Indian Institute of Technology, Guwahati researchers have developed hybrid perovskite-based solar or photovoltaic devices, which are highly efficient, cost-effective, easy to manufacture, and easily recyclable when it comes to producing electricity from the sunlight.

The emerging perovskite-based semiconducting devices are considered the most promising due to their low-cost, ease of manufacturing as roll-to-roll devices, high material availability, and easy recyclability.

These devices were developed to achieve power conversion efficiencies beyond 21 per cent by utilizing economical solution-based photovoltaic device processing techniques at mild room temperature and realizing high ambient, thermal and optical stability.

Among all the renewable energy sources, the energy from the sun (solar energy) is considered to be the most sustainable due to its ample availability on the surface of the earth. Currently, inorganic solar cell (Silicon-based) is a major player in the market. However, this technology requires high-temperature processing, which results in the high price of solar panels. Further, the recycling of solar panels is hazardous and complicated.

“The perovskite solar cells (PSCs) research has experienced tremendous attention due to their exponential growth in terms of efficiencies achieved within a decade. However, the perovskite materials are extremely unstable towards ambient (humidity and oxygen) conditions that restrict their commercialization,” said a release from IIT-Guwahati.

The research team at IIT-Guwahati comprising research scholars Rabindranath Garai (Department of Chemistry), Ritesh Kant Gupta (Centre for Nanotechnology), Arvin Sain Tanwar (Department of Chemistry), and Maimur Hossain (Department of Chemistry), all working under the supervision of Professor Parameswar K. Iyer, Department of Chemistry and Centre for Nanotechnology and School for Health Science and Technology, IIT Guwahati, have achieved the results in terms of efficiency and stability of the PSCs.

This recent study of IIT-Guwahati, published in the American Chemical Society journal ‘Chemistry of Materials’ mentioned how charged conjugated polymers have been incorporated in photovoltaic devices as a passivation molecule to achieve defect-free high-quality perovskite solar cell devices.

The passivated defect-free device reveals a high efficiency of 20.17 per cent with excellent reproducibility. Such polymer-based passivation method effectively improved the long-term device stability by improving the hydrophobicity of the perovskite layer.

In another recent investigation by the team, published in The Royal Society of Chemistry journal ‘Journal of Materials Chemistry A’, the researchers demonstrated the development of solution-processed multi-dimensional (2D-3D) graded perovskites and the precise role of surface re-crystallization to achieve very high efficiencies, stability, economical device scalability by mitigating the perovskite defects.

Speaking about this research output, Prof Iyer mentioned that organic-inorganic hybrid PSCs have experienced rapid growth in terms of efficiency and stability due to the development of highly efficient functional materials combined with careful device engineering. The materials design can be tailored at the molecular level whereas the fabrication process is printable and solution-based, making the overall solar cell development process economical and scalable.

These results obtained from perovskite solar cells have performed well beyond the commercial inorganic solar cells panels which are available in the market presently. Also, these small and large area devices performances are among the best results achieved using these classes of perovskite materials. “Therefore, the strategies being developed have the potential to address the renewable energy challenges regarding the large-scale commercial fabrication of efficient and stable solar panels,” the release added.