Plastic or solar battery materials will be the favorite of the future

Spraying a material on the backpack allows people to charge mobile phones, MP3s, etc., while walking; the bus shelter covers this material on the rain canopy, and passengers can charge the phone while waiting for the car. This is not a science fiction movie but a real scene in Los Angeles. This magical material is a plastic solar cell material - the third generation of solar cell material following crystalline silicon, inorganic film. Now, this material, which is called the future darling of the solar power industry, has also been industrialized domestically.

Last week, the Nanjing Chemical Industry Park Zijin Kechuang District announced the news that the Nanjing Ouyinhao Organic Optoelectronics Co., Ltd. in the special zone has successfully produced organic thin-film solar cell materials. Dr. Xiao Shuyong, chairman of Ou Na Jun, said that compared to crystalline silicon and inorganic thin films, nano-scale third-generation plastic solar cell materials have many advantages, such as good flexibility, low cost, and high commercial value, and will become solar power generation. The industry's "new darling."

According to Dr. Xiao's introduction, there are 136 countries in the world that are popular in the application of solar cells. Among them, 95 countries are conducting research and development of solar cells on a large scale and are actively producing various new energy-saving products. At present, there are three generations of global solar cell materials. The first generation is crystalline silicon solar cell materials, including monocrystalline silicon and polysilicon. Currently, polysilicon solar battery materials are commonly used in the market. Although the photoelectric conversion rate is high, such materials have high pollution during the production process, raw materials cannot be degraded, and the process is complicated, the cost is high, and the energy consumption is high. The second generation is inorganic thin-film solar cell materials. Compared with the first-generation crystalline silicon materials, the process has been simplified, but still relying on high-vacuum process technology, equipment investment is very large, and rare-earth reserves have to be used in materials. One of the rare earth indium is very scarce and it is not easy to develop. The third generation is a plastic solar cell material, also known as organic thin film solar cell material. Its production process is simple, low energy consumption and low cost. This material is an organic compound that can degrade and is a green product. According to calculations, the current power generation efficiency of plastic solar cell materials is about 10%, and it can even reach 12%. The cost per watt of power generation is about one-tenth that of polysilicon cells, which has a high commercial value.

Dr. Xiao Shuyong introduced that since organic solar materials are nano-scale materials, they are of light weight and have a very small amount of use. The greatest advantage is their flexibility. Not only can the fabricated devices bend and fold, but they can also be formed into a solution-forming film, printed or painted. At the surface of the object, electricity is generated.

Xiao Shuyong emphasized that although the advantages of the third-generation plastic solar cell materials are outstanding and the market prospects are broad, the world has yet to achieve large-scale industrial production. Its application has not yet been promoted on a large scale. Nowadays, most of its customers are research institutes and R&D centers for large companies. At present, only a few research institutes around the world are able to develop and produce this product. Canada's OneMaterial Company specializes in the research, development and production of plastic solar cell materials. The company has mastered more than 10 global invention patents, and many invention patents have been transformed into products to enter the market, while maintaining cooperative relations with Samsung, GE, Sharp and other international companies. Xiao Runong's Nanjing Ou Nao Company, established in Nanjing Chemical Industry Park, has also set up a research and development laboratory and began trial production of plastic solar cells in September last year. It is understood that Ou Na Sheng company's production process technology is the world's leading, trial production of excellent product quality, the price is 10 times that of gold, the product has been provided for the use of Chinese Academy of Sciences and other domestic research institutes.

At present, Nanjing Ouernao Company has increased the development of the domestic market. In the future, the company plans to cooperate with large domestic manufacturers and research institutions, starting from similar “small projects” in the United States, and promoting plastic solar cell materials to the market. Scale production. Xiao Shuyong said that the company will be committed to changing the situation of solar energy companies relying on government policies, hoping to transform solar energy technology into technological products, instead of relying on policies to attach products, so as an efficient green renewable energy independent into the energy market competition.

It is understood that Nanjing's trial production of products has been in short supply, the company will soon set up factories in Nanjing Chemical Industry Park, expand production.

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Hot research direction

Some experts said that as long as the efficiency of plastic solar cells exceeds 10%, it has commercial application value. At present, its research mainly focuses on the development of multifunctional new materials and the improvement of device manufacturing technology. The open-circuit voltage of plastic solar cells is usually a few hundred millivolts and can exceed 1000 millivolts. Therefore, the internal resistance of the device is too large and has many defects. The short-circuit current is generally very low and is in the order of milliamperes. Therefore, improving the collection efficiency of photons, separating the interface of excitons, and reducing the internal resistance of solar cells to increase the short-circuit current have become the research focus in the field of plastic solar cells.

Research on improving the efficiency of organic solar cells has seen a lot of results in the past few years. The choice of materials goes through such stages as organic dyes, organic dyes/inorganic materials, organic dyes/organic materials, organic dyes/polymer materials, polymer materials, polymer materials/inorganic materials, and polymer materials/polymer materials; The structure has experienced stages such as single-layer devices, double-layer devices, and multilayer devices.

Foreign achievements

Plastic solar cells developed by the University of California at Los Angeles and Sumitomo Chemical include two layers that act on different wavelengths of light, one layer of polymer acting on visible light and the other layer acting on infrared light. The battery conversion rate was 10.6%.

Researchers at the University of Illinois used dyed plastic flakes to collect sunlight and concentrate it in a solar cell made of gallium arsenide, which can double the output energy of the cell. Currently, researchers have demonstrated that this method is suitable for a single solar cell. But they plan to make bigger, plastic pieces dotted with many tiny solar arrays. This will not only allow solar panels to generate more power, but also reduce the consumption of photovoltaic materials, thereby reducing panel costs.

The Swiss company for electronics and micro-technologies (CSEM) Brazil has entered the commercial development phase with the use of organic polymers instead of monocrystalline silicon to make solar cells. Their new technology can create larger areas of plastic solar panels to meet the needs of ordinary household electricity. If such solar panels are installed in open spaces such as building roofs, the scale of power generation will be considerable.

Researchers at the University of Sheffield and the University of Cambridge in the United Kingdom had a mass print process that used two different photosensitive materials to “print” a circuit structure with a thickness of only 60 nanometers on a plastic film. The entire manufacturing process is performed at a lower temperature and can be mass-produced using a "roll-to-roll" technology, and the process as a whole can significantly reduce energy consumption and material waste. The researchers said that the conversion efficiency of this polymer solar cell is currently 7% to 8%, and the next step is expected to increase to more than 10%, and it is expected to be commercially available in 5 to 10 years.