Research Projects

Hydrogen is essential for chemical production and clean energy, with a gravimetric energy density far surpassing batteries. While conventional production is carbon-intensive, renewable methods like solar-powered electrolysis offer sustainable solutions, and innovations in solar-integrated systems are key to advancing the green hydrogen economy. Standalone photovoltaic-electrolysis systems are a straightforward method for green hydrogen production; however, the cost is 2–3 times higher than steam-methane reforming (SMR). Water electrolysis requires a minimum thermodynamic voltage of 1.23 V (Gibbs free energy), but overpotentials and resistive losses increase the practical requirement to ~1.5 V. Conventional silicon-based PV, with a VOC of ~0.7 V (Vmpp ~0.6 V), requires at least three cells in series to achieve the necessary photovoltage, limiting the solar-to-hydrogen (STH) efficiency to 10–15% due to the Shockley-Queisser limit. These limitations emphasize the need for cost-effective, efficient, and stable photoelectrochemical systems that can achieve greater than 20% STH efficiency at 1–2 USD/kg to compete with SMR. Proposed Strategies for Addressing Challenges: 1. Hybrid Halide Perovskite Tandem Solar Cells: Perovskite solar cells (PSCs) offer low-cost solution processing with high research-scale PCEs (26.7%) comparable to silicon (27.3%). Their tunable bandgap (1.1–1.8 eV) enables tandem architectures with VOC greater than 2V, efficiently utilizing different regions of the solar spectrum while maintaining cost advantages. 2. Integrated Tandem-PSC Designs: Substrate-configuration tandem-PSCs built on opaque metallic substrates serve dual roles, collecting photogenerated charges for photovoltaic operation and functioning as anodes or cathodes for O₂/H₂ evolution in electrolysis setups. Novelty of the Proposal: This proposal introduces the innovative fabrication of tandem perovskite solar cells (tandem-PSCs) on stainless steel substrates, leveraging the steel's dual role as a substrate for the solar cell and as an oxygen evolution electrode in the electrolysis setup. Unlike traditional PSCs on Glass-ITO, this approach eliminates the need for additional wiring and separate electrodes, reducing costs and resistive losses. Notably, there are no existing reports of tandem-PSC fabrication on stainless steel for water splitting. Dr. Onkar Game’s work on PSCs on opaque substrates (Advanced Materials, IF 27.4) and prior experience in photoelectrochemical water splitting (JMCA, 2012) provide a solid foundation for successfully demonstrating hydrogen generation with this novel design. The successful demonstration of tandem-PSCs on stainless steel enables diverse applications, including Building-Integrated Photovoltaics (BIPV), solar-powered vehicles, UAVs, and integrated energy storage systems. This innovation holds significant potential for renewable energy industries, driving transformative solutions for sustainable development.