High efficiency quantum dot LED structure

A light-emitting device maximizes optical efficiency when the emissive layer is high refractive index material. Said device includes an emissive layer; a first electrode and a second electrode from which charges are generated; a first charge transport layer that injects charges from the first electrode into the emissive layer; and a second charge transport layer that injects charges from the second electrode into the emissive layer. A Fresnel reflection value at boundaries between the emissive layer and at least one of the first and second charge transport layers is from 5% through 30%, and at least one of the charge transport layers satisfies a half wavelength condition of having a thickness that is equal to within twenty percent of ½ of one wavelength of an integer multiple of ½ of one wavelength in the charge transport layer material within a bandwidth of emission of the emissive layer.