The development of temperature in target ablation of pulsed laser deposition of ZnO thin film

The whole ablation process of target ZnO heated by pulsed laser was studied.The ablating model of a bulk target irradiated by a pulse laser was set up.Under the appropriate dynamic boundary conditions,the heat flow equation with heat generation term,and the temperature distribution of target before and after the melting were studied in detail.The results showed that before the melting,at a fixed location,the temperature increased with the ablation time.The less the heat diffusion distance was,the faster the variety rate of the temperature was.At the same time,in different location,the temperature decreased gradually along with the increase of the heat diffusion distance.Using the combination of analytical method and integral-approximation method,and solving the heat flow equation,the temperature distribution of solid and liquid phases's functions of time and location were obtained.The temperature grad of liquid phases decreased with the increase of the heat diffusion distance.Within 0.5 micron distance from the ablation surface,the temperature grad of liquid phases was great;beyond 0.5 micron,the variety rate of the temperature became very slow;while the temperature distribution of solid phases was more complex.