Increasing the efficiency of solar cells

Solar energy and devices that generate or run on have been researched for increasing cleaner energy’s application as well as the efficiency of the cells that store the energy. Voltage loss has remained a matter of concern for the scientists since solar cells are used to power up our satellites distant from us but serving as our spy in the depth-less universe. Recently a team of about twenty-five researchers from seven different institutes came up with a modification in the design of solar cell which is supposed to increase its efficiency and reduce the loss of voltage. Mr. Feng Gao, Associate Professor at Linkoping University, Sweden led this team.

The carbon-based material was used to develop these organic solar cells. Unique advantages like lower manufacturing cost, higher flexibility, and lower weight make these cells a feasible solution to some of the significant issues faced in harnessing solar energy. Energy loss and high cost have limited the use of the solar power on our planet. If these two problems are looked after, a newer and greener source of energy will power up the majority of our appliances. This can be done using a rational design of the cell as per Associate Professor Feng Gao, who is addressing the division of biomolecular and organic electronics.

His design rules can save a significant amount of the energy that is lost due to inappropriate storage or improper energy conversion practices.  It was believed that solar cells had an efficiency of only 25%. The theoretical limit for the same is 33%. Though we have managed to make this theoretical limit practical, still we did not make the most of it. Olle Inganas, Professor of Biomolecular and organic electronics, Linkoping University, has stated that there is no difference in the theoretical limit and practically feasible vale if the cells are designed manufactured appropriately. 

Two fundamental rules can be used to solve the problem of energy loss in a solar cell:

1.    Minimizing the energy offset period

When the cell absorbs photons from the sun, electrons move to an excited state. Since holes are formed in the ground state, the particles remain attracted to them.  To separate these electrons from holes an medium is required. For the flow of energy, a donor and receiver of electrons are essential, the loss of power during this transfer is high. Minimizing the time of transmission of particles between donor and acceptor components can help solve the problem. 

2.    Increasing the efficiency of the low-gap element.

To remove electrons from their position and allow the flow of energy, a medium is added. This medium should have high photoluminescence.

Several materials have been used to achieve these targets; some proved to be incompatible while some are still under research to offer the best out of solar cells.