Scientists from MISiS have developed a flexible solar battery three times cheaper than silicon panels

Source: http://tass.ru/nauka/3193630

MOSCOW, April 11. /TASS/. Scientists from the Research Technological University "MISiS" together with colleagues from the University of Texas at Dallas have developed a flexible solar battery based on a metal-organic compound, the cost of which is at least three times lower than silicon panels, the university's press service reports.

Flexible solar battery developed by NUST MISIS scientists

“A group of scientists from NUST MISIS, led by Professor Anvar Zahidov, presented the technology for creating a thin-film photocell based on a hybrid metal-organic compound - perovskite, which allows converting the energy of solar radiation into electrical energy with an efficiency above 15%, with planned indicators of more than 20%... Today the estimated cost per square meter of perovskite solar panels is less than $100, while the best silicon panels cost $300 per square meter. In mass production, the difference will be 4-6 times,” the report says.

Silicon-based solar cells are expensive due to the high-tech, energy-intensive and toxic production of silicon. In addition, they are much more fragile and less flexible compared to those developed by Russian scientists. The peculiarity of perovskite technology is that the active layers of solar cells based on it can be deposited from liquid solutions onto thin and flexible substrates. This allows you to place solar panels on surfaces of any curvature: window translucent “energy curtains” of houses and cars, facades and roofs of buildings, consumer electronics and much more.

“The main advantage of hybrid perovskites is their ease of production from common metal salts and industrial organic chemicals, rather than from the expensive and rare elements used in high-efficiency semiconductor analogs such as silicon and gallium arsenide solar cells. Equally important, perovskite-based materials can be used to print photoelectronics not only on glass, but also on other materials and surfaces. This makes the batteries much cheaper than with more complex methods of producing thin-film solar cells,” Zahidov said, as quoted in the report.

A significant reduction in the cost of producing solar panels will help increase the share of clean, renewable energy sources in the overall energy pie.

Russian scientists will develop a new type of plastic solar cells

Source: http://tass.ru/ural-news/3174602

EKATERINBURG, April 4. /TASS/. Russian scientists plan to develop the first prototypes of a new generation of plastic solar cells by 2018, the correspondent reported. TASS researcher at the Directorate for Scientific Innovation Activities of the South Ural State University state university Oleg Bolshakov. The project is being implemented with grant support from the Russian Science Foundation.

“Together with colleagues from the Moscow Institute of Organic Chemistry, we have been working on the creation of new-generation plastic thin-film solar cells for 1.5 years. The first batch of material for solar panels is already ready, it will be tested for 2-3 months in a special laboratory at the University of Edinburgh in Scotland,” Bolshakov said. “Russia does not yet have the necessary certified laboratories, so we turned to foreign specialists. According to the plan, by 2018 we will release the first prototypes,” he added.

According to scientists, the main feature of the new type of solar cells is organic photosensitive material. “Such batteries will not be toxic, and they also do not require large quantity photosensitive material is 1000 times less compared to batteries of previous generations, so they will also be the most affordable. For these reasons, developments in this direction are being carried out all over the world. But there are no analogues of our technology yet, so the implementation of our project will give us great advantages in the alternative energy of the future,” added Bolshakov.

He also noted that on this moment specialists will have to identify the statistical relationship between the structure of materials and efficiency. “Each photocell is characterized by two main parameters - stability and energy efficiency. It is necessary to determine the most successful options from those that we sent to the laboratory, after which they can already be applied to various surfaces. Further scientific work will be associated with the improvement of materials,” the scientist explained.

The world is confidently moving towards a revolution in energy-saving technologies. One of the latest achievements in this area belongs to the International Research Group, which was formed by the University of Texas at Dallas and the Moscow Institute of Steel and Alloys (MISiS). Scientists have developed a method for creating a solar cell based on perovskite. Unlike traditional analogues, which are based on silicon, the efficiency of the new product is much higher. At the same time, the cost of the solar battery of the future is reduced. Researchers are confident that plastic, lightweight, affordable perovskite devices will eventually find wide application, will be in demand and will completely replace outdated silicon analogues.

