Effect of Stress-Dependent Thermal Conductivity on Thermo-Mechanical Coupling Behavior in GaN-Based Nanofilm Under Pulse Heat Source

The thermal properties of a nanostructured semiconductor are affected by multi-physical fields, such as stress and electromagnetic fields, causing changes in temperature and strain distributions. In this work, the influence of stress-dependent thermal conductivity on the heat transfer behavior of a GaN-based nanofilm is investigated. The finite element method is adopted to simulate the temperature distribution in a prestressed nanofilm under heat pulses. Numerical results demonstrate the effect of stress field on the thermal conductivity of GaN-based nanofilm, namely, the prestress and the thermal stress lead to a change in the heat transfer behavior in the nanofilm. Under the same heat source, the peak temperature of the film with stress-dependent thermal conductivity is significantly lower than that of the film with a constant thermal conductivity and the maximum temperature difference can reach 8.2 K. These results could be useful for designing GaN-based semiconductor devices with higher reliability under multi-physical fields.