Solar panel is a device that absorbs sunlight and converts solar radiation energy directly or indirectly into electricity through photoelectric effect or photochemical effect. The main material of most solar panels is "silicon", but its widespread use is limited due to its high production cost.
At present, crystalline silicon materials (including polysilicon and monocrystalline silicon) are the most important photovoltaic materials, accounting for more than 90% of the market, and will still be the mainstream material of solar cells for a long time in the future.
Monocrystalline silicon
Monocrystalline silicon solar cells have an average photovoltaic conversion efficiency of around 18 percent and a maximum of around 25 percent, which is the most efficient of all solar cells, but the cost of making it is so high that it is not yet widely used. Because monocrine silicon is usually encapsulated in toughened glass and waterproof resin, it is strong and durable, with a service life of up to 25 years.
polysilicon
The production process of polycrystalline silicon solar cells is similar to that of monocrystalline silicon solar cells, but the photoelectric conversion efficiency of polycrystalline silicon solar cells is much lower, its photoelectric conversion efficiency is about 16%. In terms of production cost, it is cheaper than monocrystalline silicon solar cells, the material is simple to manufacture, saves power consumption, and the total production cost is low, so it has been developed in large quantities. In addition, the service life of polysilicon solar cells is shorter than that of monocrystalline solar cells. In terms of performance-price ratio, monocrystalline silicon solar cells are slightly better.
Amorphous silicon
Amorphous silicon solar cell is a new type of thin film solar cell appeared in 1976, it is completely different from monocrystalline silicon and polycrystalline silicon solar cell production method, greatly simplified process, silicon material consumption is less, lower power consumption, its main advantage is that it can also generate electricity under weak light conditions. However, the main problem of amorphous silicon solar cells is that the photoelectric conversion efficiency is low, the international advanced level is about 10%, and it is not stable. With the extension of time, its conversion efficiency decreases.
Polycompound
Polycompound solar cells are solar cells that are not made of a single element semiconductor material. A) Cadmium sulfide solar cells b) Gallium arsenide solar cells c) Copper indium selenium solar cells (novel multi-band gap gradient Cu(In, Ga)Se2 thin film solar cells)
Cu(In, Ga)Se2 is a kind of solar energy absorbing material with excellent performance, which has multiple gradient band gap (energy level difference between conduction band and valence band). It can enlarge the solar energy absorption spectrum and improve the photoelectric conversion efficiency. Based on it, the photoelectric conversion efficiency of thin film solar cells can be significantly higher than that of silicon thin film solar cells. In addition, no radiation induced performance degradation effect (SWE) has been found in this kind of thin film solar cells. The photoelectric conversion efficiency of this kind of thin film solar cells is about 50-75% higher than that of commercial thin film solar panels, which is the highest level of photoelectric conversion efficiency in the world.
