CAMBRIDGE, Mass., Feb. 12 -- Methods for controlling the composition and charge of multiple materials on a single nanostructure are described in a paper in the Feb. 7 issue of Nature, "Growth of Nanowire Superlattice Structures for Nanoscale Photonics and Electronics." Charles Lieber, Nanosys Inc. cofounder and the Mark Hyman Professor of Chemistry at Harvard University and graduate students Mark Gudiksen, Lincoln Lauhon, Jianfang Wang and David Smith wrote the paper, which Nanosys described as landmark research. "The researchers take advantage of the flexible control of multiple variables to build novel devices in electronics, photonics and opto-electronics," Nanosys said. "Lieber's work is the first example of a generic method for creating heterojunctions of arbitrary materials in a single nanostructure."
Lieber's technique also allows the modulation of doping levels along the length of a single nanowire. This ability to control charge and composition on the nanoscale enabled the Lieber group to make a variety of unique prototype devices, such as GaAs emitters embedded in GaP wires, novel n-Si/p-Si nanowire diodes for high-density nanoscale logic and nanometer-size LEDs derived from alternating segments of n-InP/p-InP on a single nanowire.
"This robust synthetic method allows for the creation of superlattice heterostructures of materials that cannot be interfaced in macroscopic structures. This could open the door to the discovery of new materials and devices for a semiconductor industry that faces the impending limit to Moore's law," according to Nanosys.
Nanosys is a new company focused on developing nanotechnology-enabled systems that incorporate novel and patent-protected zero and one-dimensional nanometer-scale materials such as nanowires, nanotubes and nanodots (quantum dots) as their principal active elements.