Buried interface regulation with TbCl3 for highly-efficient all-inorganic perovskite/silicon tandem solar cells

In the quest for sustainable and efficient energy solutions, the field of photovoltaics continues to witness remarkable advancements. Among these, all-inorganic perovskite materials have garnered significant attention due to their exceptional thermal stability and tunable optical properties. Recently, under the guidance of Professor Weidong Zhu and Professor Chunfu Zhang from Xidian University, a team of researchers has made a groundbreaking stride by developing highly efficient all-inorganic perovskite/silicon tandem solar cells using a novel TbCl₃ doping strategy. This innovative approach not only enhances the performance of individual perovskite solar cells but also integrates seamlessly with silicon solar cells to achieve remarkable efficiencies.

Why This Research Matters

• High Efficiency: The TbCl₃-doped CsPbI3 perovskite solar cells achieved an efficiency of 18.68%, while the four-terminal (4T) and two-terminal (2T) tandem devices reached efficiencies of 29.40% and 25.44%, respectively.
• Enhanced Stability: The incorporation of TbCl₃ significantly improves the stability of the perovskite films against moisture and oxygen, crucial for practical applications.
• Innovative Doping Strategy: The use of TbCl₃ to modify the interface between the perovskite layer and the hole transport layer (HTL) enhances crystallization and passivates defects, leading to improved optoelectronic properties.

Innovative Design and Mechanisms

• TbCl₃ Doping: The researchers employed TbCl₃ to improve the wettability of the Me-4PACz HTL, facilitating uniform perovskite film coverage and enhancing crystallization. The Tb³⁺ and Cl⁻ ions diffuse into the perovskite lattice, improving stability and passivating defects.
• Interface Engineering: The TbCl₃ doping reduces the work function of Me-4PACz, aligning the energy levels between the perovskite and HTL, which enhances hole extraction and overall device performance.
• Characterization Techniques: Advanced techniques such as X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and time-resolved photoluminescence (TRPL) were used to characterize the improved properties of the perovskite films.

Applications and Future Outlook

• Photovoltaic Applications: The high efficiency and stability of the TbCl₃-doped perovskite solar cells make them ideal for integration into next-generation photovoltaic systems, including building-integrated photovoltaics (BIPV) and large-scale solar farms.
• Tandem Solar Cells: The successful demonstration of 4T and 2T tandem devices highlights the potential for further efficiency improvements by combining perovskite and silicon technologies.
• Future Work: Ongoing research may focus on optimizing the doping concentration, exploring other lanthanide compounds, and developing scalable fabrication processes to bring these high-performance tandem solar cells closer to commercialization.

Stay tuned for more exciting developments from Professor Weidong Zhu and Professor Chunfu Zhang's research team at Xidian University as they continue to push the boundaries of perovskite photovoltaics and contribute to a sustainable energy future.