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Solar Panels The Ability Of Photons To Be Absorbed By The Medium

Jun 14, 2017

Solar Panels power as the field of clean energy "leader" is currently the industry's attention. If you are interested in this, take you to understand the composition of Solar Panels cells and related photovoltaic materials.

A Solar Panels power plant, commonly referred to as a Solar Panels cell, can convert Solar Panels energy directly into electrical energy. In Solar Panels panels, the sun's released photons make the outer electrons of the semiconductor material separate from the bond of the atomic bonds. When the electrons are forced to move in the same direction, they can generate electricity, power the electrical equipment, or power the grid.

Since the French physicist Alexandre-Edmond Bequerel in 1839 for the first time the photovoltaic power generation technology theory so far, photovoltaic power generation has been one of the themes of scientific research. At present, with the United States, Japan and Europe, the main research team to accelerate the industrialization of their respective Solar Panels energy systems, photovoltaic industry, the international market continues to expand.

PV modules

Although the composition of the photovoltaic power generation system is different, but all the components include several layers from the smooth to the back surface of the material. The sun first passes through the protective layer (usually glass) and then enters the interior of the battery through the transparent contact layer. In the center of the component is the adsorption material, this layer of material absorbs photons, and then complete the "photogenerated current." And the semiconductor material therein depends on the specific requirements of the photovoltaic system.

Below the adsorbent layer material is the back metal layer that completes the circuit conduction. Composite film layer in the back metal layer below, its role is to make the PV module waterproof adiabatic. Usually the back of the PV module will add an additional protective layer, the protective layer of materials for the glass, aluminum or plastic.

Semiconductor material

The semiconductor material in the photovoltaic power generation system may be a silicon, a polycrystalline thin film or a single crystal thin film. Silicon materials include monocrystalline silicon, polysilicon, and amorphous silicon. Monocrystalline silicon has a regular structure, which is higher than the polysilicon photoelectric conversion rate.

The silicon atoms in amorphous silicon are randomly distributed and have a lower photoelectric conversion rate than monocrystalline silicon, but it captures more photons than crystalline silicon while adding germanium or carbon to amorphous silicon Alloying can enhance this characteristic.

Copper indium diselenide (CIS), cadmium telluride (CdTe) and thin film silicon are commonly used in polycrystalline thin film materials, and photoelectric conversion rate of high materials such as gallium arsenide (gallium arsenide, GaAs) Also typically contain monocrystalline silicon thin film materials. The above materials are used in specific photovoltaic power generation areas because of their unique properties. These features include: crystallinity, band gap size, absorption performance and ease of processing.

The Influence of External Factors on

The order of the atomic arrangement in the crystal structure determines the crystallinity of the semiconductor material, and the charge transfer, current density and energy conversion efficiency of the Solar Panels cell are affected by the crystallinity. The bandgap of a semiconductor material is the minimum energy required to transition electrons from a restrained state to a free state (i.e., to allow electron conduction). The bandgap size is usually expressed in Eg, which describes the energy difference between the valence band and the conduction band. The price band of the semiconductor material is a low energy level, and the conduction band is a high energy level. The absorption coefficient is used to characterize the distance of the photon penetrating medium at a particular wavelength, which determines the ability of the photon to be absorbed by the medium. The absorption coefficient is determined by the wavelength of the battery material and the absorbed photon.

The cost and ease of processing of various semiconductor materials and devices depend on a variety of factors, including the type of material and the scale of use, the production cycle, and the migration characteristics of the battery in the deposition chamber. In the specific needs of photovoltaic power generation, each factor will play an important role.