Multimodal Photoluminescence Imaging of Halide Perovskite Materials and Solar Cells

Dr. Stefania Cacovich

CNRS – UMR 9006, Institut Photovoltaique d’Ile de France (IPVF), Palaiseau, France

Photovoltaic devices enable the direct conversion of light into electricity, playing a crucial role in achieving climate targets and advancing a low-carbon economy. In the solar cell community, there is growing interest in optical imaging techniques—particularly luminescence-based methods—as powerful, contactless, and non-destructive tools for probing device performance across their entire lifecycle, from material growth to operando operation. These methods are applicable to a range of technologies, including emerging halide perovskites, organic solar cells, II–V compounds, and silicon. I will discuss how quantitative photoluminescence imaging advances our understanding of the opto-electronic properties of halide perovskites, bridging the gap between fundamental material characteristics and device-level performance. Key strategies explored include efficiency enhancement, scalable fabrication, and stability improvement, with special emphasis on interfacial passivation using organic cations to suppress non-radiative recombination and enhance charge transport[1]. Beyond single-junction devices, I will present recent progress in tandem architectures combining perovskites with complementary photovoltaic technologies such as CIGS and organic solar cells. PL imaging enables detailed analysis of layer uniformity and sub-cell interactions in these complex systems. Finally, to overcome limitations of noisy and time-consuming time-resolved fluorescence imaging (TR-FLIM), we developed an unsupervised deep-learning framework combining Noise2Noise training with physics-driven modelling. This method reconstructs high-quality lifetime maps from short acquisitions, reducing sample degradation while enabling precise extraction of parameters such as bulk and surface recombination rates.

1.             Cacovich, S., Vidon, G., Degani, M., Legrand, M., Gouda, L., Puel, J.-B., Vaynzof, Y., Guillemoles, J.-F., Ory, D., and Grancini, G. (2022) Imaging and quantifying non-radiative losses at 23% efficient inverted perovskite solar cells interfaces. Nat Commun, 13 (1), 2868.