The above discussions show that as materials for solar cells, III-V compounds and CIS are prepared from rare elements, although the conversion efficiency of solar cells made from these is very high, judging by. being the source of the materials, it is unlikely that this type of solar cells will dominate in the future. The other two types of batteries, nanocrystalline solar cells and polymer-modified electrode solar cells, have problems. Their research has just begun, the technology is not very mature, and the conversion efficiency is still relatively low. at the exploratory stage and will not be used in a short period of time. A possible alternative should be solar cells. Therefore, from the perspective of conversion efficiency and material sources, future development will remain focused on silicon solar cells, especiallyer thin film cells of polycrystalline silicon and amorphous silicon. Since polycrystalline silicon and amorphous silicon thin film cells have high conversion efficiency and relatively low cost, they will eventually replace monocrystalline silicon cells and become the leading products in the market.
Improving conversion efficiency and reducing costs are the two main factors considered in the preparation of solar cells. For silicon-based solar cells, it is difficult to further improve the conversion efficiency. Therefore, future research should focus on how to reduce costs while continuing to develop new battery materials. Existing high conversion efficiency solar cells are manufactured on high-quality silicon wafers, which is the most efficient way to manufactureer silicon solar cells. The expensive part. It is therefore particularly important to reduce the cost of the substrate while ensuring that the conversion efficiency remains high. This is also an urgent problem that needs to be solved in the future development of solar cells. Some technologies have been used abroad to produce silicon strips as substrates for polycrystalline silicon thin-film solar cells to reduce costs, and the results are quite satisfactory.
What are the classifications of solar cells?
HIT is called heterojunction battery in Chinese, and the full name is "crystalline silicon heterojunction solar cell". It deposits a thin layer of amorphous silicon on crystalline silicon and combines crystalline silicon batteries and thin film batteries. This advantage constitutes one of the important directions of the developmentment of silicon-based solar cells with high conversion efficiency.
Heterojunction cells have the advantages of short process flow, few steps, and lack of light-induced attenuation. They have high photoelectric conversion efficiency, excellent performance, large cost reduction margin, and good prospects for affordable Internet access. They are recognized by the industry as the technical solutions of the future. (See the latest report from China Energy Network)
In recent years, the construction of heterojunction battery production capacity in China has significantly accelerated. According to statistics, the planned national heterojunction generation capacity is 24.5 GW, of which approximately 1.07. GW was built. According to the new version of the International Photovoltaic Technology Roadmap (ITRPV), the market share of HIT will increase from 3% in 2018 to 10% in 2025, and is expected to reach 28% in 2028.
Is the crystalline silicon used in solar cells transparent?
According to the different materials used, solar cells can be divided into: silicon solar cells, multi-compound thin-film solar cells, polymer multi-layer modified electrode solar cells, nanocrystalline solar cells, solar cells Organic, plastic solar cells, whichSilicon solar cells are the most mature and dominant applications.
Silicon solar power
Silicon solar cells are divided into three types: monocrystalline silicon solar cells, polycrystalline silicon thin-film solar cells and polycrystalline silicon solar cells. thin layers of amorphous silicon.
Monocrystalline silicon solar cells have the highest conversion efficiency and technologythe most mature. The highest laboratory conversion efficiency is 24.7% and the large-scale production efficiency is 15% (in 2011 it was 18%). It still occupies a dominant position in large-scale applications and industrial production. However, due to the high cost and price of monocrystalline silicon, it is difficult to greatly reduce its cost in order to save silicon materials, polycrystalline silicon films and amorphous silicon. films have been developed as alternative monocrystalline silicon products.
Compared to monocrystalline silicon, polycrystalline silicon thin-film solar cells are cheaper and more efficient than amorphous silicon thin-film cells. The maximum conversion efficiency in the laboratory is 18%, and the conversion efficiency in industrial-scale production is 18%. 10% (in 2011 it was 17%). Consequentlyent, polycrystalline silicon thin-film cells will soon dominate the solar cell market.
Amorphous silicon thin film solar cells have low cost, light weight, high conversion efficiency, easy mass production and great potential. However, due to the photoelectric efficiency degradation effect caused by its material, its stability is not high, which directly affects its practical application. If the stability problem and the conversion rate problem can be further solved, then amorphous silicon solar cells will undoubtedly be one of the main development products of solar cells.
Polycrystalline thin film
Polycrystalline thin film cells such as cadmium sulfide and cadmium telluride have higher efficiency than amorphous silicon thin film solar cells and a lower cost thanmonocrystalline silicon cells, and are easy to use. produce on a large scale, but because cadmium is very toxic and can cause serious environmental pollution, it is not the most ideal substitute for crystalline silicon solar cells.
Nanocrystalline
Nanocrystalline chemical energy solar cells are a recently developed product. Its advantages lie in low cost, simple process and stable performance. Its photoelectric efficiency is stable at more than 10%, and its production cost is only 1/5 to 1/10 of that of silicon solar cells. The lifespan can reach more than 20 years.
The research and development of this type of battery has just started and will gradually enter the market in the near future.
Organic thin film
Organic thin film solar cells are solar cells whose core is composed of materialsorganic. It makes sense that not everyone is familiar with organic solar cells. More than 95% of solar cells mass-produced today are silicon-based, while the remaining less than 5% are also made of other inorganic materials.
Dye sensitization
Dye-sensitized solar cells attach pigment to TiO2 particles, then soak them in an electrolyte. The pigment is exposed to light and generates free electrons and holes. The free electrons are absorbed by TiO2, flow from the electrode to the external circuit, then pass through the electrical device, flow into the electrolyte and finally return to the pigment. Dye-sensitized solar cells are inexpensive to manufacture, making it very competitive. Its energy conversion efficiency is around 12%.
Plastic batteries
Plastic solar cells are fabricked from recyclable plastic films and can be mass-produced using “roll-to-roll printing” technology. They are inexpensive and environmentally friendly. . However, plastic solar cells are not yet mature. It is expected that in the next 5 to 10 years, solar cell manufacturing technology based on organic materials such as plastics will mature and be used on a large scale.
As long as it is silicon, it is opaque, whether it is polycrystalline silicon or monocrystalline silicon. I major in microelectronics and have seen silicon crystals in the lab.
But many silicon compounds are transparent, like crystal, namely SiO2.
The principle of solar cells is based on silicon. This semiconductor material has photothermal, magnetoelectric and other properties. Light is a meansto excite carriers.
However, in order to protect the solar cells and not affect their electricity production efficiency, the surface of the cells will be covered with a transparent protective layer, similar to that of our screensavers for cell phones~