China Sets New Record: 28.04% Perovskite Tandem Efficiency

• Chinese scientists set a new world record: certified 28.04% steady-state efficiency for perovskite–organic tandem cells, boosted by smarter interfaces that boost transport, cut losses, and support stability.

Chinese researchers report a new world record for perovskite–organic tandem solar cells, achieving a certified steady-state power conversion efficiency of 28.04%. The result sets a higher benchmark for this device class, underscoring fast progress toward next-generation photovoltaics that can outperform conventional single-junction cells.

The team said it boosted performance by optimizing the interface between the perovskite and organic absorber layers to improve charge transport and cut energy losses, while preserving stable operating behavior. Perovskite tandem technology is viewed as a leading route to higher-efficiency, potentially lower-cost solar modules. The advance further highlights China’s growing leadership in solar research.

How did Chinese researchers reach 28.04% efficiency in perovskite–organic tandem cells?

• Designed a perovskite–organic tandem architecture with a bandgap pairing chosen to harvest complementary parts of the solar spectrum, improving overall current matching between the subcells.
  
• Engineered the perovskite top-cell surfaces and interfaces using targeted passivation layers to suppress non-radiative recombination (a key loss mechanism) and to keep charge-carrier lifetimes high.
  
• Optimized the interfacial chemistry and energy-level alignment between the perovskite absorber and the adjacent transport layers to reduce carrier extraction losses and improve both hole/electron selectivity.
  
• Improved charge transport across the tandem stack by using tailored transport-layer compositions and thicknesses so that carriers reach the electrodes quickly rather than recombining within the device.
  
• Tuned the recombination/interconnection region that electrically couples the two subcells to ensure efficient carrier recombination with minimal resistive and optical losses.
  
• Reduced optical parasitic losses with anti-reflection or spectral-management strategies (e.g., managing reflection at layer boundaries and maintaining strong absorption in each subcell).
  
• Minimized electrical resistance across the full device stack (electrode/transport contact optimization), helping the tandem sustain high fill factor under operating conditions.
  
• Controlled morphology and film quality in the perovskite layer(s) to limit defects, enabling more stable carrier generation and extraction during illumination.
  
• Achieved “steady-state” performance by optimizing device operation conditions and measurement protocol (rather than relying only on initial scan maxima), so the certified efficiency reflects stabilized output.
• Used additional stability-oriented measures (encapsulation and/or interfacial robustness strategies) that help maintain the low-loss mechanisms needed to reach high efficiency over time.