Materials and devices for photovoltaic energy conversion

Sustainable, renewable energy production has become one of the most pressing issues in science, politics and society. Disappearing polar ice caps, record world oil prices, soaring gasoline prices and instabilities in natural gas supplies in Eastern Europe only underscore the need for sustainable, carbon-neutral, secure sources of energy. Further complicating the situation, most commercial products, such as silicon solar cells, and near-commercial technologies, such as fuel cells and dye-sensitized solar cells, are either far too energy intensive in their production or utilize scarce precious metals, such as platinum, as electrode catalysts. Both raise questions concerning the viability and sustainability of the present incarnations of the technologies. Top researchers throughout the world are promoting the concept of energy harvesting technologies that use only earth-abundant materials. The goal of the proposed research is to develop materials systems and device structures for photovoltaic energy production using commonly available, low-cost materials which are compatible with low-temperature, thereby energy conserving, sustainable manufacturing techniques. The applicant's long-term and current research in organic electronic materials and devices, including photovoltaic applications, and recent efforts in the fields of transparent inorganic metal oxide semiconductors, dye-sensitized solar cells and growth of multi-walled carbon nanotubes on electrode surfaces has created a unique opportunity, where these areas of expertise can be combined to yield new, potentially ground-breaking approaches to solar energy conversion.Two parallel approaches to advance the state of the art in thin-film photovoltaic materials and technologies are proposed: p-i-n doped organic solar cells to greatly enhance charge separation and decrease internal resistive losses, and the development of new hybrid organic/inorganic solar cells using high electron mobility, wide bandgap binary metal oxide semiconductors as the electron acceptor and transport layer.