Analysis of silicon solar cells began in the twentieth century.

The existing technology has a number of disadvantages. This is the toxicity and energy intensity of silicon production. Therefore, the process turns out to be expensive. Silicon is also unreliable, has insufficient ductility and is very heavy in panels. Therefore, the scope of application of this chemical element is too narrow. Scientists predict that metal-organic perovskite will be able to solve all these problems.

New research has allowed fruitful work on a prototype tandem device that consists of carbon nanotubes and photovoltaic components. This development involves a combination of perovskite parts and traditional silicon. The installation effectively converts available ultraviolet rays into electricity and increases battery efficiency by 15%.

— The main advantage of hybrid perovskite is the ease of its production from standard sources: industrial organic chemical compounds and metal salts. While highly efficient semiconductor analogues in the form of solar cells, based on gallium arsenide and silicon, are obtained from uncommon and expensive elements, noted the project leader, leading expert at MISiS University and Professor Anvar Zakhidov.

Another important factor is that perovskite-based photoelectronics printing is not limited to printing on glass. This significantly reduces the cost of new batteries compared to older ones. in complex ways creating components from thin film. These perovskite components have active tiers. They can be applied without problems even to the most flexible and thin substrates. And modern roll technology makes it possible to place solar panels on surfaces of various curvatures. Taking into account all these advantages, the scope of application of innovative batteries is expanding and goes far beyond the use of traditional silicon analogues. The development can supply natural energy to portable electronic and household appliances, be implemented in the project " Smart House" etc. Perovskite-based batteries guarantee an uninterrupted supply of electrical energy to homes. The innovation is also suitable for the automotive industry.

Scientists around the world are working to create new solar cells that, while highly efficient, could take different forms and be widely used in construction in the construction industry. Each new development, each new achievement of scientists, each new generation of solar panels is a small but step forward, it is a kind of breakthrough in the development of alternative energy sources that will reduce humanity’s dependence on traditional fossil fuels.

The future of photovoltaics: three promising directions

1.Transparent solar panels

Australian company Dyesol is working on what it says is the photovoltaic system of the future. The basis of this system is the so-called “Gretzel cells” - multi-colored solar cells. They owe their name to the man who invented them, chemist Michael Gretzel, who patented these cells back in 1992. These cells function in a similar way to how the green leaves of plants function. The dye contained in the material of these cells reacts to light and thereby creates a potential difference on the surface of the film. Gretzel cells are almost transparent and can be used in a variety of coatings. This makes them flexible, and their scope of application is practically unlimited.

Multi-colored gretzel cells on the façade of the new Conference Center in Lausanne.

The biggest advantage of these cells is that they are cheap, environmentally friendly, and work even from scattered light and at unfavorable angles of incidence of sunlight. However, their full practical application requires additional research. The fact is that the efficiency of these cells does not yet exceed 15%, which is significantly lower than similar indicators for silicon helium cells. However, theoretical calculations show that with appropriate technologies, the efficiency of gretzel cells can reach 31%. And then in the very near future we can expect the appearance of houses whose walls are covered with paint that generates electricity.

2.Photovoltaics embodied in stone

The research laboratory of the German university from the city of Kassel, under the leadership of Professor Heike Klussmann, continuing the work begun by Gretzel, went much further in their research. The laboratory developed a building material that combines the properties of concrete and a helium cell.

This new material its creators called it DysCrete. As the researchers explain, concrete in this case acts as an electrode, while artificial photosynthesis occurs in dyes made from fruit extracts. At the very beginning, the research team even experimented with blackcurrant juice until the developers found more effective dyes.

Experiments with red dyes and concrete at the University of Kassel.

Project leader Professor Heike Klussmann says: “Our goal is to develop a material that will find wide application in the construction industry in the future, for example for prefabricated elements in the construction of buildings and structures, as façade elements, new wall components.”

3.Roll solar cells

Thin, flexible and very cheap. These are the characteristics of gel foil and gel paper. The German company Heliatek has released a film whose thickness is significantly less than a millimeter. This film maintains its electrical efficiency even in low light and high temperature conditions. Currently, serious research and experiments with gel paper are being carried out by the Technical University in Chemnitz.

