Photophysics of polycyclic aromatic hydrocarbons adsorbed on silica gel surfaces. 1. Fluorescence lifetime distribution analysis: an ill-conditioned problem

The ill-conditioned nature of the lifetime distribution analysis is demonstrated using the fluorescence decay data of pyrene adsorbed on variously dehydroxylated silica gel surfaces. A set of physically plausible results can be obtained only after a regularization technique is employed in the data reduction. This study indicates that a bimodal distribution appears to be suitable for describing the lifetime of pyrene adsorbed on a silica gel surface