Molecular Dynamics Simulation Of Thermal Conductivity Of Zinc Oxide Thin Films

Zinc oxide thin film is a wide bandgap compound semiconductor material,which has a wide range of applications in optoelectronic devices,piezoelectric devices,solar cells,gas sensors and other fields.Since the thermal conductivity will directly affect the thermal performance of micro-nano devices,which will affect the performance and stability of the device,the thermal conductivity of thin-film materials is of great significance for thermal analysis,thermal management,and optimal design of micro and nano devices.It is difficult and inaccurate to measure the thermal conductivity of micro/nano thin films experimentally.Therefore,the use of molecular dynamics simulation method to study the thermal conductivity of the film has become a very effective means,but also can overcome some practical problems that are difficult to solve in the experiment,while reducing the capital and manpower investment.In this paper,the non-equilibrium molecular dynamics simulation method was used to select the microcanonical ensemble.Using the Buckingham potential function,the thermal conductivity of the wurtzite-type zinc oxide film and the zinc blende-type zinc oxide film was simulated at 300 K temperature.The simulation results show that when the thickness of the wurtzite-type zinc oxide film is between 15.593 nm and 31.2096 nm,the thermal conductivity of the film is in the range of 0.870575-1.1619 KmW)/(?;the thickness of the zincate-type zinc oxide film is 6.89055nm-13.8356 nm.Its thermal conductivity is between 11.16612 and 16.17671 KmW)/(?.The calculated data of the two structures are separately plotted.According to the image,the thermal conductivity of both structures of zinc oxide films increases with the increase of the film thickness.From the simulation results,it can be seen that the calculated results of the zinc oxide thin films of the two structures are significantly smaller than the experimental values of the corresponding bulk zinc oxide,that is,they have a size effect.According to the aerodynamic theory,the generated size effect is analyzed.When the simulated film thickness is within ten nanometers,the phonon mean free path is no longer equal to the phonon mean free path of its bulk,but related to the simulated film thickness.The research findings in this paper provide useful references for thermal design and thermal management of microelectronic devices.And it provides some reference value for people to use molecular dynamics method to simulate the thermal conductivity of zinc oxide thin film.