US Patent 9793505 Light-emitting device including quantum dots

A light emitting device including an emissive material comprising quantum dots is disclosed. In one embodiment, the device includes a cathode, a layer comprising a material capable of transporting and injection electrons comprising an inorganic material, an emissive layer comprising quantum dots, a layer comprising a material capable of transporting holes, a layer comprising a hole injection material, and an anode. In certain embodiments, the hole injection material can be a p-type doped hole transport material. In certain preferred embodiments, quantum dots comprise semiconductor nanocrystals. In another aspect of the invention, there is provided a light emitting device wherein the device has an initial turn-on voltage that is not greater than 1240/λ, wherein λ represents the wavelength (nm) of light emitted by the emissive layer. Other light emitting devices and a method are disclosed.