Enhanced field emission of silicon tips coated with sol-gel-derived (Ba0.65Sr0.35)TiO3 thin film

Enhanced field emission of silicon emitter arrays coated with (Ba0.65Sr0.35)TiO3 (BST) thin film has been investigated by varying annealing temperature and thickness of sol-gel BST coatings. The results indicate that the BST coatings exhibit the perovskite structure while annealed between 650 and 700 DGC, and an interfacial reaction occurs between silicon and BST coating while annealed above 750 DGC. The BST-coated silicon tips show considerable improvement in electron emission. The emission behavior is highly correlated to the crystallinity of BST layer, and the turn-on field could be lowered substantially from 38 V/mm for bare silicon tips to about 12 V/mm for BST coated silicon tips annealed at 700 DGC. The thickness of BST coatings and interface reaction at Si/BST interface also affect the emission behaviors significantly. Analysis of the emission data using Fowler-Nordheim plots suggests that the improvement in electron emission originates from the lowering of work function with BST coatings.