Dye type solar cells, especially those incorporating low cost dyes suffer from a very narrow photo-response wavelength range. Motivated by natural photosynthesis research, energy relay dyes (ERDs) appear to offer a possibility to broaden the dye-cell spectral response. In-turn photovoltaic cells can be an extremely sensitive tool for investigation of dye ERD photochemistry. Sensitive Chlorophyll based dye-type solar cells were prepared from purified natural Chlorophyll A. The importance of Chlorophyll purity is discussed as well as the use of purified Chlorophyll A in combination with ERD’s. . Results shed light on many interesting phenomenon including the nature of purified Chlorophyll A excitation and absorption. Importantly, it was found by this work that the ERD architecture when combined with a photosensitizer do not appear to having greater absorption in the infrared region of the spectrum than the ERD alone indicating a lack of cooperative absorption.