An international team of researchers developed one innovative technique to control the orientation of crystals In the films in large bankite perovskite (Wide Bandgap), keeping an effective transmission of the offices. This method has been successfully applied in one Solar cell tandem entirely in perovskitereaching a certified efficiency of 29.1% and an open circuit voltage of 2.21 V.
Advanced techniques to improve the efficiency of solar cells in Perovskite
The team, led byUniversity of Nanchino in Chinahas created a 0.049 cm² solar cell that reduces open circuit voltage losses in the large banned band subcell and improves overall performance.
The key to this success lies in the use of perovskiti two -dimensional (2D) As an intermediate phase on the surface of the film, which allowed to reduce non -radiative recombination. “In our laboratory tests, we have reached a record efficiency of 29.7%, with an open circuit voltage of 2.175 V, a current density of 16.4 but/cm² and a filling factor of 83.3 %, “Said Renxing Lin, co-author of the study. The results were certified by the Japanese Japan laboratory (Japan Electrical Safety and Environment Technology Laboratory).
Improve the crystalline orientation of the Perovskiti
The researchers have shown that, through a compositional engineering of the surface, it is possible to increase the amount of two -dimensional phases without having to resort to an excessive amount of 2D binders, which otherwise would limit the transport of the offices. In particular, during the manufacture process, they were added Phoeniletilammonio iodiro (Peai) And Metilammonio iodiro (never) AntiSolvento, forming a thin layer of 2D perovskite on the surface of the broadband subcell wide.
This layer has favored the vertical growth of three -dimensional crystals (3D) oriented along the axis (100), thanks to the reduction of interface energy in 2D/3D heterostrati. “The treatment with an anti -solventing has improved not only the surface of the perovskite, but also significantly influenced the crystallographic orientation, promoting a more favorable alignment,” explained Lin.
The result was a high quality perovskite film with orientation (100), which made it possible to suppress non -radiative recombination and to obtain an open circuit voltage of 1.373 V for a bandgap of 1.78 EV and an efficiency of the 21.1%.
Tandem configuration and long -term stability
To obtain such high performances, the tandem cell was built by combining the broadband subcell wide with a prohibited band -prohibited band subcell. The latter was optimized through a well-calibrated optical-electric design.
During experiments, researchers explored different strategies to improve WBG movies. Among these, the direct addition of Peai to the precursor solution as a direct additive (from) and the introduction of Peai in the anti -Violent as a process additive (spa). In addition, another spa variant included a mixture of Mai and Peai in a 1: 2 ratio, creating a local environment full of ma.
Stability tests have shown that samples containing but have maintained over 85% of the initial efficiency for 500 hours. However, the samples without cations but have shown better performance. “Future studies should focus on non-ma additives to further improve the formation of 2D templates,” the researchers underlined.
The team plans to apply this technology on an industrial level, optimizing long-term efficiency and stability for large-scale applications, both residential and utility-scales. Among the objectives, there is the creation of larger devices through the method of Blade Coatinga scalable and economically advantageous technique:
We are focusing on the optimization of parameters such as the composition of the solvent, the deposition speed, the annealing conditions and the uniformity of the coating to ensure constant quality of the film on larger substrates.
The group is also studying advanced characterization techniques to better understand how the scalability process affects the crystallicity, the orientation and the overall morphology of the films in Perovskite.
The global race to overcome the efficiency limits
Reducing the costs of solar energy and improving the efficiency of photovoltaic panels represents a crucial challenge for a sustainable future. Although the team of the University of Nanchino has achieved an extraordinary result with the tandem cells entirely in Perovskite, they are not the only protagonists of this technological revolution.
Further progress arrives from China, as shown by the innovation of the Tandem Perovskite-Silicio cell Developed by scientists of the Polytechnic University of the North-West of Xi’an, in the province of Shaanxi. This four terminal cell, semi-transparent, integrates an advanced protective layer of Indio oxide (in₂o₃)which not only improves efficiency but is also produced through a low -cost method and solveless. An approach, therefore, more sustainable and easily scalable for large -scale production.
International competition does not stop here to overcome the limits of photovoltaic efficiency. The Chinese company Longi recently reached anrecord efficiency of 33.9% with silicon-perovskite tandem cells, overcoming the theoretical limit of for the first time Shockley-Queisser 33.7% for single junction cells. This milestone opens new possibilities for energy efficiency and productivity on a global scale.
Also Oxford PVin collaboration with the Fraunhofer Institute, made it talk about itself by announcing an efficiency of the 25% For its tandem solar panels of Perovskite on silicon. Thanks to this innovation, Oxford PV has consolidated its role in the transformation of the photovoltaic sector.
The future of renewable energy is getting closer, and with each new efficiency record we approach a cleaner and more competitive global energy system.
