Humidity effect on the evolution of CsI thin films: a fractal study of rough surfaces Nabeel Jammal, R. P. Yadav, Richa Rai, Triloki, Alok Pandey, A. K. Mittal and B. K. Singh Eur. Phys. J. Plus, 138 6 (2023) 516 Published online: 10 June 2023 DOI: 10.1140/epjp/s13360-023-04139-2