INVESTIGATION OF DENDRIMERS AS LIGHT HARVESTING AGENTS

Abstract

Dendritic molecules are well suited materials for trapping photon energy, which can be converted back to visible light. Their tree-like structure acts as an energy gradient for the funneling of energy while their periphery provides large absorbing units, resulting in high probability of photon capture and the closeness of the periphery to the core makes energy transfer highly efficient. Using dendritic molecular samples from a Michigan-based company – Dendritic Nano-Technology (DNT), spectroscopic techniques were used to investigate the light harvesting properties of dendrimers. Pure dye samples dissolved in alcohol were mixed with dendrimers. The mixture was excited with 1064 nm Nd:YAG laser and the resulting fluorescent signal collected. Preliminary investigation shows that while dendrimers themselves do not produce fluorescence, they act as suitable encapsulating agents for dye molecules.  arising from the 3-photon absorption that resulted in the enhancement of dye fluorescence. Furthermore, while stilbene dye could produce fluorescence by direct 3-photon absorption, other dyes species like BDN and Q5 needed the dendrimer environment for enhanced fluorescence activities, while other dyes like LDS 765 showed a tendency towards lasing at low laser energy. This encapsulating feature suggests that dendrimers have possible application in the production of drug capsules