Comment on "Metal-organic green dye: chemical and physical insight into a modified Zn-benzoporphyrin for dye-sensitized solar cells" by G. Zanotti, N. Angelini, G. Mattioli, A. M. Paoletti, G. Pennesi, G. Rossi, D. Caschera, L. de Marcoc and G. Giglide, , 2016, , 5123.

The emission spectroscopy and photophysics reported in the title paper are shown to be untenable in light of previously reported experimental results and widely accepted theories of electronic excited state relaxation. The published results strongly suggest that the newly synthesized dye is contaminated with one of more highly fluorescent impurities.