Researchers are experimenting with paper-film solar modules.

With normal printing techniques, the photosensitive layer can be applied to the paper. At the same time, quite encouraging results have already been obtained in the university laboratories. Today we are talking about a voltage of 4 volts and an efficiency of 1.3%. But this is just the beginning of the work. Theoretical calculations show the achievement of an efficiency indicator comparable to that of silicon solar cells. 3PV (Printed Paper Photo Voltaics) - this is what scientists called their discovery.

A look into the future: nanostructures with variable refractive index

In the Dutch city of Eindhoven, at the AMOLF Institute for Photonics and Semiconductor Nanophysics, a laboratory led by Professor Jamie Gomez Rivas conducts research to improve the efficiency of solar cells.

These studies are based on the idea of ​​maximizing the luminous flux per unit area. To bring this idea to life, the researchers turned to what had already been “invented” by nature - the eyes of night moths. These natural light detectors perceive the slightest quanta of light, thanks to which insects see perfectly and orient themselves in pitch darkness. In the image and likeness of the eyes of a night moth, scientists tried to create an artificial structure that would work in a similar way.

As a result of numerous experiments and complex calculations, a multilayer nanostructure based on gallium phosphide was obtained. The scientists published the results of their research in the journal Advanced Materials. In the published material, Professor Jamie Gomez Rivas says: “For the first time, we have shown that our structures enable almost complete absorption of light flux.” In the layered structure of a moth's eye, the refractive index of light gradually changes from layer to layer and increases more than threefold before it reaches the optic nerve. The researchers achieved the same effect using their multilayer structure of tiny nanorods with variable length and thickness.

Nanostructures with variable refractive index

Thanks to these variable sizes of nanorods, a smooth, continuous change in refractive index is achieved, which maximizes the capture of light rays across the entire spectrum of wavelengths, and also minimizes the effect of reflection. Now, according to the researchers, the time has come for the transition from scientific research to practical application results obtained and development simple way applying new coatings to solar panels. If this succeeds, then by applying such an anti-reflective nanocoating, the efficiency of solar cells can be increased significantly. Professor Rivas, at the same time, even considers it possible to develop a coating that will allow the use of up to 99% of the incident light.

Taking into account the trend in the development of solar power engineering and the steady increase in the efficiency of helium photoconverters, scientists have made a fairly optimistic forecast for the use of solar energy. According to this forecast, in 2050, 27% of all electricity generated on the planet will be generated by solar power plants.

Ecology of consumption. Science and technology: Swiss physicists have demonstrated the operation of a new generation of solar cells that have record high efficiency and at the same time remain quite cheap compared to conventional solar cells.

Swiss physicists have demonstrated the operation of a new generation of solar cells that have record high efficiency and at the same time remain quite cheap compared to conventional solar cells.

Films made from an analogue of an unusual natural mineral helped physicists from Switzerland create the new kind cheap solar panels that convert a record 20% of sunlight into electricity, according to a paper published in the journal Nature.

“The best prototype perovskite solar cells use special materials that are very difficult to manufacture and purify. Their minimum cost is about 300 euros per gram of substance, which makes them impossible commercial use. By comparison, our substance, FDT, is easy to make and five times cheaper, yet has the same properties,” said Mohammad Nazeeruddin from the EPFL.

In recent years, scientists have created several exotic materials that can increase the efficiency of solar cells several times. In particular, the attention of physicists is increasingly attracted by the mineral perovskite and its synthetic analogues, thin films of which are semiconductors that are good at converting light energy into electricity.

Most light-absorbing materials have a symmetrical crystal structure, which allows electrons to flow freely in different directions. Perovskite has a cubic crystal lattice formed by atoms of a single metal. Inside each cube there is an octahedron formed by oxygen atoms, inside of which sits an atom of another metal.

The interaction between these atoms causes electrons to flow in the same direction, which is why perovskite solar cells have extremely high efficiency, about 12-15%. Naziruddin and his colleagues were able to achieve even more high level efficiency without increasing the cost of the battery by creating the FDT substance.

