Molecular Photovoltaic Systems Based on Phospholipids/Alkanethiol Hybrid Bilayer Membranes: Photocurrent Generation and Modulation

Abstract

Biological membranes offer an ideal place to assemble necessary components for plant photosynthesis in nature and suggest new strategies to build artificial photosynthetic systems by using lipid bilayers. In this dissertation, we develop a novel artificial photovoltaic system based on a hybrid bilayer membrane (HBM). The hybrid bilayer membrane is composed of a self- assembled monolayer (SAM) of alkanethiols on Au substrate and another monolayer of palmitoyloleoyl-phosphatidylcholine (POPC) phospholipids. The structure of the hybrid bilayer membrane is characterized by cyclic voltammetry (CV), quartz crystal microbalance (QCM) and impedance spectroscopy. We observe the photocurrent generation by incorporating either ruthenium tris(bipyridyl) complexes (Ru(bpy)3 2+ ) or monomalonic fullerenes (C63) as photoagents with the hybrid bilayer membrane. By modifying SAM with functionalized alkanthiols, we could modulate the photocurrent and photovoltage. The photocurrent generation and electron transfer mechanisms of this new system provide potential usefulness in the fundamental photoconversion study.