Perovskite solar cells (PSCs) have long been attracting attention due to their high power conversion efficiency and low-cost solution processing. However, ensuring their stability at high temperatures has been a challenge because the contact points ("interfaces") between their different layers are prone to degradation, leading to energy loss and performance degradation.

In a new study led by the Swiss Federal Institute of Technology in Lausanne (EPFL), scientists have found that they can minimize the degradation of PSCs at high temperatures by using fluorinated aniline, a compound used in pharmaceuticals, agrochemicals and materials science. The latest research results have been recently published in the "Science" magazine.

Specifically, the researchers added fluorinated aniline during the "interface passivation" step of PSC fabrication. "Interfacial passivation" is a technique used to enhance the stability and performance of interfaces between different layers or materials to reduce defects, reduce charge recombination, and improve overall efficiency and stability.

The addition of fluorinated aniline avoids ligand intercalation and improves the stability of PSCs, the researchers explained. This prevents the continuous permeation of ligand molecules between the layers or structures of the perovskite material, thereby destroying the integrity of the crystals and leading to the degradation and performance degradation of PSCs.

It is reported that using this method, the researchers achieved a quasi-conversion power efficiency of 24.09% for the inverted structure PSC. Moreover, in tests at a temperature of 85°C, a relative humidity of 50%, and 1 solar luminosity (the intensity of the sun at noon under normal conditions), the device continued to operate at maximum power generation for 1560 hours (approximately 65 days) while maintaining its functionality and efficiency.

According to the researchers, this study makes a significant contribution to the stability of PSCs and provides potential solutions for improving their performance, durability, and reliability in high-temperature environments, bringing people closer to terawatt-scale applications of this promising photovoltaic technology.