It falls into the category of so-called “hole carriers” - special substances that help remove positive charges, so-called “holes”, from the perovskite film after light particles enter it and “knock” electrons out of it. In terms of its chemical structure, FDT is a small aromatic hydrocarbon molecule, similar in shape to a butterfly with large wings.

The tips of the wings of this “butterfly” cling to the surface of the perovskite film, and its lower part interacts with the iodine atoms, which serve as a source of “holes” and electrons, and causes them to quickly return to their working position after light knocks the next electron out of the perovskite crystal.

Thanks to its unusual properties, a solar cell coated with a thin layer of FDT is capable of achieving a record efficiency to date - over 20.2%, which is slightly higher than solar cells based on more expensive “hole carriers”. Scientists hope that their discovery will bring us closer to the emergence of truly effective “green” energy sources. published

For many millennia, humanity has used natural resources to obtain energy. Starting with wood, which was burned to keep warm and cook food, and ending with nuclear energy. Earth's reserves turned out to be impermanent, and needs modern society incomparably high compared to renewal processes. The most promising direction in the search for alternative energy sources has become new solar panel technologies.

Brilliant invention

Already at the end of the 19th century. scientists began to think about using solar energy. The reason was the work of the famous French physicist A. Becquerel - “Electrical phenomena arising from the illumination of bodies.” In it, he described the photovoltaic effect - the occurrence of voltage or electric current in substances under the influence of light. An invaluable contribution was made in 1873 by the English electrical engineer W. Smith, who discovered the photoconductivity of selenium. In 1887, the German physicist Hertz discovered the external photoelectric effect by studying the release of electrons from a substance when exposed to light.

For more than half a century, scientists have been working on creating a direct light-to-electricity converter. In the 1950s Bell Laboratories specialists created the first full-fledged solar panel. New technologies immediately aroused great interest in the space sector and, after only 4 years, American and Soviet satellites equipped with solar panels were launched into space.

Solar Energy Today

It would seem, why build nuclear reactors when a little more than 8 light minutes away from us there is a thermonuclear source of colossal energy - the Sun. If we imagine the power of the photon flux in Watts, then on average, taking into account pole-equator, day-night and summer-winter, we get 325 W per 1 m². Considering the earth's surface area is 510.1 million km², it turns out that our planet constantly receives 165.7 trillion kW per hour.

In one day, as much energy comes from the Sun to the Earth as all the power plants in the world cannot produce in a year.

Conversion of light energy

Currently, the use of solar energy has become an urgent task. After all, this is the cheapest and most environmentally friendly way to generate electricity and heat. Compared to thermal power plants, the final price of electricity for the consumer is 80% cheaper. The need for alternative sources of inexpensive electricity has increased the demand for solar panels, and competition between manufacturers has stimulated the scientific development of new technologies.

There are 3 ways to convert light energy, which are already widely used around the world.

This is the easiest way using inexpensive equipment. The principle of operation is to heat water by the Sun. Until recently, such installations were used mainly only in hot countries for hot water supply. Modern collectors produced in Russia are designed for use in northern regions. When the outside temperature is 10°C in clear weather, they heat the water to 80-90°C.

Relatively new technology, which is being actively implemented in Germany. The plant was originally conceived to produce cheap hydrogen without harming the environment. Hydrogen itself is the most environmentally friendly fuel. Unlike hydrocarbons, the product of its combustion is ordinary water vapor (H 2 + 0.5 O 2 → H 2 O). During the development, an entire energy complex was obtained that could provide private households with electricity, hot water supply and heating. In good weather, electricity is generated by batteries, and excess energy is used to produce hydrogen. If there is a lack of generated electricity, the accumulated hydrogen is used. Leading manufacturers of such complex systems are HPS Home Power Solutions GmbH and CNX Construction.

