Solar photovoltaic is mainly divided into two types: crystalline silicon and amorphous silicon
Crystalline silicon mainly includes: ingots (crystalline silicon rods) - wafers - photovoltaic cells - photovoltaic modules - systems Installation and equipment and raw materials materials related to these industries
Amorphous silicon (thin film) mainly includes: component preparation - system installation and equipment and materials raw materials related to these industries
Crystalline silicon Compared to thin films, the main advantages: high conversion efficiency. Disadvantages: many associated links and high cost.
Compared to crystalline silicon, main advantages of thin films: good low light effect (performance under low irradiation). Disadvantages: Equipment Cost is). too high and the conversion efficiency is too low
What is the main cost of thin film solar
The lowest photovoltaic solar power generation is thin film solar panel, its efficiency is generally about 8% to 10%, such as monocrystalline or polycrystalline silicon electrical panels, generally around 15% to 25%. High efficiency batteries such as gallium arsenide can reach around 30%. The efficiency of solid-state thermoelectric power generation is relatively low, currently generally below 10%.
The main reason for the high cost of thin film solar cells is that the production equipment has high technological content, the production process is complex, and the production capacity is not sufficient. did not follow. at the same time, the low material cost of thin-film solar cells and the automation of the production process have reduced the overall cost. For realTo understand the cost of solar cells, we still need to have a thorough understanding of the principles of electricity generation and production processes.
The current thin-film solar cells in the world are basically divided into four types: amorphous silicon thin-film cells, copper indium gallium thin-film cells (CIGS) , thin film cells of cadmium telluride (CdTe). film cells and gallium arsenide thin film cells.
1. Amorphous silicon solar panel
Amorphous silicon (a-Si) solar cells deposit a transparent conductive film (TCO) on a glass substrate, then three P-type layers. , a-Si i-type and n-type are deposited by plasma reaction, then the aluminum from the metal electrode (Al) is evaporated. The incident light comes from the glass surface and the battery current is drawn from the transparent conductive film et. aluminum. Its structure can be expressed as For glass/TCO/pine/Al, stainless steel sheets, plastics, etc. can also be used as substrates. The conversion efficiency of amorphous silicon is generally 5-10%.
Amorphous silicon solar cells use fewer materials, save energy and have a low cost; they have good low light effect and their short wave response is better than crystalline silicon solar cells; they have low temperature coefficients; Amorphous silicon cell components are damaged due to shading. The power reduction is much better than that of crystalline silicon; the appearance has good consistency and is suitable for architectural use without affecting the beauty of the building.
However, the current efficiency of amorphous silicon components is much lower than that of crystal silicon componentslinen. The efficiency of amorphous silicon generally does not exceed 10%. When constructing large-scale photovoltaic power plants, the required floor. The surface area will be larger than that of crystalline silicon, which is relatively impractical. Suitable for areas with strict floor space requirements.
2. Copper-indium-gallium-selenide (CIGS) battery panel
Copper-indium-gallium-selenide (CIGS) thin film solar cell is made of Cu (copper), In (indium) , Ga (gallium) ), Se (selenium) four elements constitute the optimal proportion of chalcopyrite crystal thin film Thin film solar cells are the key technology that constitutes the panels. Copper indium gallium selenide thin film material is a direct band gap semiconductor of compound I-III-VI2. The light absorption coefficient reaches around 105. The thickness of the film isabout 1 to 2 μm and can absorb sunlight. The efficiency and production of large-area battery components are based on each company's preparation processes, generally between 10% and 15%.
Zhongyi Xingye copper, indium and gallium thin film solar cells have the characteristics of low production cost, low pollution, non-fading and 'good performance in low light. The photoelectric conversion efficiency ranks first among all types of thin films. solar cells, close to crystalline silicon. The solar cells, whose cost is one-third that of crystalline silicon cells, are known internationally as "a very promising new thin-film solar cell for the next era." Additionally, the battery has a soft, uniform black appearance, making it an ideal choice for locations with demanding requirements.high ences in appearance, such as glass curtain walls in large buildings. It has a large market in modern high-rise buildings and other fields.
Although CIGS cells have the advantages of high efficiency and low material cost, they also face three main problems: (1) complex manufacturing process and low material cost. high investment (2) insufficient supply of key raw materials (3) The CdS buffer layer is potentially toxic.
3. Cadmium Telluride (CdTe) Battery Panel
Cadmium Telluride (CdTe) Thin Film Battery is a photovoltaic device formed by sequentially depositing multiple layers of thin films on a glass or flexible substrate. . Compared with other solar cells, the structure of cadmium telluride thin film solar cells is relatively simple. Generally speaking, thiscell type consists of a five-layer structure on a glass substrate, namely a transparent conductive oxide layer (TCO layer). a window layer, a cadmium tellurium (CdTe) absorption layer, a back contact layer, and a back electrode layer. The conversion efficiency of cadmium telluride thin film batteries is generally 8.5% to 10.5%.
CdTe is a II-VI compound semiconductor with a high absorption rate. It can absorb more than 90% of visible light with just 1 micron (μm) thickness, or 1/100 of monocrystalline silicon. is very suitable for manufacturing the absorbing layer of thin film solar cells is an important prerequisite for achieving low cost and low power consumption. The temperature coefficient of cadmium telluride thin film solar cell modules is about -0.25%/℃, which is about half lowerto that of crystalline silicon solar cells. Therefore, it generates more electricity than crystalline silicon cells with the same power rating and is higher. suitable for high temperature environments. The spectral absorption of cadmium telluride thin-film solar cell modules does not cover the absorption peak of water vapor, so power production does not decrease in humid climates like cadmium telluride thin-film solar cell modules. crystalline silicon.
One of the main disadvantages of cadmium telluride is that it must be made of “extraordinary” materials. Cadmium is a highly toxic substance that can accumulate in the food chain like mercury, which is against green and environmental standards. protection. User-friendly, safe and non-toxic concept.
Thin film batteries consume less materials, have low energy consumption in preparation and production ofcomponents can be produced in a single workshop, with obvious cost advantages. If the efficiency of thin-film solar modules is almost the same as that of crystalline silicon cells, their value for money will be unprecedented. Thin film batteries prepared on flexible substrates have the advantages of being rollable and foldable, low shock prone, lightweight and good performance in low light conditions. This potential, coupled with the application of distributed photovoltaics, such as photovoltaic integration in buildings will have broader application prospects in the future.
The best one at present is gallium arsenide thin film solar cell, with a conversion efficiency of more than 32%, please continue to learn more
L Source Article: Zhongyi Industrial Thin Film Solar Technology Expert