In the present work, our films were encapsulated in a layer of clear plastic tape for the emission measurements. This encapsulation most likely significantly reduces the light power input and emission from the films, as indicated by the relatively low emission intensity of the control sample (0% Ni 2+ ). Therefore, the complete quenching effect we observe in even the lowest concentration (1% Ni 2+ ) samples is most likely an overestimation of the actual quenching capability of Ni 2+ in this system. Additionally, these materials displayed significant moisture sensitivity, with color changes from black to light brown/clear in a matter of seconds on exposure to moisture. Given this, we speculate that these materials are highly sensitive to changes in sample preparation and relative measurement conditions.