Quantum dot device and electronic device comprising an emissive quantum dot and a non-emissive quantum dot

A quantum dot device including an anode and a cathode facing each other, a quantum dot layer disposed between the anode and the cathode, and an electron transport layer disposed between the cathode and the quantum dot layer, wherein the quantum dot layer includes an emissive quantum dot emitting light in at least one part of a wavelength region in a visible region and a non-emissive quantum dot configured to not emit light in a visible region, and a difference between a lowest unoccupied molecular orbital (LUMO) energy level of the non-emissive quantum dot and a LUMO energy level of the electron transport layer is greater than or equal to about 0.5 electronvolts (eV).