A research group led by Professor Dong Suk Kim ofUNISTATE SCHOOL OF CARBON NEUTRALITYin collaboration with the Professor Tae Kyung Lee ofNational University of Gyeongsang (GNU)he developed one Solar cell in Perovskite (PSC) capable of resisting extreme conditions of heat and humidity, opening the road to large -scale marketing of this technology.
The solar cells in Perovskite, considering the heirs of the current silicon cells, offer higher theoretical efficiency And lower production costs. However, theirs poor heat resistance He has so far limited the commercial diffusion. Unlike silicon cells, in fact, the PSC do not tolerate encapsulation temperatures above 110 ° C, necessary to prevent humidity and oxygen from compromising its structure.
To overcome this limit, the researchers replaced the traditional additive 4-terz-butilpiridine (TBP) with Carbonate ethylene (EC) In the gap transport layer (Hole Transport Layer, HTL). Although the TBP better the initial efficiency, greatly lowers the Vetrosa transition point (TG) of the material, making it unstable beyond 80 ° C. The EC, on the contrary, allowed to Raise the TG up to 125 ° Cgiving greater thermal resistance and structural stability to the cell.
Efficiency of 25.56% and unprecedented durability in extreme conditions
The result was extraordinary: the new PSC has reached an initial efficiency of 25.56%the highest ever recorded for Solar cells without TBP. But even more surprising it was the Resistance to extreme environmental conditions. After prolonged exposure to 85 ° C of temperature And 85% of relative humidity for 1,000 hoursthe cell has maintained an efficiency of the 21.7%keeping over 85% of the initial performance.
Even after the intrapsialation process, which simulates the real conditions of use, the efficiency has remained substantially unchanged. And that’s not all: when technology has been applied to a 100 cm² modulethe cell has maintained excellent efficiency of the 22.14%confirming the System scalability.
These results have been made possible by the ability of theEthyl carbonate to uniformly dissolve the doping Litio bis (trifluoromoromansulfonil) inexperienced)significantly improving the transport of charges to the gap transport layer and thus contributing to the overall efficiency of the device.
A decisive step towards the marketing of the PSC
Professor Kim stressed the importance of innovation:
Thanks to this study, we have developed a system for the transport of charges that maintains high performance even in environments at high temperature and humidity. This discovery represents a crucial step towards the practical application of solar cells in Perovskite.
The research was published in the scientific journal Energy & Environmental Scienceconfirming the value of the discovery on the international panorama of clean energy.
