The effect of size-dependent thermal characteristics on transient heat transport in one/quasi-one dimensional materials

In this research, a phenomenological nonlocal dual-phase lag model has been used to investigate heat transfer in nanoscale MOSFET transistors. In addition to considering the phase lag parameters and nonlocal effects, the dependence of thermal properties on the system size has also been examined. Due to the change in the phonon mean free path when switching from bulk to thin-film material, this parameter plays an important role in determining thermal properties. Quasi-one-dimensional materials such as titanium trisulfide and indium selenide, along with the one-dimensional carbon nanotubes have been studied as the potential replacements for silicon in transistor channels. The results showed that, despite the similarity in the peak temperature achieved by the titanium trisulfide, indium selenide, and silicon, the heat propagation rate is higher in silicon with higher thermal conductivity, allowing it to reach a steady state faster. On the other hand, carbon nanotubes exhibit a lower peak temperature. For quasi-one-dimensional titanium trisulfide and indium selenide, heat transfer is slower, necessitating thermal spreaders. Considering the size-dependent thermal properties, temperature and heat flux decrease along the entire channel, This temperature reduction is more significant in carbon nanotubes and silicon material, which have a larger phonon mean free path. The reason is the direct impact of increasing this parameter on the changes in the effective mean free path and thermal conductivity. These results highlight the importance of simultaneously considering nonlocal effects, phase lag, and size-dependent thermal properties to achieve accurate temperature and heat distribution results within transistors.