Researchers test solar cell design that reduces energy lost as light
An experimental organic cell gained around 0.85 percent in efficiency, while researchers say the approach could eventually enable efficiencies close to 43 percent.
Researchers at the Institut de Ciències Fotòniques (ICFO) have demonstrated a solar cell design that limits energy escaping as light, improving the experimental cell's efficiency by around 0.85 percent. The team says the approach could, in principle, allow solar cells to approach efficiencies close to 43 percent.
The experiment used an organic solar cell instead of the silicon found in most panels. Researchers swapped its indium tin oxide front electrode for a thin silver electrode and made the cell into an optical cavity. Sunlight could still enter, but less light escaped at wide angles.
The findings, published in Energy & Environmental Science, address Boltzmann loss: energy that solar cells lose through light emission. Other research has focused on limiting energy lost as heat. The team's method targets the difference between the narrow angle at which sunlight enters and the broader angles at which cells emit light.
Dr. Francisco Bernal Texca, the study's first author, said bringing those angles closer together could enable the higher theoretical efficiency. That figure was not achieved in the experiment. The underlying principle should apply to photovoltaic cells beyond the organic type tested, though the research does not mean improved consumer panels are immediately available.
