When incoming radiation comes only from an area of the sky the size of the Sun, the efficiency limit is reduced to 68.7%. The National Renewable Energy Laboratory (NREL) of the Department of Energy created a solar cell with a record efficiency of 39.5% under global lighting of 1 Sun. . The details of the development are described in the article “Triple-junction solar cells with a terrestrial efficiency of 39.5% and a space efficiency of 34.2% thanks to thick supergrids of quantum wells”, which appears in the May issue of the magazine Joule.
The improvement in efficiency came after research on “quantum well” solar cells, which use many very thin layers to modify the properties of solar cells. The scientists developed a quantum well solar cell with unprecedented performance and implemented it in a device with three junctions with different band intervals, in which each junction is adjusted to capture and use a different portion of the solar spectrum. III-V materials, named after their location on the periodic table, cover a wide range of energy bands that allow them to target different parts of the solar spectrum. The upper junction is made of indium gallium phosphide (GaInP), the central part of gallium arsenide (GaAs) with quantum wells, and the lower part of indium gallium arsenide (GaAs) that does not match the network.
Each material has been highly optimized through decades of research. The scientists used quantum wells in the middle layer to extend the GaAs cell's band interval and increase the amount of light the cell can absorb. It is important to note that they developed optically thick quantum well devices without large voltage losses. They also learned how to anneal the upper GainP cell during the growth process to improve its performance and how to minimize threaded displacement density in GAINAs that do not match the network, which is discussed in separate publications.
Together, these three materials serve as the basis for the new cell design. III-V cells are known for their high efficiency, but the manufacturing process has traditionally been expensive. Until now, III-V cells have been used to power applications such as space satellites, unmanned aerial vehicles and other specific applications. NREL researchers have been working to dramatically reduce the cost of manufacturing III-V cells and provide alternative cell designs, making these cells economical for a variety of new applications.
The new III-V cell was also tested for efficiency in space applications, especially in communications satellites, which operate with solar cells and for which high cell efficiency is crucial, and obtained 34.2% to measure the beginning of its useful life. The present cell design is suitable for low radiation environments, and higher radiation applications can be made possible by further development of cellular structure. In the past two years, there has been an increase in the number of manufacturers that have launched more efficient solar panels based on high-performance N-type heterojunction cells (HJT). However, high-efficiency panels that use N-type cells almost always outperform and last longer than panels that use P-type cells due to the lower light-induced degradation rate (LID), so the additional cost is often worth it in the long run.
As explained above, the most efficient standard-size panels use high-performance N-type or back-contact IBC cells that can achieve panel efficiency of up to 22.8% and generate an impressive amount of 390 to 440 watts. We examined and highlighted what makes the LG Neon 2, Neon R and the new Neon H panels stand out from the crowd in performance, reliability and efficiency. Panels made with high-cost IBC cells are currently the most efficient (between 20 and 22%) thanks to the high-purity N-type silicon substrate and the absence of losses due to the shading of the busbar. To reduce manufacturing costs, increase efficiency and increase energy, solar panel manufacturers have moved away from the standard size of 156 mm square-cell wafers (6) in favor of larger wafer sizes.
For example, this shows that perovskites can be used to build very efficient photodetectors and, in the future, perhaps solar cells. The most efficient solar panels on the market generally use highly efficient N-type monocrystalline silicon cells (IBC) or the other highly efficient N-type variation heterojunction cells (HJT). We review the latest range of Deep Blue 3.0 panels, which have the latest photovoltaic cell technology to increase efficiency and durability. Hyundai, a large solar panel manufacturer based in South Korea, offering a range of high-end panels based on exclusive tile cell technology.
Cell efficiency is calculated using what is known as the fill factor (FF), which is the maximum conversion efficiency of a photovoltaic cell to the optimal operating voltage and current. Increasing the size of the panel can also increase efficiency, as a larger surface area is created to capture sunlight. The most powerful solar panels now reach a nominal power of up to 700 W. We analyze the best quality solar panels from the world's leading manufacturers: SunPower, REC, Panasonic, Q cells, Trina, Longi and Winaico, among others, that offer the highest performance, efficiency, best guarantees and reliability proven according to independent tests carried out by PVEL.
Trina Solar's latest range of Vertex panels is very efficient and affordable, making the price difference between well-known premium brands more difficult to justify. It would be fantastic if perovskites showed this effect to a remarkable degree that would make it possible to further increase the efficiency of solar cells. .