Indoor energy harvesting enhancement: Pb-free perovskite solar cell with nanograting contactDaniel Sarcanean, Ángela Barreda, Eduardo López-Fraguas, Iván Mora-Seró, Antonio García-Martín, Braulio García-Cámara and Ricardo VergazJ. Eur. Opt. Society-Rapid Publ., 22 1 (2026) 38DOI: https://doi.org/10.1051/jeos/2026031