Metallization is the key step in the production of crystalline silicon solar cells. The photogenerated carriers are led out of the cell by preparing metalized electrodes on the front and the back of the silicon wafer by screen printing and sintering of conductive paste. Solar cell paste is the key material for metallization, accounting for about 50-60% of the non-silicon cost of cells. The paste is made up of conductive phase, binder and organic carrier, includes front-side silver paste, rear-side silver paste and rear-side aluminum paste, has an important influence on the cell’s photoelectric conversion efficiency and cost.
In 2018, global new PV installed capacity exceeds 100 GW, bringing a huge market of tens of billions to the conductive paste industry. At the same time, crystalline silicon solar cell and module technologies have rapidly been updated due to the continuous demand for efficiency improvement and pressure to reduce costs, which put forward higher requirements for metallization process and paste. The increasing localization rate of front-side silver pastes help cell manufactures to reduce paste cost, and Chinese companies are constantly introducing new conductive pastes for high-efficiency solar cells.
PERC solar cell paste requires a wide sintering process window, and can match the SE process; PERC rear-side silver paste should not fire through the rear passivation layer, has good tension performance and well match PERC aluminum paste. While reducing the consumption of aluminum paste, bifacial PERC requires increasing the aspect ratio of the aluminum grid line and lowering the volume resistivity. The fire-through aluminum paste technology can eliminate the laser opening step of rear passivation layer, and reduce the cell cost.
In 2018, Tongwei, Akcome, Rainbow and other enterprises planned to build new capacity for heterojunction(HJT) solar cell. HJT requires low temperature silver paste, which requires good contact with TCO layer, fast curing to reduce process time, increase tensile force to meet MBB requirements, and stored at room temperature. In addition to the metallization of silver paste, Meyer Burger launches SmartWire connection technology for HJT cells, using copper wire for metallization; Meco launches plating metallization technology to improve cell efficiency.
N-type bifacial cell urgently needs to reduce silver paste consumption to control cost. Passivated contact technology can greatly improve the conversion efficiency of N-type cell, and is an important development direction of N-type cell. The metallization process and conductive paste suitable for N-type passivated contact cell are attracting attention in the industry. Black silicon technology is becoming standard process for multi-Si cell. Black silicon cell surface has special nanostructures, demanding silver paste has high tension and can balance contact resistance and open circuit voltage.
5th Solar Cell Paste and Metallization Forum will be organized by ASIACHEM on 21 March 2019 in Changzhou, Jiangsu, China. The upcoming conference will discuss the global and China’s PV industry outlook and paste market prospect, new high-efficiency solar cell technology and corresponding metallization process and conductive paste, conductive mechanism and contact mechanism of sintered silver paste and low temperature silver paste, front-side silver pastes localization and cost reduction, silver paste and aluminum paste technical progress and investment opportunities, key raw materials production, supply and demand of solar cell pastes, etc.
- Global and China’s PV industry outlook and paste market prospect
- High-efficiency cell metallization process and conductive paste for PERC, HJT and N-type cells
- Conductive and contact mechanism research progress of sintered and low temperature silver paste
- Fire-through aluminum paste and metallization pattern design for PERC
- Screen printing technology improvements and yield enhancement - double printing and dual printing
- MBB cell metallization solutions and ultra-fineline pastes
- Knotless screen technology and supporting pastes
- R&D and application of front-side silver paste for black silicon cell
- Busbarless metallization and plating metallization technologies for HJT cells
- Metallization process and conductive paste for passivated contact cells
- High-efficiency silver paste localization trends and investment opportunities
- Solar cell pastes technology prospect and cost reduction path
- Quality control system for silver paste and aluminum paste mass production
- PV paste key raw materials technologies: silver powder, aluminum powder, glass powder and organic carriers
- Advantages and development prospects of plating metallization technology