Droplet-vaporization behavior during plasma-assisted mist chemical vapor deposition of zinc oxide films

Droplet vaporization behavior during plasma-assisted mist chemical vapor deposition of zinc oxide films was investigated. The time required for a droplet to fully evaporate is simulated as a function of the initial droplet temperature, droplet-vapor interactions, and initial droplet size. Droplets injected into the plasma are vaporized by the heat flux from the plasma. It was found that micrometric size droplets evaporate completely within several microseconds due to heat flux from the plasma. Moreover, owing to differences in vaporization rates, solid particles were formed from some of the droplets during their passage through the plasma, but other droplets formed incomplete particles or remained as droplets due to incomplete evaporation. Particles formed in the plasma and subsequently deposited on a substrate maintained their shape.