Exploring the Potential and Challenges of Silicon-Based Tandem Solar Cells for a Sustainable Future

Single-junction crystalline silicon solar cells have long been the foundation of the photovoltaic (PV) industry, but they are approaching their theoretical efficiency limit of between 29.4 and 29.5%. With the rapid pace of development, the practical technical limit of around 27.5% in the laboratory and 26% in production could be reached within the next decade. To further boost efficiency, the industry must look to innovative multi-junction cell structures, with silicon-based tandem solar cells offering a promising solution for efficiencies above 28%.

Silicon-based tandem cells combine silicon as the bottom cell with a material like III-V based top cells or perovskites, resulting in laboratory efficiencies well above 30%. This surpasses the theoretical limit of a single-junction silicon cell, demonstrating the potential of tandem cell technology.

However, there are significant challenges to overcome before silicon-based tandem cells can become a mainstream solution:

1. Development of defect-free direct growth: The successful integration of III-V top cells on the unpolished surface of a low-cost silicon cell requires the development of a defect-free direct growth process.
2. Cost reduction in III-V layer fabrication: To make silicon-based tandem cells commercially viable, the fabrication of III-V layers must be made more cost-effective.
3. Stability and low-cost mass production of perovskites: While perovskites hold potential as top cells with record efficiencies above 28%, their long-term stability and cost-effective mass production remain to be proven.

By addressing these challenges, the solar industry can pave the way for silicon-based tandem cells to revolutionize solar cell efficiency. As we strive towards a more sustainable future, these advanced tandem cells hold the potential to make solar energy an even more attractive and competitive option for power generation worldwide.