Making solar energy cheaper and more efficient

Harvesting electricity from solar energy is one of the most promising ways to tackle the current energy issues around the globe.

Solar cells made from inorganic semiconductors (IPV) have to date dominated the market, particularly those based on crystalline silicon. Recently, solar cells based on organic materials (OPV) have emerged with the potential for inexpensive manufacture on flexible substrates.

The limitations of IPV are high material and manufacturing costs, while those of OPV are low efficiency and low stability. Researchers, therefore, are paying closer attention to OPVs to increase their power conversion efficiency (PCE).

Schematic representation of Organic solar cell

One such researcher is Naresh Chandrasekaran, who is working at the IITB-Monash Research Academy on a multi-disciplinary project titled, 'Organic Semiconductor-based Photovoltaic Devices'.

The IITB-Monash Research Academy is a collaboration between India and Australia that endeavours to strengthen scientific relationships between the two countries. Graduate research scholars of the Academy study for a dually-badged PhD from both IIT Bombay and Monash University, spending time at both institutions to enrich their research experience. Says Prof Murali Sastry, CEO of the Academy, "As the reputation of the IITB-Monash Research Academy begins to grow and as more organisations start collaborating with us, we anticipate that we will contribute significantly to maintaining India's reputation as a leading-edge global research hub."

Naresh is quick to agree. "My project is designed to develop high performance organic solar cells and understand the device physics involved in it," he says. "I've dreamt for long about working on cutting edge technology that can substantially change the way we live, and I believe organic electronics is capable of doing that. The technology I am working on involves soft materials, i.e. semi-conducting polymers, which are cheap and easily available. However, they are not stable in ambient atmospheric conditions."

The good news is that the power conversion efficiency of tandem organic solar cells has improved significantly. However, understanding the physics involved in these devices is complex, since the phenomenon of charge generation from sunlight in organic semiconductors is different from that of inorganic semiconductors. The challenge is to develop efficient organic solar cells and understand the physics involved inside the device, which is the scope of Naresh's project.

"The most satisfying thing about my research is that organic solar cells are eco-friendly and the outcomes we are working on can have a profound impact on the way we live," says Naresh.

A new generation flexible organic solar in bus stop in Germany (left) and a solar bag (Courtesy:Konarka and Konar Neuber's Solar Bag with Konarka Power Plastic (Photo: Business Wire))

So, the next time you see a bus stop shaded by transparent and flexible organic solar cells, or a solar bag which can generate electricity when you walk on a sunny day, you know whom to thank.

Research scholar: Naresh Chandrasekaran, IITB-Monash Research Academy

Project title: Organic Semiconductor Based Photovoltaic Devices

Supervisors: Dinesh Kabra (IITB) Chris McNeill (Monash)

Contact details: naresh.chandrasekaran@monash.edu

This story was written by Mr Krishna Warrier based on inputs from the research student and IITB-Monash Research Academy. Copyright IITB-Monash Research Academy.