APPLICATIONS OF TECHNOLOGY:
- Biological imaging
- Electronics production
- Catalyst production
- Photonic band gap materials
- Mechanical structural support in polymer films
- High-surface-area catalysts
- Can synthesize whole branched inorganic nanocrystals with well-defined connectivities in three dimensions
Researchers in Paul Alivisatos’s lab at Berkeley Lab have developed a way to create branched inorganic nanocrystals, including tetrapods (with 4 arms), branched tetrapods (with branches on the four arms), and inorganic dendrimers (which look like snowflakes). All these structures are made by the same principle used to make semiconductor nanocrystals, or quantum dots. The material used for these branched nanocrystals is CdSe, but in practice similar structures can be made with any crystal with both cubic and hexagonal modifications that are close-lying in energy, such as all II-VI and III-V semiconductors, and numerous metals such as Ni and Co.
Inorganic nanocrystals possess optical, electric, magnetic, catalytic, and mechanical properties that can be widely tuned by varying their size and shape, as with quantum dots. By synthesizing inorganic nanocrystals of specific shapes, one can combine their electrical and optical properties with structural properties afforded by their unique shapes. The work of Alivisatos and colleagues represents the first time that a method has been demonstrated to prepare whole branched inorganic nanocrystals with well-defined connectivities in three dimensions.
Potential applications include electron transport, photovoltaics, LCDs, orientation of nanocrystals, photonic band gap materials, providing mechanical structural support in polymer films, biological imaging, and high-surface-area catalysts. These nanocrystals could expand the possible range of devices that could be built from nanocrystal blocks in the future. For example, when tetrapods are dropped on a surface, they always land on three arms with the fourth arm pointing straight up. This should be a useful feature for the wiring of nanosized electronic devices.
STATUS: Issued U. S. Patents 6,855,202; 7,311,774; 8,062,421; 8,608,848. Available for licensing in some fields of use
REFERENCE NUMBER: IB-1773
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