Two Solar Cell Parameters Introduction

Solar cells are devices that convert solar radiation into electrical energy through the use of photoelectric conversion principles. Solar cells are classified into single crystal cells and polycrystalline cells. The types of solar cells are various. There are mainly 125S crystalline silicon solar cells and SF156M polycrystalline silicon solar cells, but different solar cell parameters are also different. In this article, I will introduce the two solar cell parameters for everyone.

Solar Cell Theory

The principle of solar cells is that the solar energy conversion is based on the photovoltaic effect of the junction. When light strikes the pn junction, an electron-hole pair is generated. Carriers generated in the vicinity of the internal junction of the semiconductor do not recombine to reach the space charge region, but are attracted by the built-in electric field, and electrons flow into the n region, and holes flow into p. As a result, the n region stores excess electrons, and the p region has excess holes. They form a photo-generated electric field opposite to the barrier in the vicinity of the pn junction. In addition to partially canceling out the role of the barrier electric field, the photo-generated electric field also makes the p zone positively charged and the N zone negatively charged. An electromotive force is generated in the thin layer between the N zone and the P zone, which is a photovoltaic effect. At this time, if the external circuit is short-circuited, there will be a photocurrent in the external circuit that is proportional to the incident light energy. This current is called the short-circuit current. On the other hand, if the PN junction is open at both ends, the electron and The holes flow into the N region and the P region, respectively, so that the Fermi level of the N region is higher than the Fermi level of the P region, and a potential difference VOC is generated between the two Fermi levels. This value can be measured and called the open circuit voltage. Since the junction is forward biased at this time, the short-circuit photocurrent and the forward current of the diode are equal, and thus the VOC value can be determined.

Solar Cell Parameters Introduction

1.125S Crystalline Silicon Solar Cell Sheet

125S crystalline silicon solar cells have different grades, and solar cell parameters of different grades are also different. The conversion efficiency of grade A is 18.00%, the maximum power is 2.674-2.696Pm, the maximum power point current is 5.135Im, the minimum power point current is 5.093Im, the maximum power point voltage is 0.525Vm, the short-circuit current is 5.440Isc, and the open circuit voltage is 0.630Voc. The conversion efficiency of grade B is 17.80%, the maximum power is 2.645-2.673Pm, the maximum power point current is 5.111Im, the minimum power point current is 5.057Im, the maximum power point voltage is 0.523Vm, the short-circuit current is 5.410Isc, and the open circuit voltage is 0.628Voc.

The conversion efficiency of grade C is 17.60%, the maximum power is 2.615-2.644Pm, the maximum power point current is 5.075Im, the minimum power point current is 5.019Im, the maximum power point voltage is 0.521Vm, the short-circuit current is 5.380Isc, and the open circuit voltage is 0.627Voc.

2.SF156M Polycrystalline Silicon Solar Cell Sheet

SF156M polycrystalline silicon solar cells have different grades. The conversion efficiency of grade A is 17.50%, the maximum power is 4.258Pm, the maximum power point current is 8.189Im, the minimum power point current is 520Im, the maximum power point voltage is 9.30±5%Vm, the short-circuit current is Isc, and the open circuit voltage is 625 ±5%Voc. The conversion efficiency of grade B is 17.25%, the maximum power is 4.198Pm, the maximum power point current is 8.072Im, the minimum power point current is 520Im, the maximum power point voltage is 9.22±5%Vm, the short-circuit current is 625±5%Isc, The open circuit voltage is 625±5%Voc.

  

Solar Cell Price

Suzhou Shangyunda Electronic Technology Co., Ltd.

1, low-cost supply of solar 125/156 polycrystalline cells - ¥ 2.45

2, low-cost solar photovoltaic battery, 125 battery - ¥ 70.00

3, low-cost sales of solar photovoltaic cells, single crystal cell - ¥ 2.45

4. Sale of Photovoltaic Solar Cells - ¥ 2.45

5, sell low-cost solar single crystal cell 125/156 - ¥ 2.45

6, sell solar cells, 156 single crystal cell, 156 multi crystal cell - ¥ 70.00

Note: This price is for reference only! Due to geographical differences, of course, the price will be different. For more details on the prices, please refer to the local distributors!

Solar cell manufacturers

Wuxi Suntech, Baoding Tianli, Hebei Jingao, Changzhou Tianhe, Suzhou Artes, Nanjing Zhongdian, etc. These are domestic, the price is relatively cheaper.

