TiOx Breakthrough Boosts Tandem Solar Cell Commercialization

• Innovative TiOx interconnect boosts perovskite-silicon solar cell efficiency to 26.5%, paving the way for cost-effective, scalable, and sustainable solar energy solutions.

Researchers at Japan's AIST and the UK's University of Oxford have developed a multifunctional TiOx interconnect to address the complexity of perovskite-on-silicon tandem solar cells, which hinders mass production. The TiOx layer, grown by atomic layer deposition, enables direct series interconnection of a perovskite n-i-p top cell with a silicon wafer, serving multiple functions such as silicon surface passivation and hole extraction.

A proof-of-concept tandem device achieved 22.4% efficiency, with improvements reaching 26.5% by adding a thin ALD-TiNy layer. This innovation matches the performance of reference devices using more complex materials and offers a path to low-cost, scalable, and sustainable solar cell manufacturing by integrating industrial homojunction solar cells into tandem architectures.

How does the TiOx interconnect improve perovskite-on-silicon tandem solar cell efficiency?

• Enhances charge carrier extraction by providing efficient hole extraction from the perovskite layer.
  
• Improves silicon surface passivation, reducing recombination losses at the silicon interface.
  
• Facilitates direct series interconnection between the perovskite top cell and silicon bottom cell, simplifying the tandem structure.
  
• Reduces the complexity and cost of manufacturing by using a multifunctional layer instead of multiple separate layers.
  
• Increases overall device stability and performance by providing a robust interconnect layer.
• Enables scalability and compatibility with existing industrial silicon solar cell technologies.
• Contributes to higher efficiency gains by optimizing the interface between the perovskite and silicon layers.