Efficiency record in triple-junction solar cells
Revolution in solar technology with new passivation molecule
1New era in solar energy
Perovskite/perovskite/silicon-based triple-junction solar cells promise to surpass the Shockley-Queisser efficiency limit of single-junction photovoltaics. However, non-radiative losses in wide-bandgap perovskites and light management issues in multilayer structures limit performance. Researchers developed a new passivation molecule called 4F-POEABr, which significantly reduces surface-defect-mediated recombination.
2Chemical and field-effect solution
The 4F-POEABr molecule provides combined chemical and field-effect passivation thanks to its ammonium-attached and electron-deficient structure. This enables a quasi-Fermi-level splitting of 1.53 eV and an open-circuit voltage of 1.413 V in the wide-bandgap sub-cell. The molecule's unique structure effectively passivates defects in perovskite films, boosting efficiency.
3Optimized light management
Researchers used systematic interference management to optimize the current density of the current-limited middle sub-cell. A tailored tin oxide/indium zinc oxide bilayer structure yielded a current gain of 0.5 mA cm⁻². This fine-tuning allows more efficient capture of light at different wavelengths.
4Record efficiency levels
The triple-junction devices achieved certified steady-state power conversion efficiencies of 32.22% for a 1.046 cm² aperture area and 26.97% for a 15.62 cm² aperture area, with negligible hysteresis. Robust interconnection layers and engineered perovskite interfaces enhanced operational stability while reducing device-to-device variation.
5Scalable high performance
The study presents a synergistic strategy to push perovskite/silicon triple-junction solar cells toward their theoretical efficiency limits. The 4F-POEABr molecule and optimized light management pave the way for scalable high-performance photovoltaic technologies. This breakthrough is particularly significant for large-scale solar energy applications.
6Stability and consistency
The developed solar cells demonstrated not only high efficiency but also improved operational stability. Engineered perovskite interfaces and robust interconnection layers significantly reduced performance variation between devices. This is crucial for ensuring consistency in industrial production.
7Global collaboration
The project involved collaboration between Trina Solar and Fudan University in China, along with global research institutions like Imec in Belgium, UNSW in Australia, and the University of Hong Kong. This international cooperation accelerated technological breakthroughs by combining expertise from different disciplines.
8Future of renewable energy
This invention has the potential to revolutionize solar energy technologies. Efficiency levels above 30% could enhance the cost-effectiveness of photovoltaic systems, accelerating the renewable energy transition. It may have transformative effects particularly for energy-intensive industries and large-scale solar farms.
Original article: Nature — Üçlü bağlantılı güneş hücrelerinde verimlilik rekoru