Effect of annealing temperature on the electron emission characteristics of silicon tips coated with Ba_0.67Sr_0.33TiO₃ thin film

Electron emission from an array of silicon tips coated with BST ferroelectric thin film was systematically studied by varying the sol-gel BST annealing temperature from 650 to 800°C. It was found that a higher annealing temperature tends to result in a reduction of effective work function and thus enhanced the electron emission characteristic. The reduction of effective work function was a result of higher activation of ionic conduction, which increases carrier concentration and raises the Fermi level toward the conduction band. In addition, it was found that BST film annealed at 750°C has relatively lower electron trap density than other cases. Lower electron trap density may be responsible for the relatively high emission efficiency.