Anisotropic energy and electron migration in multichromophore-laden polymers on metal surfaces

Anisotropic orientation of chromophores on metals and metal oxide surfaces can be attained by self-assembly of oriented dyes bearing appropriate surface recognition functionality. For example, chromophore-laden polymers can be bound to gold either by polymerizing a chosen monomer onto a surface-bound trithiol ''seed'' or by direct binding a pre-formed organic polymer terminated with a thiol functional group. Efficient light harvesting is accomplished when multiple chromophores are covalently attached to one or more segments of a multiblock copolymer. Photophysical measurements of exciton mobility and of electron transfer efficiency will be described, along with the effect of molecular architecture on the suppression of charge recombination via back electron transfer.