Views: 0 Author: Site Editor Publish Time: 2023-09-23 Origin: Site
Green and low-carbon is an important development goal during my country’s “14th Five-Year Plan” period, Photovoltaic power generation is the main force to achieve this goal. In the process of rapid development of the photovoltaic industry, In addition to crystalline silicon cells attracting much attention, Thin-film batteries using cadmium telluride as the absorber layer have also attracted industry attention.
Cadmium telluride power generation glass is a low-carbon, green, energy-saving, energy-creating, environmentally friendly and safe new energy and new material, It is both a green building material and a clean energy source, It has the typical characteristics of architectural glass, Beautiful and elegant, various styles, Low light power generation, Empowering buildings, Make the earth more beautiful, It is the choice to help achieve the goals of "carbon peak" and "carbon neutrality".
Cadmium telluride (CdTe) is an important II-VI compound semiconductor material, The shape is black crystal particles or powder, The melting point reaches 1092℃, Relative molecular weight 240, The crystal structure is sphalerite type, It has a direct transition energy band structure. Its lattice constant is 0.6481nm, The bandgap width is 1.45eV, Room temperature electron mobility is 1050 c㎡/(Vs), The room temperature hole mobility was 80 c㎡/(Vs).
The bond energy of the chemical bond of cadmium telluride is as high as 5.7eV, It is one of the most stable chemosynthetic states of the element cadmium in nature. Therefore, cadmium telluride is chemically stable at room temperature, and insoluble in water, weak acids, It is relatively safe during industrial production and use.
It is worth mentioning that, The spectral response of cadmium telluride solar cells closely matches the terrestrial solar spectral distribution, The actual power generation capacity is strong.
Cadmium telluride has stable performance, High light energy absorption coefficient, N-type or P-type semiconductor materials can be obtained by doping different impurities, It can be used in the manufacture of nuclear radiation detectors (for medical use), infrared electro-optical modulators, infrared detectors, infrared lenses and windows and other devices. In the photovoltaic field, Cadmium telluride is regarded as a key raw material for the preparation of large-size solar thin film cells. A cadmium telluride film with a thickness of only 2μm (micron), The optical absorption rate exceeds 90% under standard AM1.5 conditions, The theoretical conversion efficiency is as high as 33%, Therefore, solar energy has become a relatively large application field for cadmium telluride. Normally, the photovoltaic industry requires the use of cadmium telluride with a purity of 5N.
Compared with other solar cells, The structure of cadmium telluride thin film solar cells is relatively simple; Generally speaking, The traditional structure consists of five floors, That is, glass substrate, transparent conductive oxide layer (TCO layer), cadmium sulfide (CdS) window layer, cadmium telluride (CdTe) absorption layer, back contact layer and back electrode, As shown in the figure below.
As the domestic policy system for building energy conservation gradually improves, The government's emphasis on building energy efficiency has increased significantly. If dual-carbon targets are to be met, It is inseparable from the important path of building integrated photovoltaics (BIPV).
2020, China's Ministry of Housing and Construction and seven other ministries and commissions have issued action programmes related to green building, The plan aims to account for 70% of new green buildings in 2022, It is required to guide government investment projects to take the lead in using green building materials. Cadmium telluride power generation glass building materials prepared through cadmium telluride thin film battery technology, It is a new generation of green building materials.
Compared with crystalline silicon components, Cadmium telluride thin film modules have the characteristics of high absorption coefficient, small hot spot effect, good low-light effect, high aesthetics, and strong customization,
It can be flexibly applied to various building structures such as building roofs and curtain walls,Increasing the effective power generation area by making relatively large use of the building's surface, Meet multi-angle building power generation needs, Ultimately reducing building carbon emissions from the source. Driven by favorable policies, The demand for cadmium telluride thin film photovoltaic modules will further expand in the future.