Solar power generation because of its clean, pollution-free, almost never exhausted advantages, become the best alternative to fossil energy. Countries around the world attach great importance to this, vigorously carry out relevant science and technology and product research, has formed a huge industry, and will play a very important role in the "carbon peak, carbon neutral" major strategy. So in addition to the common monocrystalline silicon, polysilicon and other silicon-based solar cells in the current market, what other new solar cells do you know? Let's talk about that today.
The U.S. Department of Energy's National Renewable Energy Laboratory, or NREL, tracks scientific and technological advances in new solar cells around the world, The world record of research solar cell photoelectric conversion efficiency since 1976 and solar cell module photoelectric conversion efficiency since 1988 are recorded, as shown in the figure below.
As can be seen from the figure, there are 26 kinds of research solar cell technology routes tracked by NREL, and 19 kinds of routes that can be made into modules for efficiency testing and obtained records. Most of the technology routes are still under development, and some may mature to market in the near future. These technical routes are divided into several categories to introduce respectively.
1 Silicon-based solar cells
There are six research solar cell technology routes using silicon as the main photoelectric conversion material. In addition to monocrystalline silicon and polycrystalline silicon solar cells, there are concentrating monocrystalline silicon, silicon-based heterojunction (HIT), thin film crystalline silicon and thin film amorphous silicon (amorphous silicon) solar cells. The most efficient single junction cell is concentrating monocrystalline silicon solar cell, which can reach 27.6%.
There are 9 kinds of solar module technology routes which take silicon as the main photoelectric conversion material. In addition to PERC and IBC which we are usually familiar with, there are also polycrystalline silicon, single heterojunction IBC, thin film silicon, amorphous silicon, double junction silicon, triple junction silicon and other silicon routes. The most efficient single junction cell is single heterojunction IBC solar cell, which can reach 24.4%.
Polycompound solar cells
Solar cells on the satellite
Multi-compound solar cells are solar cells which are composed of compound semiconductors formed by two or more elements as photoelectric conversion materials. The research solar cells mainly recorded in GaAs (Gallium arsenide), CIGS (copper indium gallium Selenium), CdTe(cadmium telluride), CZTSSe (copper zinc tin sulfur/selenium) solar cells. The single junction efficiency of GaAs solar cell is the highest, which can reach 35.5% under concentrating condition, and 29.1% under non-concentrating condition.
As for the cell components, GaAs solar cells have the highest efficiency of single junction cells, which can reach 25.1%. GaAs solar cells were early chosen for use in satellites due to their high photoelectric conversion efficiency.
Dye-sensitized solar cells
Dye-sensitized solar cells are a new type of solar cells developed in the early 1990s, which use semiconductor materials as electron transport layer and synthetic dyes as light absorption materials. This type of solar cell has been highly regarded by researchers at the beginning of the rise, as the "third generation" solar cell, once formed a worldwide research upsurge. At present, the highest conversion efficiency of this type of solar cell in the laboratory is 13.0%, and there is no component efficiency record on the list. There is still a certain gap from practical application, and only a few products are put into trial in some special application scenarios.
Organic solar cells
Organic solar cell is a new type of solar cell, which mainly uses artificial organic donor and acceptor molecules as photoelectric conversion materials. The biggest advantage of organic solar cells is that they can be made into flexible, flexible and flexible solar cells, and are relatively easy to mass produce roll-to-roll. The maximum efficiency of this type of research solar cell can reach 18.2%, and the module efficiency can reach 11.7%, which has certain application prospects, especially in some application scenarios requiring special shapes.
5 Perovskite solar cells
Perovskite solar cell is a new type of solar cell developed on the basis of dye-sensitized solar cell. At first, artificial perovskite material replaced dye as the light absorption layer, and then gradually abandoned part of dye-sensitized solar cell and developed into an independent type. This kind of solar cell has only been produced for more than 10 years, but the efficiency of its research solar cell has reached 25.5%, the module efficiency has reached 17.9%, which has become a super research hotspot worldwide. At present, several enterprises at home and abroad have started to build megawatt perovskite solar cell production line. Become the most promising new solar cells to enter the market.
Quantum dot solar cells
Quantum dot solar cells are developed on the basis of dye-sensitized solar cells. Quantum dots with different sizes and light absorption properties are used as photoelectric conversion materials. The research efficiency of quantum dot solar cells currently reaches 18.1%. No component efficiency has been listed and is still being studied.
7 Multi-junction solar cell
In order to make full use of different wavelengths of sunlight and further improve photoelectric conversion efficiency, researchers stacked solar cells with different light absorption bands in series to form a multi-junction solar cell. At present, the highest number of knots tracked by the effective record is 4 knots, and the research efficiency can reach 47.1% under concentrating condition and 39.2% under non-concentrating condition. The component efficiency can reach 40.6% under concentrating condition and 31.2% under non-concentrating condition.
In general, the current solar cell market is still based on silicon, and this situation will continue for a long time. As the technology matures, new types of solar cells will enter the market independently or in combination with silicon-based cells. Let's see!