Researchers at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, an autonomous institute under the Department of Science and Technology, have developed a next-generation device capable of producing green hydrogen using only solar energy. The device achieves water splitting without the use of fossil fuels or expensive materials, addressing a long-standing barrier to cost-effective, large-scale hydrogen production.
The device is based on a silicon-based photoanode using an n-i-p heterojunction architecture that incorporates n-type titanium dioxide, undoped silicon, and p-type nickel oxide. This structure enhances light absorption, charge separation, and transport efficiency, all of which are crucial for converting solar energy into hydrogen fuel. The materials were deposited using magnetron sputtering, a fabrication method that is scalable and ready for industrial application.
The device demonstrated a surface photovoltage of 600 mV, a low onset potential of approximately 0.11 V, measured against the reversible hydrogen electrode. It can operate continuously for over 10 hours in alkaline conditions with only a 4 per cent drop in efficiency. Furthermore, the research team scaled the device to a 25 square cm photoanode, which maintained consistent performance in solar water splitting. Moreover, with further development and support, this indigenous innovation is expected to contribute to India’s strategy for expanding green hydrogen infrastructure and reducing dependence on fossil energy sources.
