Key takeaways:
HJT remains one of the highest-efficiency mainstream cell technologies, with roadmaps projecting efficiencies approaching 27% by 2035
The technology combines crystalline silicon wafers with thin-film passivation layers to achieve low recombination losses
While manufacturers increasingly focus on module-level metrics, industry roadmaps continue to project a slight efficiency advantage for HJT over TOPCon
Heterojunction (HJT) technology stands out for its hybrid architecture that brings together the best of 2 worlds: the strong light absorption properties of crystalline silicon wafer-based cells and the superior passivation attributes of thin-film technologies. Structure-wise, a crystalline silicon wafer is sandwiched between the stacks of intrinsic amorphous silicon films and oppositely doped microcrystalline silicon thin films. This well-engineered technology has long led the crystalline silicon efficiency charts, including a brief stint in the last 5 years. Most recently, LONGi achieved 26.81% efficiency with an HJT cell at the end of 2022, surpassing Kaneka’s HBC cell. As for mass production, Huasun has been leading the space, reporting 26.5% efficiency at the end of 2024.
Of late, however, companies have stopped emphasizing cell efficiencies, which are now used primarily for internal evaluation; this also applies to HJT. For reference, as in previous editions, we have summarized average efficiency figures published by the CPIA and ITRPV.
According to the former, HJT cell efficiency was at around 25.9% in 2025 and is expected to improve to approximately 26.2% in 2025. The roadmap then indicates a steady increase, reaching about 26.7% by the end of the decade and approaching around 27% by 2035, consistently maintaining a slight efficiency edge over TOPCon. In contrast, ITRPV outlines a more conservative trajectory for the near term. It places HJT efficiency at around 25.7% in 2025, then accelerates to around 26.5% in 2029, and finally to 27% over a 10-year horizon, aligning with CPIA’s estimate.
The text is an edited excerpt from TaiyangNews’ report on Cell & Module Technology Trends 2026, which can be downloaded for free here.