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 °C, and an interfacial reaction occurs between silicon and BST coating while annealed above 750 °C. 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/μm for bare silicon tips to about 12 V/μm for BST-coated silicon tips annealed at 700 °C. 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.