New solar cell model challenges 80-year-old equation

TBS Report

August 10, 2024, 10:10 AM

Last Modified: August 10, 2024, 10:14 AM

The new model helps to improve electrical energy collection and reduces recombination losses in diodes. Photo: Collected

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The new model helps to improve electrical energy collection and reduces recombination losses in diodes. Photo: Collected

Physicists from Swansea University and the University of Åbo Academy have developed an analytical model that helps better understand and improve the performance of thin-film photovoltaic (PV) devices, and how flexible and inexpensive solar cells can achieve greater efficiency. The model challenges 80 years of knowledge about how solar cells work.

As SciTechDaily reports, the new model challenges the Shockley diode equation that has long explained the flow of electric current through solar cells.

Thin-film solar cells, made of flexible and inexpensive materials, have often struggled with efficiency. Existing analytical models could not fully explain why these cells did not perform as well as traditional silicon-based cells.

New research sheds light on this mystery, showing that achieving higher efficiency in these cells requires a careful balance between storing electrical energy and minimizing a process called recombination.

What is recombination?

Recombination occurs when electrical charges cancel each other, reducing the amount of electrical energy that can be harvested.

Put simply, it’s like a water leak from a pipe—we lose some of what we’re trying to save. The new model helps scientists understand how to minimize that loss, especially in next-generation thin-film solar cells, which are more likely to recombine because of their structure.

Catching the missing piece

The key to the success of the new model is solving the problem of “injected carriers”, i.e. charges that enter the solar cell from the electrical contacts.

Dr Oskar Sandberg, lead researcher at Åbo Akademi University, explained that their findings shed new light on what drives or limits the performance of cheap and flexible solar cells.

Associate Professor Ardalan Armin from the University of Swansea added that by introducing a new version of the diode equation, the team had a more complete picture of how solar cells work.

Impact on the future development of solar cells

This new knowledge is expected to have a significant impact on the development of next-generation solar cells. The model offers a new way to design more efficient thin-film solar cells and improve existing ones.

It also helps train the machines used to optimize these devices, a major step forward in solar energy technology.

This advancement could lead to cheaper and more efficient solar panels, making solar energy a more viable option for widespread use in the future.