Novel Mechanical Properties of Compound Semiconductor Nanowires:
As part of developing processes for the large-scale assembly of nanowires, we have studied the mechanical behavior of thin Zn3P2 nanowires. Our experimentation indicated that the mechanical properties of nanowires are dependent on their diameters. While thick Zn3P2 nanowires break on application of stress, thin nanowires bend elastically on application of stress and recover back to their original shape after the removal of the applied stress (see the videos provide below). Such elasticity in compound semiconductor nanowires has never been reported. This elastic nature is crucial to prevent grain growth during the large-scale assembly of nanowires into highly dense pellets and to extend any novel properties observed in thin nanowires to large-scale assemblies of nanowires.
(The section below describes how we have employed this phenomenon for achieving enhanced thermoelectric properties in bulk nanowire assemblies.)
This is a video showing the brittle nature of thick single-crystalline Zinc Phosphide nanowire. Thicker nanowires show similar mechanical properties of bulk Zinc Phosphide.
A video showing the elastic nature of thin (<50nm) single-crystalline Zinc Phosphide nanowire. Thinner single-crystalline nanowires show elastic nature as opposed to the brittle nature of bulk Zinc Phosphide.