Light-emitting device, electronic device, and lighting device
摘要
說明書
Note that between the reflective electrode and the EL layer 103, a transparent electrode layer can be formed as an optical distance adjustment layer with use of a conductive material having a light-transmitting property, and the first electrode 101 can consist of the reflective electrode and the transparent electrode. With the transparent electrode layer, the optical distance (cavity length) of the microcavity structure can be also adjusted. Examples of the conductive material having a light-transmitting property include metal oxides such as indium tin oxide (hereinafter referred to as ITO), indium tin oxide containing silicon or silicon oxide (abbreviation: ITSO), indium oxide-zinc oxide (indium zinc oxide), indium oxide-tin oxide containing titanium, indium titanium oxide, and indium oxide containing tungsten oxide and zinc oxide.
The transflective electrode has a visible light reflectivity of 20% to 80%, preferably 40% to 70%, and a resistivity of 1×10?2 Ωcm or lower. The semi-transmissive semi-reflective electrode can be formed using one or more kinds of conductive metals and alloys, conductive compounds, and the like. Specifically, a metal oxide, such as indium tin oxide (hereinafter referred to as ITO), indium tin oxide containing silicon or silicon oxide (ITSO), indium oxide-zinc oxide (indium zinc oxide), indium oxide-tin oxide containing titanium, indium-titanium oxide, or indium oxide containing tungsten oxide and zinc oxide, can be used. A metal thin film having a thickness that allows transmission of light (preferably, a thickness greater than or equal to 1 nm and less than or equal to 30 nm) can also be used. As the metal, Ag, an alloy of Ag and Al, an alloy of Ag and Mg, an alloy of Ag and Au, an alloy of Ag and Yb, or the like can be used.
