Monocrystalline silicon refers to the overall crystallization of silicon material into a single crystal form, which is currently commonly used photovoltaic power generation material. Monocrystalline silicon solar cells are the most technologically mature among silicon-based solar cells. Compared with polycrystalline silicon and amorphous silicon solar cells, its photovoltaic The conversion efficiency is the highest. The production of high-efficiency monocrystalline silicon cells is based on high-quality monocrystalline silicon materials and mature processing techniques.(ITEHIL foldable solar panel are one of the first stores to use monocrystalline silicon technology)
Monocrystalline silicon solar cells use monocrystalline silicon rods with a purity of up to 99.999% as raw materials, which also increases the cost and is difficult to use on a large scale. In order to save costs, the current application of monocrystalline silicon solar cells has relaxed material requirements, and some of them use the head and tail materials of semiconductor device processing and waste monocrystalline silicon materials, or they are made into monocrystalline silicon for solar cells after compound drawing. Great. Monocrystalline silicon wafer texturing technology is an effective means to reduce light loss and improve cell efficiency.(ITEHIL foldable solar panel use monocrystalline silicon, which has a conversion rate of up to 23%).
To process solar cells, first doping and diffusing on silicon wafers. Generally, trace amounts of boron, phosphorus, and antimony are the dopants. Diffusion is carried out in a high-temperature diffusion furnace made of quartz tubes. In this way, a P>N junction is formed on the silicon wafer. Then use the screen printing method, the finely prepared silver paste is printed on the silicon wafer to make grid lines. After sintering, the back electrode is made at the same time, and the surface with the grid lines is coated with an anti-reflection source to prevent a large number of photons. Reflected off by the smooth surface of the silicon wafer.
Constitutive effect
- Tempered glass Itsfunction is to protect the main body of power generation (such as cells), and the selection of light transmission is required. First, the light transmittance must be high (generally 91% is used on monocrystalline silicon solar cells); second, ultra-white tempered treatment.
- EVA It is used to bond and fix the tempered glass and the main body of power generation (such as cell). The quality of transparent EVA material directly affects the life of the module. The EVA exposed to the air is easy to age and yellow, which affects the light transmittance of the module. In addition to the quality of EVA itself, the power generation quality of the module is also very affected by the lamination process of the module manufacturer. Module life (ITEHIL foldable solar panel use ETFE film imported from Japan to make solar panels more durable and have a longer service life).
- Battery slice The main function is to generate electricity. The mainstream in the main power generation market is crystalline silicon solar cells and thin-film solar cells, both of which have their own advantages and disadvantages. Crystal silicon solar cells have relatively low equipment costs, high consumption and cell costs, and high photoelectric conversion efficiency; thin-film solar cells are more suitable for power generation under outdoor sunlight, and the equipment costs are relatively high, and the consumption and battery costs are very low. The photoelectric conversion efficiency is more than half that of a crystalline silicon cell, but the low-light effect is very good, and it can generate electricity under ordinary light, such as the solar cell on the calculator.
- Backplane The function is that sealing, insulation, and waterproofing are generally made of TPT, TPE and other materials that must be resistant to aging. At present, component manufacturers have a 25-year warranty. Tempered glass and aluminum alloy are generally okay. The key is whether the backplane and silica gel can meet the requirements. We know that the power generation efficiency of a single cell is very low. For example, the power of a 156 cell is only more than 3W, which is far from meeting our needs. Therefore, we have connected more cells in series to meet our requirements. Power, current, voltage, and the cells connected in series are called battery strings.
- Aluminum alloy Protect the laminate, play a certain role in sealing and supporting.
- Junction box Protect the entire power generation system and play the role of a current transfer station. If the component short-circuit junction box automatically disconnects the short-circuit battery string to prevent burn-out of the entire system junction box, the most important thing is the selection of diodes. Depending on the type of cell in the component, The corresponding diodes are also different.
- Silica gel Sealing function, used to seal the component and aluminum alloy frame, component and junction box (the junction box of ITEHIL foldable solar panel adopts waterproof zipper, IPX4 waterproof, which effectively extends the service life). Some companies use double-sided tape and foam To replace silica gel, silica gel is widely used, which is simple, convenient, easy to operate, and low cost.
