Affordable and Accessible Solar Cell Technology

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.