VIT researchers work on solar cells using MXene-based electrodes, a new 2D material
With the clean energy trend gaining momentum, researchers are in the process of looking at ways to harness solar energy for various commercial applications. In India, the third-generation solar cells are making way for futuristic and cost-effective solar products using nanomaterials.
MXene, a new member of the 2D family, has excellent electrical conductivity, fast diffusion of ions and molecules, good thermal stability.
The energy devices team at the Centre for Nanotechnology Research, Vellore Institute of Technology (VIT), Vellore, led by Dr A Nirmala Grace has undertaken research to improve the performance of Dye Sensitised Solar Cells (DSSCs) by replacing platinum with 2D transition metal nitride (MXenes).
“India is blessed with plenty of sunlight. Solar technology has a huge commercial and industrial potential. Harnessing the sun for energy requirements is the way forward. However, high raw material cost in the making of solar cells makes the end-product expensive. We are working with materials and substrates which can bring the cost down drastically, increase the commercial applications and improve productivity,” said Dr Grace.
She said the most common and highly efficient solar cells are made of crystalline silicon called first-generation solar cells. However, its high manufacturing cost and maintenance have led to development of second and third-generation solar cells. While the second-generation solar cells are thin-film based and costeffective compared to firstgeneration technology, they are comparatively less efficient. The latest technology tries to overcome the drawbacks of the previous two generations of solar cells, she said.
The third-generation dyesensitised solar cells (DSCC), perovskites and organic solar cells find efficient alternate materials to improve performance and productivity.
In the last two decades, dyesensitised solar cells have attracted much attention in the solar energy market for their easy processing and versatility in product integration.
Dye-sensitised solar cell structure and operation exactly mimics nature’s photosynthesis process to harvest energy from the sun, with an efficiency of up to 11- 14%.
“A major drawback in their commercial marketing is the counter electrode platinum, which is expensive, scarce and not stable. Nanotechnology finds a solution to replace the expensive platinum with high surface area 2D nanomaterials that exhibit high electrical conductivity. MXene are a new class of 2D materials which can be used to make solar cells,” she said.
Dr Grace said that initial studies of DSSC using MXene are comparable to those of conventional platinum. The material also poses good stability and corrosion resistance. “Platinum is an expensive metal. MXene can bring down the cost with good efficiency,” she said, adding the preliminary laboratory test on 0.16 cm² area DSSC with transition metal carbide counter electrode showed a remarkable performance close to platinum. This motivated the team to work on large area DSSC solar panel design, with transition metal carbide as the counter electrode, to power portable electronic devices both on rigid and flexible substrates.
She said the researchers are also looking at the possibility of making flexible solar cells to be used in wearable devices, mobiles, calculators and even jackets among others.
Providing clean energy is one of the Sustainable Development Goals according to the United Nations formulation in 2015. This motivates the research and development in harvesting energy from natural resources such as solar, wind and tides.
The centre at VIT Vellore has a focussed research theme on printed and flexible devices for energy, sensors and health care.