Solar cell metallization supplier Solamet Materials Science’s Technical Director Zinan Zhang at the TaiyangNews High Efficiency Solar Technologies 2024 conference shared the company’s innovative metallization solutions that improve n-TOPCon efficiency and cost-optimization.
In 2021-2022, manufacturers used a homogenous p+ emitter for TOPCon cells, which led to a manufacturing efficiency of up to 25%. It increased over the years to reach 26% with the transition to LDSE and SE with LECO. Since Q2 2024, the efficiency exceeded 26% with the help of non-SE and LECO.
Zhang stressed that fine-line printing and low solid content rear-side pastes are the 2 mature and effective solutions for TOPCon cost reduction as these approaches reduce silver use. 0BB is also being used to lower silver consumption.
Uniformity in particle size and shape directly impacts paste performance since large particles or irregular shapes can disrupt the paste flow and application uniformity. He gave an example to show how blending silver powders of varying sizes improves flow characteristics.
He explained, “By optimizing the ratio of different silver particle sizes, the solid content, viscosity, and sintering density of the silver paste are balanced, thereby enhancing fine line printability and reducing grid line resistance.”
Solamet’s research also looked into the benefits of structured passivation layers, improving cell performance even in mass production as these reduce recombination and improve carrier lifetimes.
The use of silver nevertheless makes solar production expensive. The industry has been exploring various measures like thinner grid lines and advanced paste formulations to bring down its usage, Zhang added.
For more presentation videos and conference summaries for all 4 days of the TaiyangNews High Efficiency Solar Technologies 2024 Conference, click here for days 1 and 2, and here for days 3 and 4.