October 31, 2003

Striped Nanowires

Source:  Peidong Yang

References:

Heterojunctions or superlattices are semiconductor "sandwiches" where different semiconductors are grown in alternating layers.  This allows the semiconductor to be customized for a specific application.  They are very important elements of modern semiconductor devices, especially for optical applications such as LEDs (light-emitting diodes) and lasers.  They are also very useful in specific electronics applications like cell phones and other communications devices. 

As we approach the nanoscale, heterojunction and superlattice formation is essential for many potential applications of semiconductor nanowires in nanoscale optoelectronics. A hybrid pulsed laser ablation/chemical vapor deposition (PLA-CVD) process has been developed for the synthesis of semiconductor nanowires with longitudinal ordered heterostructures. The laser ablation process generates a programmable pulsed vapor source, which enables the nanowire growth in a block-by-block fashion with a well-defined compositional profile along the wire axis. Single-crystalline nanowires with a longitudinal Si/SiGe (Silicon/Silicon-Germanium) superlattice structurea have been successfully synthesized. This unique class of heterostructured one-dimensional nanostructures holds great potential in applications such as light emitting devices and thermoelectrics.