Reducing solar energy costs and increasing the efficiency of panels is the path to a sustainable future. And this time, the innovation comes from China. The scientists ofXi’an Northwest Polytechnic Universityin Shaanxi province, have unveiled an advance Perovskite-silicon tandem solar cellpublishing the results in the prestigious journal Journal of Energy Chemistry. Their creation? A four-terminal, semi-transparent cell with an innovative protective layer of indium oxide (In2O3).
What makes this discovery so revolutionary is not only its efficiency, but also the manufacturing process. To create the indium oxide layer, the researchers adopted a low-cost, solvent-free method, which is therefore more sustainable and compatible with large-scale production. This layer serves as protection for the key element of the device: the perovskite absorber and the electron transport layer, which could be damaged during the deposition of the transparent electrodes.
As he explains Li Canlead author of the study:
The optical and electrical properties of In2O3 film strongly depend on the deposition rate. By increasing it too much, you risk obtaining a material rich in indium, with poor transmittance and high absorption loss. By optimizing it, however, we have achieved a perfect balance, with a highly transparent and protective film.
Record performance: efficiency never seen before
The structure of the cell is studied in detail. The upper pérovskite device includes a nickel oxide substrate and a protective cap in bathocuproineelements that improve stability and efficiency. In laboratory tests, this cell achieved a maximum conversion efficiency of 20.20%, already remarkable for an innovative system.
But it was by combining this cell with an inferior silicon cell that the researchers made the leap in quality: the tandem device achieved a record performance of 30.04%ranking among the best technologies ever created in the sector.
In recent years, the photovoltaic sector has seen numerous significant advances, with several efficiency records achieved thanks to technological innovations. For example, the Chinese company LONGi announced that it had achieved 33.9% efficiency with silicon-perovskite tandem solar cells. This result exceeded the theoretical Shockley-Queisser efficiency limit of 33.7% for single junction solar cells for the first time, opening up new perspectives for efficiency and productivity in solar energy.
Also Oxford PVin collaboration with the Fraunhofer Institute, announced that it has achieved a conversion efficiency of 25% for its solar panels. This was achieved through the use of perovskite-on-silicon tandem solar cells, marking a step forward in the solar energy revolution.
Stability and sustainability: the road to commercialization
It’s not just about numbers. Another strong point of this technology is its stability over time. After more than 420 hours of continuous exposure to a light source, the tandem device maintained 80% of its initial performance. A result that opens the doors to a future commercial application.
As Li Can concludes:
This technology represents a fundamental step to accelerate the large-scale diffusion of pérovskite photovoltaic panels. We have shown that it is possible to improve performance without compromising sustainability.
The efficiency of solar panels is a fundamental key to making renewable energy competitive compared to fossil fuels. If pérovskite-silicon tandem cells keep their promises, we could soon see a significant reduction in costs and widespread diffusion of this technology.
