In collaboration with scientists from Italy, two researchers from CINE have developed perovskite solar cells that exhibit excellent performance in transforming artificial light into electricity in indoor environments. These devices could provide clean and renewable energy for appliances used in homes, businesses, or industries, without the need for batteries.

The indoor photovoltaic market was valued at approximately $1.2 trillion in 2023. However, indoor environments, with their low light levels, represent a challenge for conventional photovoltaic technologies, because they sharply drop the device efficiency.

In this work, the authors managed to overcome this challenge through the development of an innovative surface treatment for the perovskite layer. “Under indoor lighting conditions (1000 lux, 500 lux, and 200 lux), our treatment substantially reduces interfacial trapping states, allowing for a performance of around 34% for low-bandgap perovskite modules. This performance is among the efficiency records reported in the literature,” says Francineide Lopes de Araújo, postdoctoral researcher at CINE and lead author of the work.

The treatment consists of depositing a mixture of the organic salt PEAI with the additive DIO onto the perovskite layer. As a result, a two-dimensional perovskite layer spontaneously forms over the three-dimensional perovskite, neutralizing its surface defects and improving its performance. The process takes place at room temperature; that is, the PEAI:DIO layer does not undergo any heat treatment after its deposition. “The PEAI:DIO mixture improves defect passivation, optimizes interfacial dipole alignment, and enhances charge transport; for this reason, it was possible to obtain high-performance devices,” specifies Francineide.

This strategy was employed in the fabrication of devices at different scales, from small-area solar cells to large-area modules, up to 121 cm2, formed by up to 15 subcells connected in series.

“The developed strategy demonstrates strong competitive potential in relation to other production methodologies for perovskite solar cells and modules, especially in terms of manufacturing simplicity and low cost impact,” says the postdoctoral researcher, who developed the work under the supervision of Professor Ana Flávia Nogueira (Unicamp) and Professor Aldo Di Carlo, founder and researcher of the Center for Hybrid and Organic Solar Energy (CHOSE) of the Università degli Studi di Roma Tor Vergata (Italy).

CHOSE is one of the world’s leading research centers for perovskite photovoltaic devices, and has a complete infrastructure for the fabrication and characterization of cells, modules, and panels.

The collaboration took place during Francineide’s postdoctoral research internship in Rome between 2022 and 2023, with support from FAPESP through a grant for research internship abroad named BEPE. According to the postdoctoral researcher, the center’s infrastructure was essential for conducting advanced experiments and validating the developed devices.

The results of this research reinforce the applicability of perovskite-based photovoltaic technology, enabling its use in low-power electronic devices used in indoor environments. “The technological advances achieved in this work contribute to making perovskite solar cells more viable for commercial-scale application,” concludes Francineide.

The research was funded by FAPESP and Shell, with strategic support from ANP, and resources from European agencies.

Paper reference: Francineide Lopes de Araujo, Maurizio Stefanelli, Antonio Agresti, Sara Pescetelli, Alessia Di Vito, Matthias Auf Der Maur, Luigi Vesce, Ana Flavia Nogueira, Aldo Di Carlo. Empowering perovskite modules for solar and indoor lighting applications by 1,8-diiodooctane/phenethylammonium iodide 2D perovskite passivation strategy. Nano Energy. Volume 142, Part B, September 2025, 111279. https://doi.org/10.1016/j.nanoen.2025.111279.

CINE members who participated in the work: Francineide Lopes de Araujo (postdoctoral researcher) and Ana Flávia Nogueira (director and researcher).