  The mechanical properties of Cadmium Selenide (CdSe) nanowire is an emerging
issue due to its application in semiconductor and optoelectronics industries.
In this paper, we conducted molecular dynamics (MD) simulations to investigate
the temperature-dependent mechanical properties and failure behavior of
Zinc-Blende (ZB) CdSe nanowire under uniaxial tensile deformation. We employed
Stillinger-Weber (SW) potential to describe the inter-atomic interactions. The
effect of variation of temperatures (100 K-600 K), sizes, and crystal
orientation on the tensile response of the CdSe nanowires is investigated. Our
simulation results suggest that both ultimate tensile strength and Youngs
modulus of CdSe have an inverse relationship with temperature. From 100K to
600K, the ZB CdSe exhibits brittle type failure thus there is no brittle to
ductile transition temperature found. Results also suggest that size has a
significant effect on the mechanical properties of CdSe nanowire. It has been
found that as the cross-sectional area increases both ultimate tensile stress
and Youngs modulus increases as well. The [111] oriented ZB CdSe shows the
largest ultimate tensile strength, Youngs modulus and fracture toughness
whereas the values are lowest for [100] orientation. The [110] orientation
shows the largest failure strain compared to other orientations. Finally,
failure mechanisms of CdSe nanowire are also investigated at 100K and 600K. We
noticed that at 100K temperature [100] oriented ZB CdSe fails along {111}
cleavage plane however in the case of 600 K temperature, both {111} and {100}
planes are activated and cause fracture of CdSe nanowire at lower strain value.
This study can guide to design ZB CdSe based solar cell, optoelectronic and
semiconductor devices by presenting a comprehensive understanding of the
mechanical and fracture characteristics of this nanowire.
