Bifacial solar cells top 32% efficiency with new design breakthrough

Researchers from Soochow University, Zhejiang Jinko Solar, and collaborators have developed a novel bifacial solar cell architecture that overcomes efficiency limitations in traditional TOPCon (tunnel oxide passivating contact) solar cells. Conventional TOPCon designs rely on a boron-diffused p+ emitter on the front side, which causes significant recombination losses, and require thick polysilicon layers that increase optical absorption and reduce performance. The new design replaces the full-area front emitter with a patterned n-type TOPCon contact beneath metal fingers, reducing optical losses while maintaining strong electrical contact. Additionally, improvements in silicon surface smoothing and a gradient thermal field deposition process enhanced crystal growth and doping efficiency. This breakthrough architecture demonstrated a certified efficiency of 26.34% in industrial-size TOPCon prototypes and showed strong compatibility with perovskite tandem solar cells, achieving a certified tandem efficiency of 32.73%. Tandem cells stack layers with different bandgaps to capture more sunlight, and the new TOPCon