A handful of resources are needed to sustain life on this planet, such as sunlight. Without it, photosynthesis would not be possible, and human health would decline significantly. It’s also more complex than being a mere ray of light, which can be proven by an invention that could reshape solar panels, among other applications. A specific wavelength of the sun’s versatile spectrum can now be effectively absorbed, opening new doors to sustainable energy solutions and more.
Sunlight: A versatile spectrum of applications
Sunlight brightens the world, not only by providing literal light but also by ensuring that living organisms continue to function effectively and efficiently. However, it also plays a key role in the world of renewable energy solutions, as solar panels would not be able to generate power without solar energy. While the electromagnetic spectrum of sunlight consists of several wavelengths, solar panels usually absorb:
- Visible light (referred to as the seven “rainbow colors”)
- Near-infrared light (usually felt as heat)
In typical silicon-based solar cells, a seemingly “impossible” and unexplored wavelength is not typically utilized to produce solar power. According to a 2025 study about solar photovoltaic output published in Elsevier and available on its platform, ScienceDirect, this wavelength, if absorbed during the day, can overheat the cells of solar panels, causing a drop in efficiency levels.
Fortunately, innovative minds from two independent studies have been researching approaches in which this wavelength can be absorbed efficiently instead of being lost as heat. These approaches play a key role in next-generation solar technologies, as well as a variety of other applications.
Absorbing an impossible wavelength: The forgotten invention
In a study published September 2024 in the scientific journal, Elsevier, a team of researchers from Shenzen University, led by Muhammad Asif, focused on engineering a new solar absorber to absorb a range of wavelengths (broadband absorption) to boost efficiency. The pioneering metamaterial, referred to as GDPT, consisted of:
- Graphene (2D)
- Dielectric silica layers
- Aluminum oxide
- Vanadium dioxide for phase transition
The results were promising, as broadband absorption surpassed 90% across a variety of wavelengths, including the near-infrared. Absorption efficiency was more than 95.9%. However, the previously unexplored mid-infrared wavelength can now also open doors to more efficient solar output thanks to another groundbreaking metamaterial.
The main challenge of using mid-infrared (mid-IR) for solar power production is that most of the energy is lost as heat, which negatively impacts solar cells’ efficiency. Some researchers, on the other hand, have been exploring on using lost solar heat to generate power at night, showing the potential mid-infrared. Now, another new metamaterial can exploit this wavelength in various new ways.
Improving solar panels and so much more
In another study led by led by Asif, published on December 2025 and available on the scientific journal Elsevier’s platform Science Direct, an “ultra-broadband mid-IR absorber” was created using a high-tech insulator-graphene-insulator-metal metamaterial consisting of layers of:
- Alumina
- Graphene
- Silica
- Iron
The absorption efficiency results were impressive. The metamaterial enabled 95.7% ultra-broadband absorption, and also achieved two 99.9% absorption peaks. While this may generally seem like a negative aspect in traditional solar cells, the study adds that this quality holds tremendous potential in the following applications:
- Next-generation solar cells
- Thermophotovoltaics
- Infrared photodetectors
- Stealth technology
This research and results prove that we are nearing a period of transition to the next-generation of solar energy harvesting, with specialized focus on a wavelength once though to be impossible to exploit. The breakthrough with this ultra-broadband mid-R absorber’s absorption efficiency opens new doors to producing clean, sustainable and efficient power, possibly day and night. Another unique design focused on exploiting infrared light by drawing inspiration from nightvision goggles. We are truly living in the future!
