IIT Delhi researchers find way to develop perovskite solar cells without using anti-solvents

The thin films solar cells, created from an earth abundant emerging solar material “Perovskite” have the potential to generate higher solar energy at a lower cost than today’s matured industry-standard silicon solar cells. However, scaling the Perovskite technology at ambient conditions without using antisolvent process has hampered its development.

The elevated density of defect states generated during device preparation significantly influences the processes of charge recombination and ion migration.

A team of IIT Delhi researchers led by Prof Trilok Singh at the Department of Energy Science and Engineering (DESE) has been extensively working on to find a potential solution to overcome these defects, stresses, and lower reproducibility issues of devices.

In their recent publication in SMALL Journal (Wiley), the team managed to fabricate Perovskite solar cells under ambient conditions with higher efficiency and stability. Further, by carefully selecting the molecule they have proposed an anti-solvent-free device fabrication strategy to manage the reproducibility of devices.

To prevent the lattice mismatch at the electron transport layer (ETL)/Perovskite interface, the team employed Guanidine sulfate salt (Gua-S). Gua-S potentially reduces interfacial stresses due to the comparable size of Gu and FA ions. Moreover, these salts can tackle cationic and anionic defects in the film. This is because of the presence of amino anchoring groups (-NH 2 ) and sulfate anion (SO 4 2− ) in the Gua-S salt.

“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 solution of using anti-solvent-free techniques will promote the upscaling of perovskite solar cells under ambient conditions,” said Prof. Trilok Singh, DESE.