Charge Manipulation and Exploratory Devices Research Thrust

Effective exploitation of the unique properties of nanostructured materials in solar energy conversion, especially in using multiple excitons or "hot electrons," is contingent on our ability to efficiently extract and transport carriers to charge-collecting electrodes. To this end, the Charge Manipulation and Exploratory Devices Thrust explores charge separation and transport, as well as energy transfer, in engineered nanoassemblies.

Specific research topics include extraction of multiple charges, exciton transport in extended gradient structures, and the effects of semiconductor-metal interaction on energy transfer. This thrust also includes research into prototype Generation-III devices that demonstrate enhanced power conversion efficiency through use of novel nanoscale physics and novel architectures. These exploratory devices are specifically designed to harness the physical principles found in both discrete and simple extended structures and are used to elucidate key phenomena endemic to sequential increases in complexity, e.g., in progressing from a simple nanocrystal film to a multilayer device.

Architectures Using Nano-Enhanced Phenomena

Activities in this area:

Illustration of a five-layered cell. The top layer is a thin gold back contact, then a 70-nanometer-thick layer of spherical lead selenide quantum dots, then a 120-nanometer-thick layer of spherical zinc oxide nanocrystals, then a 150-nanometer-thick layer of indium tin oxide, and a bottom layer of glass.

Solar cell architecture for enhancing electricity generation phenomena using nanometer-scale layers of quantum dots and nanocrystals.

Novel Hybrid Architectures

Activities in this area:

Charge Separation in Engineered Type-II Nanostructures

Although experimentally useful, recently demonstrated core-shell type-II structures are not well-suited for photovoltaic applications because of difficulties in extracting the charges located in the core. Therefore, activities in this area:

This work involves close interactions between synthetic chemists, theorists, and spectroscopists.