Scientists at UNSW Sydney have found a way to make solar panels far more efficient by teaching sunlight to “do twice the work.”
In a new study published in ACS Energy Letters, researchers demonstrated how a thin organic layer can split one particle of sunlight into two, potentially transforming the way solar energy is captured and converted into electricity.
This process, known as singlet fission, could push solar power well beyond its current efficiency limits.
Most solar panels today are made from silicon—a reliable and inexpensive material—but even the best can only convert about 27% of sunlight into electricity, with a hard theoretical limit of around 29.4%.
Much of the remaining solar energy is wasted as heat.
“Essentially, we’re finding ways to take that wasted heat and turn it into extra electricity,” says Dr. Ben Carwithen, a postdoctoral researcher at UNSW’s School of Chemistry.
Singlet fission allows one high-energy photon from sunlight to create two packets of electrical energy, instead of one. That means solar panels could, in theory, generate almost twice the electrical output from the same amount of sunlight.
The idea isn’t entirely new, but making it work in real-world conditions has been a challenge. Earlier experiments used a material called tetracene, which performed well in the lab but quickly broke down in air and moisture.
The UNSW team, nicknamed Omega Silicon, has now shown that a compound called DPND (dipyrrolonaphthyridinedione) can perform singlet fission while remaining stable outdoors.
“We’ve demonstrated that DPND can be layered on top of silicon and inject extra electrical charge into the system,” Dr. Carwithen explains. “It’s the first real proof that this can work in a realistic setup.”
The discovery builds on more than ten years of research led by Professor Tim Schmidt, who first uncovered how magnetic fields influence the singlet fission process.
His work helped scientists understand how light energy can split and transfer between molecules. “Blue light, for example, carries more energy,” Prof. Schmidt says. “Normally, that energy is lost as heat, but singlet fission allows us to capture it instead.”
In practice, the technology would work by adding an ultra-thin organic coating on top of a standard silicon solar cell—“almost like painting an extra layer,” says Dr. Carwithen.
The potential is enormous: while standard silicon panels top out below 30% efficiency, the theoretical maximum for singlet fission-enhanced panels is around 45%.
The research is supported by the Australian Renewable Energy Agency (ARENA) under its Ultra Low Cost Solar program, which aims to create solar panels that exceed 30% efficiency and cost less than 30 cents per watt by 2030.
According to Associate Professor Murad Tayebjee, the project’s supervising author, this marks a “big step forward” in solar technology. And with several major solar companies already watching closely, the UNSW team hopes to deliver a small-scale proof of concept within the next few years.
As Dr. Carwithen puts it, “There could be a big breakthrough tomorrow—or it might take five years. But either way, we’re now on the path to solar panels that could capture nearly half of the sun’s energy.”
Source: University of New South Wales.
