演  講  者：方得華 國立高雄科技大學機械系講座教授兼系主任

組       別：全體組別

演講時間：2021-03-15　13：30　

演講地點：MEA401演講廳

演講摘要：

In this study, we use molecular dynamics to investigate the thermal conductivity and mechanical properties of quintuple layers of nanofilms with different effects. The results indicate that the Bi2Te3 nanofilm perfect substrate has the ideal Young’s modulus and thermal conductivity and show a strong temperature dependence of the thermal conductivity for Bi2Te3 nanofilms with an ideal structure. As the interface changed, the structural disorder of atomic arrangement affected the mechanical properties; moreover, the phonons encounter lattice disordered atomic region will produce scattering reduce heat conduction. We also verified the self-assembly mechanism for nanoscale Bi2Te3 and found that the Bi2Te3–Te interface induces strong phonon scattering. We characterized their mechanical properties by nanoindentation and in situ transmission electron microscopy (TEM). The nanoindentation results revealed that a significant ‘pop-in’ phenomenon occurs under high-loading conditions with multiple dislocations and phase transitions in the material structure. The results of this study may be useful for optimizing thermoelectric devices in the future.