Interpretation of solar panel related knowledge
Jan 17, 2019

Interpretation of solar panel related knowledge

First, the principle of solar cell power generation: Solar cells are a pair of devices that respond to light and convert light energy into electricity. There are many kinds of materials that can produce photovoltaic effect, such as: monocrystalline silicon, polycrystalline silicon, amorphous silicon, gallium arsenide, and the like. Their power generation principle is basically the same, and the crystal power generation process is now described by taking a crystal as an example. The p-type crystalline silicon is doped with phosphorus to obtain N-type silicon to form a P-N junction. When the light illuminates the surface of the solar cell, part of the photons are absorbed by the silicon material; the energy of the photons is transferred to the silicon atoms, causing the electrons to move more and more, and the free electron PN junctions are concentrated on both sides to form a potential difference when the circuit is externally connected. Under the action of this voltage, there will be a current flowing through the external circuit to generate a certain output power. The essence of this process is the process of converting photon energy into electrical energy.

Second, there is no difference between polycrystalline silicon solar cells and electrocrystalline silicon solar cells. The life and stability of polycrystalline silicon solar cells and monocrystalline silicon solar cells are very good. Although the average conversion efficiency of monocrystalline silicon solar cells is about 1% higher than the average conversion efficiency of polycrystalline silicon solar cells, since monocrystalline silicon solar cells can only be made into quasi-squares (four tops are arcs), when composing solar cell modules When a part of the area is filled, and the polycrystalline silicon solar cell is square, there is no such problem, so the efficiency of the solar cell module is the same.

In addition, since the manufacturing process of the two solar cell materials is different, the energy consumed in the manufacturing process of the polycrystalline silicon solar cell is about 30% less than that of the monocrystalline silicon solar cell.

The single crystal silicon battery has high battery conversion efficiency and good stability, but the cost is high. Monocrystalline silicon cells have broken through the technical barrier of over 20% photoelectric conversion efficiency more than 20 years ago.

Polycrystalline silicon cells have low cost and low conversion efficiency. Straight-drawing single crystal silicon solar cells, various defects in materials such as grain boundaries, dislocations, micro-defects and impurities in materials, carbon and oxygen, and transitional groups in the process of contamination Metal is considered to be the gateway that has caused the photoelectric conversion rate of polycrystalline silicon cells to be unable to break by 20%.

From the point of solid physics, silicon is not the most ideal photovoltaic material. This is mainly because silicon is a simple semiconductor material with low light absorption coefficient, so research on other photovoltaic materials has become a trend. Among them, cadmium telluride (CdTe) is recognized as two very promising photovoltaic materials, and has made some progress, but it requires a lot of work to do from large-scale production and to compete with crystalline silicon solar cells.

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