Pardon me if this has already been posted. We used several of these for lasers and also absorption targets when we were working on optical spectroscopy for cancer detection. All of these dyes are stable and the concentrations, secondary emissions and extinction coefficients are available. The question that comes to mind is how to efficiently go about trying these as spectral sensitizers in an emulsion. It looks like it could take a long time.

http://www.exciton.com/wavelength_chart.html