42.3%。 This is the latest achievement announced by spire semiconductor on October 6, 2010. The triple junction gallium arsenide (GaAs) solar cell developed by the company has a peak efficiency of 42.3% and a condensing condition equivalent to 406 suns.

It is reported that this battery platform has been put into commercial use& nbsp;

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Generally speaking, the photoelectric conversion efficiency of solar cells is only 20% ~ 30%. The previous world record was an experimental battery produced by Spectrolab, a wholly-owned subsidiary of Boeing, in August 2009, with a conversion rate of 41.6%& nbsp;

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On November 22, 2010, another new record was born. Spectrolab announced that its latest ground solar cell c3mj + has begun mass production. The average photoelectric conversion efficiency of this series of solar cells can reach 39.2%, which is the highest among the solar cells that have been mass produced& nbsp;

  Wang Zhonglin, a professor at Georgia Institute of technology, is also experimenting with similar optical fiber based organic batteries. His laboratory has developed a hybrid battery containing optical fibers and zinc oxide nanowires attached to the outer wall of optical fibers. Although it has not been successful, Wang Zhonglin expects that this method can improve the efficiency by six times.

In the latest issue of nano communication, Ali javey, a chemist who holds a joint position between Lawrence Berkeley National Laboratory and the University of California, Berkeley, and his team reported that the light absorption of the nanocolumn array they developed is no less than or even better than commercial thin-film solar cells, but only uses very few semiconductor materials& nbsp;

Multi junction solar cells are commonly used in concentrated photovoltaic (CPV) applications. In 2010, breakthroughs were made not only in multi junction solar cells, but also in all aspects of solar technology development& nbsp;& nbsp;

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Let solar cells capture more sunlight & nbsp& nbsp;

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Improving the conversion efficiency of solar cells is an eternal task for scientists. At present, researchers are working hard to study the chemical processes that improve the efficiency of organic thin film batteries& nbsp;

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For example, the research group of Akita University in Japan has developed organic materials that convert ultraviolet rays into visible light and are transparent to visible light. The purpose is to make the ultraviolet rays that are not effectively used by solar cells can be used for photoelectric conversion so as to improve the conversion efficiency& nbsp;

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It is reported that when the material is coated on the amorphous Si thin film solar cell, the conversion efficiency is increased by 9% over the original value, and it is expected to achieve an efficiency of 22% when it is used on the solar cell with a conversion efficiency of 20%& nbsp;

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There are still many attempts to improve efficiency from the structure in 2010& nbsp;

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For example, Kyocera Corporation of Japan uses advanced methods to form high-quality microcrystalline silicon, and the thin film silicon solar cell constructed in series by superimposing the amorphous silicon layer and the microcrystalline silicon layer achieves a conversion efficiency of 13.8%& nbsp;

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Many American scientists have tried to improve the efficiency of the battery by increasing the light absorption capacity of the surface& nbsp;

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The problem with standard flat-panel batteries is that no matter whether they are made of organic or inorganic materials, part of the sunlight will be lost through reflection. In order to reduce this loss, the battery manufacturer coated the battery with an anti reflection coating or etched the surface of the battery to increase photon absorption& nbsp;& nbsp;

David Carroll, a professor of physics at Wake Forest University in the United States, uses a layer of vertical optical fiber on the polymer matrix that constitutes the foundation of the battery as a sunlight capture device. This layer of optical fiber protrudes from the surface like a rough stubble. Sunlight can enter the top of the optical fiber from any angle, and photons bounce inside the optical fiber until they are absorbed by the surrounding organic cells. It is found that the optical fiber increases the sunlight absorption by about half, and theoretically, the efficiency can exceed 15%. This enables organic photovoltaic technology to compete with silicon cells& nbsp;

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The surface of the sticker is a polymer film imprinted with a microstructure, which can change the direction of incident light, increase the probability of sunlight being absorbed, and improve the efficiency of the battery. The test of the National Renewable Energy Laboratory of the United States shows that the film can increase the output power by 4% ~ 12.5% on average& nbsp;

