A team of researchers from the University of California, Berkeley, has made a major advance in understanding how nanowires form. The team, led by Professor Peidong Yang, used a combination of experimental and theoretical techniques to study the growth of silicon nanowires. Their findings, published in the journal Nature, provide new insights into the fundamental mechanisms that govern nanowire formation.

Nanowires are tiny, one-dimensional structures that have a wide range of potential applications in electronics, optics, and other fields. However, their growth and control have been limited by our understanding of the underlying physics.

The Berkeley team's breakthrough came when they realized that the growth of silicon nanowires is controlled by a competition between two opposing forces: surface energy and elastic energy. Surface energy is the energy associated with the surface of the nanowire, while elastic energy is the energy associated with the deformation of the nanowire's crystal structure.

When the surface energy is high, the nanowire will tend to grow in a smooth, cylindrical shape. However, when the elastic energy is high, the nanowire will tend to grow in a faceted shape, with flat sides and sharp edges.

The researchers found that the balance between surface energy and elastic energy can be controlled by the growth conditions. By varying the temperature, pressure, and composition of the growth environment, they were able to grow silicon nanowires with a variety of different shapes and sizes.

The team's findings provide a new framework for understanding the growth of nanowires. This framework will enable researchers to design and grow nanowires with the desired properties for specific applications.

The ability to control the growth of nanowires is a major step forward in the development of nanotechnology. Nanowires are expected to play a key role in future technologies, such as advanced electronics, solar cells, and medical devices.

Reference

Peidong Yang et al. "Competition between surface energy and elastic energy in silicon nanowire growth." Nature 456, 218 (2008).