The direct conversion of solar energy into electrical energy is constantly being improved and expanded. The rapid growth of SES implementation is confirmed by statistics. In 2005, the total capacity of solar projects was only 5 GW, and already in 2014 - 150 GW. Today there are many such power plants in the world, the largest of which are:

• Topaz, California - 1096 MW;
• Agua Caliente, Arizona - 626 MW;
• Mesquite, Arizona - 413 MW;
• Solar Ranch, California - 399 MW;
• Huanghe, Qinghai – 317 MW;
• Catalina, California - 204 MW;
• Xitieshan, Qinghai – 150 MW;
• Ningxia Qingyang, Ningxia – 150 MW;
• "Perovo", Crimea - 133 MW;
• "Silver", Nevada - 122 MW.

There are currently 23 solar power plants operating in Russia with a total capacity of 250.318 MW. In addition, the equipment used is constantly being modernized and capacity is being increased.

Currently, there are 31 solar power plants at the design and construction stage in the Russian Federation.

In addition to large-scale energy projects, solar panels are increasingly used in everyday life and in various types of devices. They are installed on the roofs of private houses, on street lighting poles, and built into portable charging device, computer equipment and autonomous lighting devices for the local area.

Among the most unusual solutions are a bicycle path in the Netherlands and a kilometer-long section of a road in France, made with a coating of photocells, and in Korea they have developed an implant battery. It is 15 times thinner than a hair, designed for implantation under the skin and is capable of powering implanted devices.

Operating principle

The light-receiving panel consists of cells (modules) that are made of a two-layer semiconductor material with photoconductivity properties. The top layer of the “n” type semiconductor has a negative potential, and the bottom layer of the “p” type has a positive potential. When light rays hit the top layer, an external photoelectric effect occurs. In other words, the semiconductor “n” begins to give up electrons. At the same time, the lower “p” layer, on the contrary, is capable of capturing electrons. Thus, if you close a circuit by connecting a load to the layers, the electrons that leave the top layer will flow through the load to the bottom layer. Then through p-n junction again return to the upper layer.

Real achievements

Many materials are used to create modules; according to laboratory studies, the most effective were multilayer solar cells of the GaInP/GaAs/Ge type, which showed a photoelectric conversion coefficient of 32%. At the same time, in reality, much higher record figures were set.

In 2013, Sharp created a three-layer solar cell based on indium gallium arsenide, which showed an efficiency result of 44.4%. Their record was surpassed in the same year by scientists from the Fraunhofer Institute for Solar Energy Systems. They used Fresnel lenses in the design of their photocell, which achieved an indicator of 44.7%. A year later, they outdid themselves and, thanks to special focusing, the lenses were able to achieve an efficiency of 46%.

Modern developments

One of the promising areas is the conversion of all radiation spectra into electricity. Developments in this direction are being carried out by many companies, institutes, research centers and the results are already there.

Nanoantenna theory

The idea of ​​converting solar radiation into electricity based on the principle of a rectifying antenna operating in the optical wavelength range of 0.4-1.6 microns, appeared back in 1972 and belongs to R. Bailey. The potential efficiency of such antennas in theory will be 85%. The first attempt to create a solar converter using nanoantennas was made in 2002 by ITN Energy Systems, which was unsuccessful. Despite this, this technique is considered the most promising and research continues.

Today this material, as an alternative to silicon, is the most popular among manufacturers. Its cost is much cheaper, which ultimately has a positive effect on the price of the product. Moreover, it contains toxic lead, which they have been trying to replace for a long time. A group of Dutch scientists, working on this issue, accidentally made a discovery.

Lead was replaced with tin and during test studies a strange phenomenon was noticed. “Hot electrons,” that is, electrons with increased energy, gave it away in a few nanoseconds, instead of several hundred femtoseconds, which is much longer. In conventional panels, such electrons are converted into heat rather than electricity. In this case, due to the slowness of electrons, it becomes possible to convert them into electricity before they become heat.

For now, scientists are figuring out why hot electrons slow down their scattering and how they can be made to scatter even more slowly. According to Professor of Photophysics and Optoelectronics M. Loi, theoretical predictions for the efficiency of such a battery will be 66%.

