SAMs Boost Perovskite/TOPCon Solar Efficiency to 31%

• Revolutionary perovskite solar cells achieve 30.9% efficiency with innovative SAMs, paving the way for commercial breakthroughs in sustainable energy.

Researchers from multiple institutions have developed a wide-bandgap perovskite solar device using self-assembled monolayers (SAMs), achieving a power conversion efficiency (PCE) of 22.8%. The SAMs were designed to optimize energy alignment in the perovskite solar cell, maintaining phase stability. The top perovskite cell includes layers such as indium tin oxide, nickel oxide, and a perovskite absorber with a 1.68 eV bandgap, achieving a high fill factor and retaining over 99% efficiency after extensive testing.

The team further integrated this cell with a crystalline silicon TOPCon subcell to create a perovskite/TOPCon tandem device, reaching a certified PCE of 30.9%. The tandem device demonstrated an open-circuit voltage of 1.88 V and a short-circuit current of 20.0 mA cm−2. These advancements suggest that the strategic design of SAMs using the inductive effect can enhance interfacial energetics, potentially aiding the commercialization of perovskite and perovskite/TOPCon tandem solar cells.

How do SAMs enhance efficiency in perovskite/TOPCon tandem solar cells?

• SAMs improve energy level alignment between the perovskite and adjacent layers, reducing energy losses and enhancing charge transfer efficiency.
• They help in passivating surface defects, which minimizes recombination losses and increases the overall efficiency of the solar cell.
  
• SAMs contribute to the stabilization of the perovskite phase, ensuring long-term operational stability and efficiency retention.
  
• By optimizing the interfacial energetics, SAMs facilitate better charge extraction and transport, leading to higher open-circuit voltage and fill factor.
• The use of SAMs can lead to improved light absorption and reduced reflection, further boosting the power conversion efficiency.
  
• SAMs can be tailored to specific chemical and physical properties, allowing for fine-tuning of the device performance and compatibility with different materials.
• They provide a versatile platform for integrating perovskite layers with silicon-based subcells, enhancing the overall performance of tandem solar cells.