Organic electroluminescent devices: enhanced carrier injection using an organosilane self assembled monolayer (SAM) derivatized ITO electrode

摘要: A protocol for the reproducible silylation of indium–tin oxide coated glass (ITO) using small molecule chlorosilanes is reported, and shown to be a convenient means dramatically improving performance ITO anode invariable used in organic electroluminescent devices. Using model system: ITO|TPD|Alq3|Al (where TPD N,N′-bis(3-methylphenyl)-N,N′diphenyl-1,1′biphenyl-4,4′-diamine Alq3 tris(quinolin-8-olato)aluminium) luminance-voltage, current–voltage, quantum efficiency luminance data illustrate superior silane modified device over reference. Static contact angle measurements confirming successful electrode surface, are supported by direct measurement effect dipolar monolayer has on work function underlying ITO, scanning Kelvin probe. This research builds our earlier with phosphonic acids. However, unlike acids, known adhere surfaces via covalent bond, so silylated electrodes expected exhibit improved durability. Such modification provides method tuning HOMO hole-transporting layer thus, performance.