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In addition, Innovalight, headquartered in California, has developed a method of imprinting silicon nanoparticles, which can improve the amount of sunlight absorbed by traditional crystalline silicon solar panels& nbsp;

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In fact, nano wires, pores, bumps and other textures can greatly improve the performance of solar cells. But the challenge lies in how to extend to a large area. Many methods are too complex and can not solve this problem. In July 2010, the research team led by Cui Yi, a professor of materials science and engineering at Stanford University, invented a simpler and cheaper method to create large-area nano scale textures& nbsp;

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In the nano express, Cui Yi reported that his team had made a solar device with super hydrophobic surface and proof of concept. To make solar cells, researchers deposit metal and amorphous silicon on uneven surfaces. As a result, it absorbs 42% more light than a flat surface using the same amount of material. Cui Yi hopes that the nano scale texture makes it possible to manufacture high-efficiency thin-film solar cells with few materials& nbsp;

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"This study shows a simple but effective method to achieve controllable aggregation of nanospheres in a large area." Ali javey said, "this may be a path to more efficient thin-film solar cells without increasing the cost and complexity of the production process."& nbsp;& nbsp;

New solar cell systems appear frequently& nbsp;

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Cogenra solar, a company, installed a new type of solar panel in a winery in Northern California. This group of panels combines traditional solar photovoltaic cells and a set of waste heat collection system, which can generate electricity and heat at the same time& nbsp;

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In fact, there are still many scientific research teams in the United States that are developing similar technologies, all of which are looking beyond photovoltaic, hoping to develop other potential of solar energy. However, these technologies are still in the early stage of development& nbsp;

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In August 2010, engineers from Stanford University proposed and proved the feasibility of using photovoltaic and photothermal power generation processes at the same time. This process is called "photon enhanced thermoelectron emission" or Pete& nbsp;

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Since the active materials in solar cells can only react with specific spectra, most silicon solar cells can only convert 15% of the energy in sunlight into electricity, and more than half of the solar energy is wasted in the form of heat& nbsp;

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Up to now, no researcher has mastered a technology that takes into account both thermal energy utilization and photoelectric conversion. Nick Melosh, associate professor of materials science and engineering at Stanford University, selected a gallium nitride semiconductor material coated with a thin layer of cesium metal. This material can use light and heat to generate electricity at the same time, doubling the efficiency of existing solar cell technologies& nbsp;

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Melosh estimates that the Pete process can achieve an efficiency of 50% or higher when sunlight is concentrated, and even 60% when combined with the thermal conversion cycle, which is almost three times the conversion efficiency of the existing system. The research results of the group were published in nature materials science on August 1, 2010& nbsp;

  Javey said, "as long as it is 2 microns high, our nanopillar array can absorb 99% of photons, with a wavelength range between 300 and 900 nanometers, and does not need to rely on any anti reflection coating."& nbsp;

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There are also some researchers working on new anti reflection solar cell coatings. For example, Harry Atwater, a professor at the California Institute of technology, and his colleagues created metal thin films hundreds of nanometers thick by accurately cutting the material structure at the nano and micro levels. Atwater said that the goal of this project is to make the refractive index of the film exactly equal to the refractive index of air. This material will not bend any light, but will conduct completely without reflection& nbsp;

Looking at these methods, it is the new surface composed of nanoparticles that allows solar cells to capture more sunlight to make up for the inherent shortcomings of organic thin-film solar cells.

