The new material could significantly increase the efficiency of solar panels

It shows great potential to advance the development of next-generation high-efficiency solar cells that are vital to meeting global energy needs. A team from Lehigh University has created a material that can significantly increase the efficiency of solar panels.

A prototype using this material as an active layer in a solar cell exhibits an average photoelectric absorption of 80%, a high photoexcited carrier generation rate, and an external quantum efficiency (EQE) of up to an unprecedented 190% — a figure that far exceeds the theoretical Shockley-Queisser efficiency limit for silicon-based materials and pushes the field of quantum materials for photovoltaics to new heights.

«This work represents a significant step forward in our understanding and development of solutions of sustainable energy, highlighting innovative approaches that could redefine solar energy efficiency and affordability in the near future», — said Chinedu Ekuma, a physics professor who published a paper on the material's development with Lehigh doctoral student Srihari Kastuar inScience Advances.

Advanced Material Properties

The leap in material efficiency is largely due to its distinct "gap states", specific energy levels that are located in the material's electronic structure in such a way that which makes them ideal for solar energy conversion.

These states have energy levels within optimal subband gaps — energy ranges where the material can efficiently absorb sunlight and produce charge carriers — about 0.78 and 1.26 electron volts. In addition, the material performs particularly well with high levels of absorption in the infrared and visible regions of the electromagnetic spectrum.

In traditional solar cells, the maximum EQE is 100%, which means the generation and collection of one electron for every photon absorbed by sunlight. However, some advanced materials and configurations developed over the past few years have demonstrated the ability to generate and harvest more than one electron from high-energy photons, representing an EQE of over 100%.

Although such multiple exciton generation (MEG) materials have yet to be widely commercialized, they have the potential to significantly improve the efficiency of solar energy systems. In the Lehigh-developed material, the bandgap states allow the capture of photon energy that is lost in traditional solar cells, including through reflection and heat production.

Materials Development and Potential< /h4>

Researchers developed the new material by taking advantage of "van der Waals gaps", the atomically small gaps between layered two-dimensional materials. These gaps can confine molecules or ions, and materials scientists commonly use them to insert or "intercalate" other elements to adjust material properties.

To develop their new material, the Lehigh researchers sandwiched zero-valent copper atoms between layers of a two-dimensional material made of germanium selenide (GeSe) and tin sulfide (SnS).

«Its fast response and increased efficiency strongly indicate on the potential of Cu-intercalated GeSe/SnS as a quantum material for use in advanced photovoltaic applications, offering a path to improve solar energy conversion efficiency», — he said. "It is a promising candidate for the development of next-generation high-efficiency solar cells that will play a critical role in meeting global energy needs.

Although the integration of the newly developed quantum material into current solar energy systems will require further research and development, Ekuma points out to the fact that the experimental technique used to create these materials is already very advanced. Over time, scientists have mastered a method that precisely inserts atoms, ions, and molecules into materials.