  

Solar cell production process

Solar cell wafer production process is divided into silicon wafer testing - surface texturing and pickling - diffusion bonding - dephosphorized silicon glass - plasma etching and pickling - antireflection coating - screen printing - Rapid sintering and so on. The details are as follows:

1. Silicon wafer detection The silicon wafer is the carrier of the solar cell. The quality of the wafer directly determines the conversion efficiency of the solar cell. Therefore, the incoming silicon wafer needs to be inspected. Before carrying out the detection of the minority lifetime and resistivity, it is necessary to detect the diagonal and micro-cracks of the silicon wafer and automatically remove the damaged wafer. The wafer inspection equipment can automatically load and unload the wafers, and can place defective products in a fixed position, thereby improving detection accuracy and efficiency.

2. The preparation of surface-texturing single-crystal silicon suede uses the anisotropic etching of silicon to form several million square pyramids, or pyramid structures, on each square centimeter of silicon surface. Before preparation of the fleece, the silicon wafer must first be subjected to a preliminary surface etching, which is then etched to about 20-25 μm with an alkaline or acidic etching solution. After etching the fleece, general chemical cleaning is performed. Silicon wafers that have been surface-prepared should not be stored in water for a long time to prevent contamination and should be formed as soon as possible.

Third, the proliferation of solar cells to form a knot requires a large area of ​​PN junction to achieve the conversion of light energy to electricity, and the diffusion furnace is a special device for the manufacture of solar cells PN junction. The tube-type diffusion furnace is mainly composed of four parts: the upper part of the quartz boat, the exhaust gas chamber, the furnace body part and the gas cabinet part. Diffusion generally uses a phosphorus oxytrichloride liquid source as a diffusion source. Manufacturing PN junctions is the most basic and critical process for solar cell production. Because it is the formation of the PN junction, the electrons and holes are not returned to their original positions after flowing, so that a current is formed and the current is led out by the wire, that is, the direct current.

IV. Phosphorus-Silicate Silicate Glass This process is used in the production of solar cells. Through chemical etching, the silicon wafer is soaked in a hydrofluoric acid solution to produce a chemical reaction to form a soluble complex hexafluorosilicon. Acid, to remove the diffusion after the formation of a layer of phosphosilicate glass on the surface of the silicon wafer. Hydrofluoric acid can dissolve silica because hydrofluoric acid reacts with silica to generate volatile silicon tetrafluoride gas. If the hydrofluoric acid is excessive, the silicon tetrafluoride produced by the reaction will further react with hydrofluoric acid to form the soluble hexafluorosilicic acid.

5. Plasma Etching Because during the diffusion process, even with back-to-back diffusion, all surfaces of the wafer, including the edges, will inevitably diffuse phosphorus. The photogenerated electrons collected on the front side of the PN junction will flow along the edge of the phosphor-diffused region to the back of the PN junction, causing a short circuit. Therefore, the doped silicon around the solar cell must be etched to remove the PN junction at the edge of the cell.

Plasma etching techniques are commonly used to complete this process. The plasma etching is under the condition of low pressure, and the parent molecule of the reaction gas CF4 generates ionization and forms a plasma under the excitation of RF power. The plasma is composed of charged electrons and ions. The gas in the reaction chamber, under the impact of electrons, not only converts into ions, but also absorbs energy and forms a large number of active groups. Active reactive groups reach the surface of SiO2 due to diffusion or under the action of an electric field, where they chemically react with the surface of the material being etched, and form volatile reaction products that separate from the surface of the etched material and are extracted by the vacuum system.

6. The reflectivity of the polished silicon surface of the anti-reflection coating is 35%. In order to reduce the surface reflection and improve the conversion efficiency of the battery, a silicon nitride antireflective film needs to be deposited. PECVD equipment is often used in industrial production to prepare antireflective films. PECVD is plasma enhanced chemical vapor deposition. Its technical principle is to use a low-temperature plasma as an energy source, the sample is placed on the cathode of glow discharge at low pressure, the sample is heated to a predetermined temperature by glow discharge, and then an appropriate amount of reaction gases SiH4 and NH3 are introduced, and the gas After a series of chemical reactions and plasma reactions, a solid film, silicon nitride film, is formed on the surface of the sample.

In general, films deposited using this plasma enhanced chemical vapor deposition method have a thickness of about 70 nm. Films of this thickness have optical functionality. Using the principle of thin film interference, the reflection of light can be greatly reduced, the short-circuit current and output of the battery are greatly increased, and the efficiency is also considerably improved.

