What is photovoltaic silver paste?

  The main principle of photovoltaic power generation is the photovoltaic effect of semiconductors, that is, when the silicon wafer is illuminated, the charge distribution state in the body changes to generate electromotive force, converting photons into electrons and light energy into electrical energy. Photovoltaic silver paste is an important electrode material in solar cells, located in the upstream of the industrial chain. Formed by mixing high-purity silver powder, glass oxide/resin and organic support, and stirring and rolling in three rolls, photovoltaic silver paste accounts for about 10% of the cost of photovoltaic cells, second only to silicon wafers.

  Classification of photovoltaic silver paste

  According to the different positions and functions, photovoltaic silver paste can be divided into front silver paste and back silver paste. The front-side silver paste mainly plays the role of collecting and deriving photogenerated carriers, and the front-side silver paste is printed on the light-receiving surface of the P-type solar celland the double-sided of the N-type solar cell in the form of a grid line through screen printing technology to form the front electrode of the solar cell; The silver paste on the back mainly plays an adhesion role, and the requirements for conductivity are relatively low, and are commonly used on the backlit surface of P-type batteries. Compared with the back silver paste, the front silver paste needs to achieve more functions and utility, and the technical requirements of the product are higher. In recent years, due to the new N-type high-efficiency solar cellunit silver paste consumption is higher than the current mainstream P-type solar cell and its market share is expected to gradually increase, coupled with the downstream terminal demand and solar cell production continues to grow, will increase the total market demand for photovoltaic front silver paste.

  According to the classification of technical routes and processes, photovoltaic silver paste can be divided into high-temperature silver paste and low-temperature silver paste. High-temperature silver paste in the environment of 500 °C by sintering process silver powder, glass oxide, other solvents mixed, while low temperature silver paste in a relatively low temperature environment of 200-250 °C silver powder, resin, other solvents and other raw materials mixed, the current P type solar cell and N type TOPCon solar cell is mainly used high temperature silver paste. Due to the unique properties of HJT solar cell amorphous silicon film with high hydrogen content, the temperature of the production process is required not to exceed 250°C, which promotes the research and development of low-temperature silver paste technology and its industrialization.