TECH TALK / PEROVSKITE SOLAR CELLS
Researchers at the Indian Institute of Technology (IIT) Delhi, led by Prof Trilok Singh from the Department of Energy Science and Engineering, have made a significant leap forward in solar cell technology. Their groundbreaking development of Perovskite solar cells promises to reduce production costs and streamline manufacturing, paving the way for broader adoption of solar technology worldwide. Published in the journal SMALL, this work presents a transformative approach to fabricating Perovskite cells under standard air conditions, eliminating the need for complex and costly anti-solvent methods traditionally used in production.
The Perovskite solar cells developed by the IIT Delhi team integrate an innovative component: Guanidine sulfate salt, which serves as a stabilising agent. This addition is crucial, as it helps address common issues related to interfacial stresses and defects that typically hinder the cells’ durability and efficiency. By using guanidine sulfate salt, the team has achieved notable advancements in both efficiency and stability of these cells.
A key feature of the IIT Delhi team’s innovation is its durability; these Perovskite cells retained 87% of their initial efficiency after 2,000 hours of continuous operation.
This high level of stability is promising for long-term applications, indicating that Perovskite solar cells may serve as a cost-effective alternative to silicon-based solar cells, which currently dominate the industry.
The thin-film Perovskite solar cells, derived from earth-abundant materials, have a significant advantage over conventional silicon cells. They offer the potential to generate higher energy at a lower cost.
However, scaling up Perovskite technology under ambient conditions has faced challenges, primarily due to the elevated density of defect states generated during production, affecting charge recombination and ion migration.
The IIT Delhi research team tackled these limitations head on. By carefully selecting guanidine sulfate (Gua-S), they proposed an anti-solvent-free fabrication strategy, which not only enhances device reproducibility but also minimises lattice mismatches at the electron transport layer (ETL)/ Perovskite interface. Gua-S contributes to reducing interfacial stresses due to the comparable size of Gu and FA ions, and the amino groups (-NH2) and sulfate anions (SO42−) in the Gua-S salt further address cationic and anionic defects in the cell film.
Highlighting the broader implications of this development, Prof Trilok Singh shared with the PIB: “The device demonstrated exceptional stability, maintaining 87% of its initial PCE after 2000 hours of operation. This highlights the potential of Gua-S as an effective approach for improving both the performance and long-term stability of PSCs. Such innovative solutions, using anti-solvent-free techniques, will promote the upscaling of Perovskite solar cells under ambient conditions.”
This breakthrough in Perovskite solar technology not only reduces production costs but also simplifies manufacturing, making solar energy more accessible and affordable.