Seven, screen printing solar cells after the process of texturing, diffusion and PECVD, has been made into PN junction, can generate current in the light, in order to export the generated current, need to make positive and negative electrodes on the surface of the battery . There are many methods for manufacturing electrodes, and screen printing is currently the most common production process for making solar cell electrodes. Screen printing is the use of imprinting the predetermined graphics printed on the substrate, the device from the back of the battery silver-aluminum paste printing, the back of the battery aluminum paste printing and the front of the battery silver paste printing three parts.

Its working principle is: through the screen mesh part of the mesh through the slurry, with a blade in the screen of the slurry to apply a certain pressure, while moving toward the other end of the screen. In the movement, the ink is pressed by the doctor blade from the mesh portion of the pattern portion onto the substrate. Because the stickiness of the paste makes the imprinting fixed within a certain range, the squeegee in the printing is always in linear contact with the screen plate and the substrate, and the contact line moves with the squeegee to complete the printing stroke.

Eight, rapid sintering through the screen printing of silicon, can not be used directly, need to be sintered by the sintering furnace, the organic resin binder burned away, leaving almost pure, due to vitrification and close contact on the silicon The silver electrode. The sintering furnace is divided into three stages: pre-sintering, sintering and cooling and cooling. The purpose of the pre-sintering stage is to decompose and burn off the polymer binder in the slurry. The temperature gradually rises during this stage; during the sintering stage, various physical and chemical reactions are completed in the sintered body to form a resistive film structure, so as to truly have resistance characteristics. In this stage, the temperature reaches a peak value; in the cooling and cooling stage, the glass is cooled and hardened and solidified, so that the resistance film structure is fixedly adhered to the substrate.

Nine, peripheral equipment in the battery production process, but also need power, power, water supply, drainage, HVAC, vacuum, special steam and other peripheral facilities. Firefighting and environmental protection equipment are also particularly important for ensuring safety and sustainable development. Taking into account the safety factors of special gases such as silanes, it is also necessary to set up a special gas room separately to absolutely guarantee production safety. In addition, silane combustion towers, sewage treatment stations, etc. are also essential facilities for the production of solar cells.

Editor's summary: This article mainly introduces the technical parameters of two different types of solar cells - 125S crystalline silicon solar cells and SF156M polycrystalline silicon solar cells, including their grades, conversion efficiency, and maximum power. Maximum power point current, minimum power point current, maximum power point voltage, short circuit current, and open circuit voltage.

Solar Battery Battery Battery Electric Battery Brand Battery Trang rechargeable battery

IPTV is a system where a digital television service delivered to subscribers using an Internet protocol over a broadband connection.IPTV system including television direct transmission,HD live signal,Program navigation,program trailer,movies on demand,HD movie on demand, local.Network play, does not occupy the hotel broadband resources.And it also has hotel service,detailed description of the hotel to facilitate customers to quickly understand the hotel, including hotel reservations, flowers scheduled.Guests can easily control lighting, air conditioning, television and other controls, including electronic cat's eye, smart door locks.The IPTV System features are simple operation,clear screen.Remote control in the hands, simple to use, old people and young children all can play the interface style of the most in line with the television operation of the Metro minimalist layout, easy to understand, clear font.According to the needs of the hotel to customize the function and service content and can be upgraded in a timely manner, so that the hotel system to stay ahead.Don't affect the decoration of the hotel room walls, no need to replace the TV ,no need to transfor network , the maximum cost savings for the hotel while upgrading the hotel.

The core advantage:

1.Support on demand / Live / spot / strong business, intelligent control based broadcast advertising business, customer value-added services, value-added services, tariff pricing, mall management, monitoring and management, statistical analysis and management etc.

2.Support for multi screen interactive, fast navigation, mobile wizard assistant, intelligent search, interest / hot recommendation and other personalized design custom support user UI and functional requirements of deep customization.

3.LAN transmission and push, fast, high quality, and does not need to occupy the public network bandwidth resources.

4.A cable connect to each room, you can deploy the system, without re wiring.
5.Load balancing supports multiple concurrent processing of user requests, while user request management, service delivery, and business processing are highly efficient in isolation management.

6.Real time synchronization two-shipper hot standby and core data , to ensure that the system has no delay fault downtime, to maintain high availability of services.

7.Support for distributed deployment, according to the capacity of the system program can be seamless expansion of system storage capacity.

8.User request token encryption, core sensitive data and field encryption processing, data transmission encryption, terminal authorization management, to ensure information security.

Smart Hotel IPTV System

Smart Hotel IPTV System,Hotel Internet Protocol Television,Hotel IPTV,Hotel IPTV Solutions

Shenzhen Zhuohao Intelligent Electronic Development Co., Ltd. , https://www.szactop-smart.com