Light emitting device including tandem structure

A light emitting device comprising:

• a pair of electrodes;
• two or more light emitting elements disposed between the electrodes in a stacked arrangement, wherein each of the two or more light emitting elements comprises a layer comprising an emissive material, wherein the emissive material included in each of the two or more light emitting elements comprises quantum dots, and wherein the layers included in the two or more light emitting elements emit light of a same color;
• and
• a charge generation element disposed between adjacent light emitting elements in the stacked arrangement, the charge generation element comprising a first layer comprising nanoparticles of an inorganic n-type semiconductor material and a second layer comprising a hole injection material;
• where the nanoparticles of the inorganic n-type semiconductor material are in direct contact with at least one layer of the emissive material.