Ideal radiation

To solve the problem of a light element absorbing the entire spectrum of solar radiation, a team of researchers from Haifa (Israel) proposed a non-standard solution. In experiments, they decided to convert sunlight into ideal radiation. To do this, they developed and used a unique photoluminescent material. Similar technology is used in LED lamps, where the diode glow is absorbed by the phosphor and converted into a glow that is optimal for human perception. In the case of an element, the material converts the entire spectrum of radiation into light, which is ideally absorbed by the panel. According to young scientists, the transformation of light will increase the conversion into electricity by up to 50%.

Multilayer panels for roof installation

Previously, scientists from the University of New South Wales proposed concentrating solar radiation using mirrors. This technique made it possible to significantly increase the efficiency of the elements. Today this technology is used in many solar power plants, but for batteries installed on the roofs of private houses, such a design is impossible. The developers of the German scientific center Agora Energiewende proposed increasing the conversion efficiency of unconcentrated light to 53%.

Their invention is based on a multilayer panel capable of absorbing 4 ranges of light. A special refractive layer reflects the infrared spectrum to the silicon part and transmits the rest of the light to the three-layer panel. The first layer is indium gallium phosphide, the second is indium gallium arsenide and the third is germanium. Each absorbs light in a certain range, and as a result, it is possible to “squeeze out” the maximum energy.

The design is ideal in theory, but in practice, rooftop applications have encountered maintenance issues. Currently being developed for the private sector, the battery is more suitable for power plants, but work to improve it continues.

Energy day and night

The developments of Chinese scientists have attracted particular attention from many scientific publications. This is not surprising, since China is a leader in this area and is the largest supplier of solar panels, which are in demand around the world.

Chinese developers have proposed a panel that works not only during daylight hours, but also at night. The secret lies in a layer of phosphor with a long afterglow. During the day, the light not absorbed by the photocell is retained by the phosphor, which glows at night, releasing energy to the photocells. Although the nighttime efficiency is only 25%, such batteries can significantly improve the efficiency of solar energy.

Engineering solutions

With the growth of SES around the world, new problem, especially relevant for European countries. To build such power plants, a large space is required. To some extent, this problem is solved by integrating photocells into the road surface and installing light receivers on roofs. But often it is necessary to modernize roofing structures, and in some cases the installation contradicts architectural features. The urgency of increasing the integration capabilities of solar panels has become critical, so leading engineers and architects are working on this today.

Roofing made of photocells

Hanergy presented an interesting design at the Solar Power International 2017 conference in Las Vegas. Hantiles roofing tiles are wave-shaped tiles with built-in photovoltaic cells. By combining roofing material and photocells, the aesthetic appearance of the building is preserved, and the roofing structure does not require additions. In addition, the cost is cheaper than purchasing the roof and panels separately.

Wall cladding with solar panels

The Swiss Center for Microtechnology and Electronics “CSEM” has proposed a new technology for the production of external wall cladding panels, which are also solar panels. The peculiarity lies in maintaining the qualities of the facing material. The panels look monotonous and have high heat and sound insulation properties. So far, only white options have been presented, but the developers say that any color is possible.

Soon, instead of energy-saving windows, it will be possible to install energy-generating windows. The innovative window from the developers of the Los Alamos National Laboratory is visually no different from simple windows. At the same time, they use a single-chamber glass unit with built-in manganese-based quantum dots on external glass and based on copper-indium selenide on the internal. The glass acts as a luminescent concentrator and, absorbing light, redirects it to the edges of the frame, where it is converted into electricity by built-in photocells.

German engineers from the University of Jena went even further. They offered smart windows. The idea of ​​smart windows is not new. Previously, other developers proposed glass that changed translucency and generated electricity through laminated photocells. This time a fundamentally new LaWin technology was used. Now the functions of windows have been added to the ability to work as lighting and heating.

Charge on the go

Japanese developers from the RIKEN Institute and the University of Tokyo have invented an ultra-thin flexible solar cell that is not afraid of water and tensile loads. By integrating such a battery into textiles, it is possible to create connected clothing mobile devices or any other electronics.