China Sets 24% Record for Large-Area Perovskite Modules

• Certified by TÜV SÜD, Chinese-made large-area perovskite modules hit 24.0% (810 cm²) and 22.0% (meter-scale), boosted by SVP processing and Pb(OA)₂ passivation—95%+ stability.

Chinese researchers led by Nanjing University and Renshine Solar have set a certified efficiency record for large-area perovskite solar modules, reaching 24.0% on an 810 cm² aperture module and 22.0% on a 0.72 m² (meter-scale) module. The teams report the result was confirmed by TÜV SÜD in China.

They attribute the performance and durability to high-saturated-vapor-pressure (SVP) processing plus chemically stable lead carboxylate passivation using lead dioleate (Pb(OA)₂) on an FAI-enriched surface. XPS indicates chemical bonding, while photoluminescence lifetimes rose from 264 ns to 706 ns. Modules retained 96% efficiency after 2,200 hours of MPPT and met IEC 61215 reliability requirements, with strong damp-heat, thermal-cycling, and ultraviolet stability.

How did SVP processing and Pb(OA)₂ passivation enable 24% certified perovskite module efficiency?

How SVP (high-saturated-vapor-pressure) processing helped:
- Promoted more uniform, dense perovskite crystallization across large areas, reducing the formation of non-uniform phases and composition gradients that typically cap module performance.
- Improved perovskite film morphology (fewer pinholes/voids and reduced surface roughness), which lowers leakage pathways and strengthens contact with adjacent charge-transport layers.
- Enhanced surface and grain-boundary “healing” during growth, which reduces trap density and enables higher open-circuit voltage and fill factor on module scale.

How Pb(OA)₂ passivation enabled better charge extraction and recombination control:
- Used lead dioleate [Pb(OA)₂] as a chemically stable lead carboxylate passivant to neutralize defect sites associated with lead- or halide-related under-coordination common in perovskites.
- Created chemical bonding between the passivant and perovskite surface/defect chemistry, suppressing non-radiative recombination at interfaces and grain boundaries.
- Helped preserve interfacial energetics critical for device operation by making the perovskite surface more chemically compatible with surrounding layers, improving carrier extraction rather than trapping carriers.

Why the combination translated into 24% certified module efficiency:
- SVP processing reduced the bulk and grain-boundary defect landscape during film formation; Pb(OA)₂ then capped remaining surface/interface defects that survive growth.
- Lower trap-assisted recombination increased carrier lifetimes and quality of photogenerated carriers throughout the perovskite layer and at critical interfaces.
- Better film uniformity across the full aperture area increased the likelihood that current collection is consistent across the module, improving current–voltage characteristics at scale.
- The passivation strategy stabilized the perovskite’s optoelectronic properties under operational stress (not just initial performance), supporting high fill factors and sustained efficiency—key for certified module metrics.

Experimental indicators linking the mechanisms to performance:
- XPS results consistent with Pb(OA)₂ chemical bonding support that passivation is not merely physical coverage but defect/chemical-state modification.
- Photoluminescence lifetime increase from 264 ns to 706 ns indicates reduced non-radiative recombination, aligning with the expected defect passivation from Pb(OA)₂.
- Retention of high efficiency after long-term maximum power point tracking demonstrates that the combined SVP growth + Pb(OA)₂ passivation mitigated degradation pathways that would otherwise lower module efficiency over time.