarivate Analytics published the 2017 Citation Winners. Since 2002, 45 Citation-winning scientists have won the Nobel Prize, so this prize is considered the “benchmark of the Nobel Prize.
This year, three Clarivate Analytics winners won the Citation Laureate award in the field of chemistry. The third prize was awarded to Tsutomu Miyasaka of Japan, Nam-Gyu Park of South Korea and Henry J. Snaith of the United Kingdom for their discovery and application of perovskite materials. Rewarded for achieving efficient energy conversion.
The 2017 Nobel Prize in Chemistry will be announced on October 4, Beijing time Cheng Yibing learned that “perovskite solar cell technology” has become the 2017 Nobel Prize in Chemistry "After that, it was very exciting. The breakthroughs made by Cheng Yibing's team in the two preparation technologiesof perovskite photovoltaic modules above indicate that Chinese researchers are leading the world in perovskite photovoltaic module preparation technology.
Whether he wins the prize or not, he has advanced technology, which is no worse than winning the prize.
Functional components of thin films deposited on the surface of solar cells
Thin film solar cells are new photovoltaic devices that alleviate the energy crisis. Thin film solar cells can be used in inexpensive ceramic, graphite and metal materials. It is made of different materials such as wafers as substrates, and the thickness of the film that can generate voltage is only of a few µm. The current conversion efficiency can reach up to 13%. In addition to being flat, thin film solar cells can also be tranformed into non-planar structures due to their flexibility. They have a wide range of applications and can be combined with or as part of buildings. applications.
With the increasing depletion of coal, oil, natural gas and other energy sources and increasing environmental pollution, people urgently need to find new sources of energy. clean and renewable energy. As an infinitely renewable and non-polluting land energy source, the application of solar energy has attracted increasing attention, and the development of solar cells that convert solar energy into electrical energy has rapidly developed. Currently, commercialized crystalline silicon solar cells have the highest photoelectric conversion efficiency, but due to the limitations of material purity and preparation processes, their cost is high, making it difficult to improve.ion of conversion efficiency or cost reduction. Thin-film solar cells can achieve photoelectric conversion with just a few µm thickness, making them an ideal material to reduce costs and improve photon recycling.
A battery is an energy conversion and storage device. It converts chemical or physical energy into electrical energy through reactions. A battery is a chemical energy source composed of two electrochemically active electrodes of different compositions, the positive and negative electrodes, respectively. The two electrodes are soaked in an electrolyte which can ensure the conduction of the support. When connected to an external medium, they convert their internal energy. chemical energy provides energy. As an electricity storage device, when two metals (usually metals with different properties) are immersed inn the electrolyte, they can conduct electricity and generate a certain electromotive force between the “plates”. The magnitude (or voltage) of the emf is related to the metal used, and different types of batteries have different emfs.
The performance parameters of the battery mainly include electromotive force, capacity, specific energy and resistance. The electromotive force is equal to the work done by the non-electrostatic force (chemical force) of the battery when a positive unit charge moves from the negative electrode to the positive electrode through the interior of the battery. The electromotive force depends on the chemistry of the electrode material and has nothing to do with the size of the battery.
Why can't crystalline silicon cells be used to make flexible thin-film solar panels?
The thin film deposited on the surface of the solar cell generally includes the following functional components:
1. Light absorption layer (absorbing layer): The light absorption layer of solar cells is the most critical thin film component. It can absorb light energy and convert it into electrical energy. Common light-absorbing layer materials include silicon (Si), copper-indium-gallium selenide (CIGS), copper-indium-sulfur selenide (CISS), etc.
2. Transparent conductive layer: The transparent conductive layer is used to collect the current generated by the photovoltaic cell and transmit it to the external circuit. Common transparent conductive layer materials include tin oxide (SnO2) and indium tin oxide (ITO).
3. Light-reflecting layer (rear reflector): the light-reflecting layer is located between the light-absorbing layer and the ssubstrate to improve the use of light. It is generally made of metal or metal oxide, such as aluminum (Al), silver (Ag) or aluminum foil (Aluminum Foil).
4. Passivation layer: The battery protective layer is used to protect the surface of the photovoltaic cell from damage caused by the external environment, while reducing the contact between the photovoltaic cell and environmental impurities. Common battery protective layer materials include aluminum oxide (Al2O3), silicon nitride (Si3N4), etc.
5. Encapsulation layer: The encapsulation layer is used to protect photovoltaic cells from external environments such as humidity, oxygen and dust. Common materials for encapsulation layers include polymeric materials, such as epoxy resin (Epoxy Resin), polymethyl methacrylate (PMMA), etc.
TheCrystalline silicon wafers are very easy to break and are more fragile than cookies. If they are made into thin films, they will break easily.
Crystalline silicon solar cell modules now have a hard substrate, most of which are glass, some are aluminum plates, and some are PCB boards. PCB boards are usually made of small batteries of components and adhesive battery sheets.
Amorphous silicon can be made into flexible thin-film solar cells.
Flexible thin film solar cells also include copper indium gallium selenide materials and dye sensitized materials.