Canada has developed a full-spectrum solar cell with 42% conversion efficiency

According to a report from the American Physicists Organization Network on June 27 (Beijing time), Canadian scientists said that they have developed a new type of full-spectrum solar cell that not only absorbs visible light from the sun but also absorbs invisible light. In theory, the conversion efficiency can be as high as 42%, which exceeds the theoretical conversion rate of 31% of existing ordinary solar cells. The study was published in the latest issue of the journal Nature Photonics. This highly efficient tandem solar cell based on colloidal quantum dots (CQDs) was developed by Canada’s leading nanotechnology scientist and a team led by Ted Sargent, professor of the Department of Electronics and Computer Engineering at the University of Toronto. The main author of the paper, Wang Xihua, stated that the solar cell consists of two light-absorbing layers: one layer is modulated to capture the visible light emitted by the sun; the other layer can capture the invisible light emitted by the sun. Sargent said that in order to achieve this, the team used nanomaterials in series to form a device called a hierarchical recombination layer, capable of transporting electrons between the visible light layer and the invisible light layer to and fro, effectively capturing the light-absorbing layer of visible light. In combination with the light-absorbing layer that captures invisible light, both light-absorbing layers need not be compromised. The research team took the lead in manufacturing solar cells using CQD, a nanomaterial that can be easily modulated to respond to visible and invisible light at specific wavelengths. The new series CQD solar cell captures the wavelength range of light waves more widely than ordinary solar cells. Therefore, in theory, the conversion rate can reach 42%; in contrast, the maximum conversion rate of the best single-junction solar cells is only 31%, and the conversion rate of solar cells, which are usually located on the roof or in daily consumer products, is only 18%. The development of high-efficiency, cost-effective solar cells is a common global challenge. Sargent said: “Globally, solar cells with conversion efficiencies of more than 10% are needed, and we hope to significantly reduce the retail price of existing PV modules. The latest development provides a practical way to capture the maximum possible solar emission. Various lights are expected to increase conversion rates and reduce costs." Sargent hopes to integrate this new graded, reconstituted solar cell into building materials, cell phones and automotive parts within five years. Compared with some repeated emphasis on capturing ultra-high “light energy”, the Canadian scientists’ technology is obviously more forceful than the research on conversion rate. As of the end of 2010, the global installed total solar energy is about 40 GW. This is roughly equivalent to the full-load operation of the two Three Gorges Hydropower Stations. At present, the conversion rate of solar energy products on the market is generally lower than 18%, and it is not difficult to calculate. If this value can be increased to 20%, 30% or even 42%, the commercial value behind it and its significance for mitigating the energy crisis will be significant. . This also shows that once the experimental data comes out of the laboratory, it may become benefits, opportunities, and even hope that, in any case, is no longer a simple number. The newspaper (Reporter Liu Xia)