A German institute just broke the solar cell efficiency record with 32.5 percent
A tandem solar cell developed by researchers at the Helmholtz Zentrum Berlin (HZB) has converted 32.5 percent of incident solar radiation into electrical energy, a world record. The achievement was certified by the European Solar Test Installation (ESTI) in Italy, a university press release said.
As the demand for renewable energy grows, researchers are looking at ways of increasing the efficiency of solar cells. This enables more energy to be harvested from the same area of land deployed to generate power. There has been significant success when halide perovskites have been used to make solar cells.
However, perovskites are prone to rapid degeneration. Therefore, researchers are now working on alternating them with other materials inside a solar cell to increase their life span. These are known as tandem solar cells and hold the promise of being commercially viable.
According to the Office of Energy Efficiency and Renewable Energy in the U.S., perovskites have increased the energy conversion efficiency of solar cells from a meager three percent in 2009 to over 25 percent today.
The new world record
The researchers of the PV Competence Center (PVComB) and the HySPRINT Innovation lab at the HZB worked together to develop a tandem solar cell to break the world record.
The researchers put to work an advanced perovskite composition and combined it with an interface modification that helped reduce the charge carrier recombination losses. The effects of this modification were studied in-depth and then used to design tandem solar cells which also had optical improvements on them.

Put together, the improvements made to the design of the solar cell helped it achieve a 32.5 percent energy conversion efficiency, a world record.
Major strides in solar energy research
While the record is a feat in itself, a greater feat is the rate of progress that solar cell research has been achieving recently. The perovskite solar cells have enabled solar efficiencies to climb significantly, but research institutes across the world have been pushing the limits on what can be achieved.
It was only in late 2021 that HZB broke the previous world record for energy conversion efficiency of the solar cell when it achieved a 29.8 percent conversion. Come summer 2022, Ecole Polytechnique Fédérale de Lausanne in Switzerland broke the 30 percent barrier for energy conversion when it recorded a 31.3 efficiency.
In September, the researchers at the Eindhoven University of Technology also published their innovation about a four-terminal perovskite-silicon solar cell design that also broke the 30 percent barrier.
With the recent achievement, the record may be back to the HZB, but researchers at other institutes are also pushing the limits of what is possible with solar cells and promising a brighter, greener future for the planet.