There are three kinds of conductive paste used in solar applications, namely front silver paste, rear silver paste and aluminum paste. The front conductive paste collects the electricity generated by the solar cell while rear paste transmits the collected energy to the system. The paste has a crucial impact on cell’s conversion efficiency and thus plays an important role in the crystalline silicon solar cell’s performance-to-cost ratio. Some manufacturers replace rear silver paste with alumium paste to save production cost.
Notably, as solar cells are progressively made thinner as a result of technology advancement, deformation becomes an issue. To effectively reduce the cell’s warp without affecting the conversion efficiency, the conductive paste is the key factor.
The technology threshold of this particular sector of the solar industry, solar conductive paste, has raised the entry barrier to other market entrants. Unless one’s product quality is proven to be sufficiently better than other’s, cell manufacturers usually are unwilling to switch suppliers.
According to EnergyTrend, the conductive paste accounts for 30~40% of the manufacturing cost of a single solar cell, any slight change to the paste will have an effect on the conversion efficiency. Typically, the conductive paste industry’s success is not built on price competition but quality (reliability and durability) of products.
Dupont and Ferro are the two largest global suppliers of front silver, rear silver and aluminum solar paste. Other major suppliers include Heraeus focusing on front and rear silver paste, Analog focusing on rear silver paste and aluminum paste, Toyo focusing on aluminum paste and China-based Rutech focusing on aluminum paste. Although cell manufacturers’ wide capacity expansion has caused much price pressure of oversupply, the solar paste industry can still embraces promising return due to high profit margin as well as demand from capacity expansion of the solar industry.