Eectroluminescence in nano-porous titania films

We report room-temperature electroluminescence in a solid-state hetero-junction device using a nano-porous titania film as active material. A broad defect-related luminescence band covering all of the visible range and centered at 600 nm is observed. Electrons are injected from an n-type polymer layer, while hole injection occurs from a conductive SnO2substrate. The polymer films form a highly non-planar interface with strongly enlarged area to the TiO2nano-pore structure. This type of interface establishes very short current paths to the recombination region and allows high carrier fluxes from the electron-injecting contact.