Researchers from King Abdullah University of Science and Technology (KAUST), in a significant discovery, have claimed to surpass the efficiency milestone of 30% for tandem silicon-perovskite solar cells.

Tandem solar cells consist of a top cell that absorbs high-energy photons and a bottom cell that captures low-energy photons. These cells are stacked together, with the top and bottom cells interconnected, allowing for efficient energy conversion.

Monolithic integration of perovskite and silicon solar cells into a tandem device holds great promise for high-performance and cost-effective photovoltaics.

Metal halide perovskites have emerged as a promising semiconductor class for solar cells, as their bandgap can be tailored to cover the desirable range for top cells.

Integrating perovskites with silicon into tandems has become a thriving area of research, leading to various deposition techniques involving solution processes, vacuum deposition, or a combination of both.

Initial work focused on developing low-temperature deposition processes for the top cell to ensure compatibility with the highly efficient silicon bottom cell.

One of the main challenges in realizing the potential of perovskite-silicon tandems has been minimizing charge loss due to recombination in the perovskite top cell, particularly at its interface with the electron-collecting contact stack.

Researchers have addressed this issue through innovative molecular approaches. By blending a phosphonic acid-based additive or inserting a chemical component, piperazinium iodide, they achieved certified efficiencies above 30% in different types of perovskite-silicon tandems.

Future Directions and Commercial Viability

Moving forward, efforts are needed to improve further the performance, stability, and scalability of perovskite-silicon tandems.

Assessing the annual degradation rate under real-world conditions and achieving scalability comparable to mainstream silicon manufacturing is crucial for commercial viability.

The researchers said reaching performance, stability, and scaling goals within approximately five years will accelerate the maturation of this renewable energy technology and contribute to meeting the critical target of 75 TW global PV capacity.

Recently, scientists at the National Centre for Photovoltaic Research and Education of the Indian Institute of Technology Bombay achieved a power conversion efficiency of more than 26% for a 4 terminal (4T)-silicon perovskite tandem solar cell.

Last month, Italy-based renewable energy company Enel Green Power, researchers at the National Solar Energy Institute, and the French Alternative Energies and Atomic Energy Commission claimed to have achieved a power conversion efficiency of 26.5% for a 2-terminal tandem perovskite solar cell.