THIRUVANANTHAPURAM: Has your mobile phone run out of battery while on the move? Forgot to carry an adapter or power bank? No need to worry. In near future, the dress that you wear may be able to harvest solar power which can charge mobile phones and other electronic devices. Designing a plastic or flexible solar cell, that can be incorporated into textile, may not be an entirely new concept. But, harvesting solar energy efficiently from these cells has always been a big challenge. Now, a team of researchers from Indian Institute of Science Education and Research (IISER) here, have designed plastic solar cells, the efficiency of which matches international standards.
A ‘first-of-its-kind’ cell
The flexible solar cell, developed by a team led by Manoj A G Nampoothiri, Assistant Professor, IISER, and researcher Minu Mohan, has a power conversion efficiency of 9.1 per cent. According to the researchers, it is the highest efficiency achieved from a plastic solar cell in India, raising hopes of its use in daily life.
A few European countries and the US had recently designed plastic solar cells which have a power conversion efficiency of over 10 per cent. An attempt by Indian researchers to come close to that level has paved way for its application in various fields, including textile electronics. The research was carried out on the Vithura campus of IISER using a Rs 2 crore fund provided by the Department of Science and Technology, Government of India.
The advantage
Currently silicon panels are used in rooftops for harvesting solar energy. Once the panel consisting of photovoltaic cells are fixed, it cannot be easily moved around or re-installed. On the other hand, plastic solar cells, which are like tarpaulin, can be quickly installed and moved around in any sun-lit area.
“One of the drawbacks of a photovoltaic device is the lack of efficiency in extraction of free carriers to the external circuit. But our research has improved the free carrier extraction, thereby improving the power conversion efficiency of the solar cell,” Manoj said.
According to him, unlike silicon, the making of plastic solar cells do not need a clean room or costly equipment. “Plastic solar cells can be made at a lower cost and can be deployed in villages. What’s more, such cells can be manufactured over a large area using screen printing or even roll to roll printing,” he added.
The future
The research team is currently engaged in work to increase the area of the solar cell from the present 3 mm x 3 mm to 1 cm x 1 cm. This would mean that the cell would cover a larger area for better energy harvesting. Efforts are also on to mount the cells onto more flexible materials that are in use in daily life.