A study by researchers from São Paulo State University (UNESP) has produced results that could significantly benefit the future of the solar energy industry. In the article published in Materials Chemistry C JournalBrazilian researchers describe a strategy to improve the efficiency and stability of solar cells made from perovskite, a laboratory-grown semiconductor material. The results of the project could be very positive for the future of the solar energy industry.

The method, developed by researchers at São Paulo State University (UNESP) in Bauru, Brazil, involves the use of a class of materials known as MXenes, a two-dimensional family of materials with a graphene-like structure that combines transition metals. carbon and/or nitrogen and surface functional groups such as fluoride, oxygen or hydroxyl. Its properties include high electrical conductivity, good thermal stability, and high transmittance (referring to the amount of light that passes through a material without being reflected or absorbed).

In MXene Ti study₃C.₂T_X Polymethyl methacrylate (PMMA) was added to create a spin-coated passivating coating on the perovskite layer of inverted solar cells. Passivation coatings are designed to reduce possible defects in polycrystalline solids (in this case perovskite) resulting from interaction with the environment or their internal structure. Perovskite solar cells have a layered structure, and the order (architecture) of the layers is critical to their performance. In an inverted solar cell, the architecture of the device is changed to allow high optical transparency when sunlight reaches the perovskite layer.

Improved efficiency and stability

Ti Application₃C.₂T_X It increased the power conversion efficiency of the elements from 19% to 22%. It also increased the stability of the cells, which lasted three times longer without loss of performance compared to control cells (no passivation layer).

For João Pedro Ferreira Assunção, first author of the paper and a master’s candidate in the UNESP Materials Science and Technology master’s program, the results were surprising because the main aim of the project was simply to correct the drop in performance. Addition of an insulating passivation layer.

Research on perovskite solar cells is currently focused on how to develop large-scale industrial production systems to produce stable, high-performance cells. “This paper demonstrates that MXene addition may be possible in a mass production setting and demonstrates a way to achieve this. It also describes a variety of electrical, morphological and structural characterization techniques that we are investigating to advance scientific understanding of how this complex class of devices behaves and works.” said Assuncão.

He added that the research is a promising step towards the goals of sustainable development of clean energy production, reducing environmental impact and making Brazil a leading industrial producer of solar cells.