Peidong Yang

One-dimensional (1D) nanostructures are of both fundamental and technological interest. They not only exhibit interesting electronic and optical properties intrinsically associated with their low dimensionality and the quantum confinement effect, but also represent the critical components in the potential nanoscale device applications. With the ever-decreasing sizes of these 1D nanostructures, the "bottom-up" chemical approach is playing increasing role due to its capability of making much smaller features as compared to the "top-down" approach. Major challenge, however, remains in order to fully exploit the 1D nanostructures, namely, the development of suitable chemical strategies for the rational synthesis, organization and integration of these nanoscale building blocks.

The Yang research group is interested in the synthesis of new classes of materials and nanostructures with an emphasis on developing new synthetic approaches and understanding the fundamental issues of structural assembly and growth that will enable the rational control of material composition, micro/nano- structure, property and functionality. We are putting together a nanoscale toolbox where nanowires of different compositions and properties (metal, semiconductor) will be used as building blocks in our continuing efforts in miniaturizing optoelectronic devices. For example, semiconductor (Si, Ge, ZnO, GaN) nanowires are being synthesized using chemical vapor deposition/transport. Significant effort has also been placed on investigating the novel physical properties of the nanowire building blocks. Particularly we are interested in the thermoelectrical, photovoltaic and optoelectronic properties. Due to their high surface area, low-dimensionality and potential quantum confinement, many new physical properties are expected. These novel properties serve as the basis for miniaturized devices such as laser, photovoltaics, thermoelectrics and solar-to-fuel conversion systems.