Huasun Energy, a China-based manufacturer of heterojunction solar modules and cells, has reported new tandem efficiency milestones on September 1, 2025. Huasun Energy has achieved 34.02% efficiency on a 1 cm² laboratory device using dual passivation that combines physical field effects and chemical bonding. The laboratory milestone was supported by crystallization additives and high-mobility transport layers that improved grain orientation, energy-level alignment, and interface stability. Huasun Energy has also achieved 29.01% efficiency on a 210 HP production-line cell by applying large-texture thin-film deposition with organic stabilizers. This process has enabled uniform coatings on complex surfaces while strengthening deposition uniformity, environmental stability, and material compatibility. Huasun Energy has further introduced updated interface transport materials to enhance reliability and manufacturing readiness. The 29.01% efficiency was nearly four percentage points higher than single-junction crystalline silicon solar cells, positioning tandem technology closer to commercialization. Earlier this year, Huasun and New Time announced plans for a 1 GW perovskite–HJT plant in Italy.