QAZAQ GREEN. Researchers from Lehigh University have developed a material with the potential to increase the efficiency of solar panels drastically. But what makes it different?

Constant innovations improving efficiency have become crucial, especially in meeting global energy needs, according to Interesting Engineering.

Quantum material to the rescue

The research team debuted a prototype using a quantum material as the active layer in a solar cell. That material showed a photovoltaic absorption of 80% and external quantum efficiency of up to 190%. This feat is remarkable because it exceeds the theoretical limit set by the Shockley-Queisser efficiency for traditional silicon-based solar cells. In comparison, conventional solar cells have a maximum EQE of 100%.

“This work represents a significant leap forward in our understanding and development of sustainable energy solutions. Highlighting innovative approaches that could redefine solar energy efficiency and accessibility in the near future,” said Chinedu Ekuma, a professor of physics at Lehigh University and author of the research paper, in a statement.

The material’s remarkable efficiency improvement boils down to a unique feature called “intermediate band states.” These intermediate band states refer to specific energy levels within the material’s electronic structure, positioned to be ideal for converting light to energy.

In this new material, the intermediate band states enable the capture of photon energy lost by traditional solar cells. Despite EQE figures of up to 100%, traditional cells lose photon energy through reflection and heat.

The team leveraged “van der Waals gaps,” atomically small gaps between layered two-dimensional materials. They inserted atoms of zerovalent copper between layers of a two-dimensional material made of germanium selenide and tin sulfide.

Consider two thin (two-dimensional) sheets of material with tiny gaps called van der Waals gaps. To make them more efficient, the researchers inserted atoms of a zerovalent copper into these gaps, boosting the cell’s efficiency.

An advanced prototype

After extensive computer modeling of the system, Ekuma developed the prototype.

“Its rapid response and enhanced efficiency strongly indicate the potential of Cu-intercalated GeSe/SnS as a quantum material for use in advanced photovoltaic applications, offering an avenue for efficiency improvements in solar energy conversion,” he said. According to Ekuma, it is a promising candidate to develop next-generation and high-efficiency solar cells.

Incorporating this new material into existing solar energy systems will require additional research and development efforts. However, Ekuma highlighted that the experimental technique used to create these materials is already highly advanced. Over time, scientists have perfected a method that inserts atoms, ions, and molecules into materials with precision.

According to the International Energy Agency, in 2023, solar PV alone accounted for three-quarters of renewable capacity additions worldwide. In 2022, solar PV generation increased by up to 26%, reaching almost 1,300 TWh. That showed the largest absolute generation growth of all renewable technologies in 2022, surpassing wind for the first time in history.

Ekuma’s research was funded in part by a grant from the U.S. Department of Energy.

Details of the research are published in the journal Science Advances.