Engineers from the Russian company "Hevel", specializing in the production of solar panels in Novocheboksarsk (Chuvash Republic), together with scientists from their own Scientific and Technical Center, have introduced a new conductive paste into the production cycle for forming a current-collecting grid of silicon photovoltaic converters. The key difference of the development was the partial replacement of expensive silver with copper, which significantly reduced the cost of production without compromising electrical characteristics.
Previously, the paste consisted of 100% silver, but now its content has been reduced to 60%. The new formula contains microscopic balls up to 4 μm in diameter, inside of which there is a copper core covered with a layer of silver. This innovation prevents copper oxidation, while the main characteristics of the product remain unchanged.
According to Igor Shakhrai, Chairman of the Board of Directors of Hevel Group, in the near future the company intends to reduce the proportion of silver in the paste to 10%, continuing to optimize materials to improve the economic efficiency of solar modules.
According to industry experts, reducing the silver content in photovoltaic elements is a global trend driven by the increasing specific consumption of this precious metal as technological generations of solar cells change. According to the Chinese manufacturer Changzhou Fusion New Material, the use of composite copper-silver pastes in the production of heterojunction elements reduces silver consumption by 2.5–3 times.
