Nanocrystal Innovation Boosts Efficiency of All-Perovskite Solar Modules

Researchers have achieved a significant breakthrough in solar energy technology by replacing traditional gold-based tunnel recombination junctions (TRJs) in all-perovskite tandem solar modules. Historically, these gold-based layers have limited the performance of tandem cells due to parasitic light absorption and structural instability. By utilizing surface-engineered indium oxide (In2O3) nanocrystals, the team developed a solution-processed interconnecting layer that offers superior optical transparency and improved energy level alignment.

To further optimize the system, the researchers introduced a phosphonic acid additive into the lead-tin perovskite precursor. This additive serves a dual purpose: it enhances the electronic contact between the perovskite and the In2O3 layer to facilitate better hole extraction, and it regulates the crystallization process of the perovskite film. By mitigating residual strain during the manufacturing process, this approach ensures the production of high-quality, uniform films across larger surface areas, which is a critical requirement for commercial viability.

The practical impact of this engineering strategy is substantial. A 65-cm2 all-perovskite tandem module utilizing this new architecture reached a certified power conversion efficiency of 26.2%. Validated by the Japan Electrical Safety and Environment Technology Laboratories (JET), these results demonstrate that the new interconnecting layer effectively balances carrier recombination efficiency with structural durability.

This development represents a major step forward for the scalability of perovskite photovoltaics. By overcoming the limitations of conventional materials, this method provides a robust pathway for manufacturing high-efficiency, large-area solar modules. As the industry seeks more cost-effective and high-performing alternatives to silicon-based cells, this nanocrystal-tailored approach offers a promising solution for the next generation of sustainable energy infrastructure.