Similarly, the technology developed by Genie lens, a small startup in the United States, is to improve the surface absorbance. It sounds simpler - just stick a transparent sticker on the surface of the solar panel to increase the output power. This technology is not only low-cost, but also can be applied to installed panels, and can be applied to any kind of solar panels, including polysilicon and thin-film solar panels& nbsp;

On October 25, 2010, researchers at the Massachusetts Institute of technology announced that they had accurately revealed the working principle of furulene Diruthenium molecule. This will help scientists develop new types of batteries that store and release thermal energy instead of electrical energy& nbsp;

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After being irradiated by sunlight, etc., the molecule will absorb electromagnetic waves, heat it slightly from the outside, or add a catalyst, and the molecule will generate heat at a temperature of about 200 ℃, and then revert to the structure before the change, which can be repeated many times. Therefore, in principle, a battery made of the two ruthenium fuvalene can store and release heat energy on demand. However, ruthenium has two problems: scarcity and high cost. Through this research, scientists can find cheaper alternatives to ruthenium& nbsp;

At the University of California, a new type of graphene organic solar cell came out. Although the photoelectric conversion efficiency of graphene organic solar cells is not as high as that of silicon solar cells, it has a promising application prospect because of its low cost and good flexibility. For example, it can be made into power curtains and even power clothes.

At the Massachusetts Institute of technology, in October 2010, researchers showed samples of solar panels as thin as paper, so thin that they could even be printed with a printer. Although the conversion rate of these early samples is very low, like graphene solar cells, they have broad application prospects and can be pasted on windows or laptops. Researchers believe that the technology can be commercialized within five years& nbsp;& nbsp;

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In addition, a research team from Canada's Albert University and the National Institute of nanotechnology extended the service life of plastic solar cells from a few hours to eight months& nbsp;

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Desert is one of the best places to place solar panels. But the wind and sand in the desert will also block the solar panels from absorbing sunlight. For example, a large 10 MW solar power plant in the United Arab Emirates has reduced power production by 40% due to sandstorms& nbsp;

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Boston University Professor Malay Mazumder's research group has provided a new technology - self-cleaning solar panels. This is one of two solar panel cleaning technologies funded by NASA, which may serve Mars probes in the future& nbsp;

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The system utilizes the principle that dust particles are charged in a dry environment, so that they can be quickly removed after contacting the battery panel. It is reported that this system can remove 90% of the dust in a two minute cycle& nbsp;

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In September 2010, the BBC reported that MIT had developed a miniature solar cell, which was only a few billionths of a meter long and could repair itself to prolong the life of solar cells& nbsp;

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It is reported that the solar cell is mainly made of protein, a small amount of carbon and other materials, which can convert sunlight into electric charges for power supply. Because the sun can provide a continuous stream of light, this design and improvement excited the scientific community& nbsp;& nbsp;

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Cost reduction is the king& nbsp;

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At the same time of improving efficiency and performance, only by reducing costs can it be popularized& nbsp;

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The target of the new generation thin film solar cell production line built by Mitsubishi Heavy Industries in 2010 is to achieve an annual output of 50MW and a conversion efficiency of 15%. They estimated that the manufacturing cost of the module could be reduced to 75 yen / watt by 2020& nbsp;

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In addition, Suntech is also working with several international companies to find micro inverters. This is another electronic technology that will also improve the power of photovoltaic systems& nbsp;

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According to the technical review, China Suntech group is the world's largest producer of crystalline silicon solar energy systems. They find it difficult to further improve, so solar energy innovation has been transferred to electronic products& nbsp;

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Eric wesoff, a solar energy analyst, said: "engineers are taking other measures to improve the efficiency of photovoltaic cells to the maximum extent. They are more willing to try different electronic products."& nbsp;

The reduction of cost will help the application of solar energy to a broader space& nbsp;

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At the beginning of January 2010, a subsidiary of Toyota announced that it had developed a solar charging station that relied on solar cells to charge plug-in hybrid vehicles and electric vehicles. It has been adopted by Toyota City, Aichi Prefecture& nbsp;

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It is reported that this solar charging station is equipped with a solar power generation system and power storage equipment, and is connected to the commercial power grid. The surplus power generated by solar energy can be used in buildings with charging stations or sold to power companies. In case of disasters, it can also be used as an emergency power supply& nbsp;

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In the United States, New York also built the first solar electric vehicle charging station in 2010.