Samsung patents quantum dot screen layer for better light control

1. A quantum dot device, comprising a first electrode and a second electrode, a light emitting layer between the first electrode and the second electrode, the light emitting layer comprising quantum dots, and a first hole auxiliary layer between the first electrode and the light emitting layer, wherein the first hole auxiliary layer comprises a first hole auxiliary material, and a second hole auxiliary material having a greater bandgap energy than a bandgap energy of the first hole auxiliary material, wherein a difference between a highest occupied molecular orbital energy level of the second hole auxiliary material and a highest occupied molecular orbital energy level of the first hole auxiliary material is 0.1 electronvolts to less than 0.8 electronvolts, a difference between a lowest unoccupied molecular orbital energy level of the second hole auxiliary material and a lowest unoccupied molecular orbital energy level of the first hole auxiliary material is greater than or equal to 0.3 electronvolts, the highest occupied molecular orbital energy level of the second hole auxiliary material is less than the highest occupied molecular orbital energy level of the first hole auxiliary material, the highest occupied molecular orbital energy level of the first hole auxiliary material is 5.1 electronvolts to 5.6 electonvolts, the lowest unoccupied molecular orbital energy level of the second hole auxiliary material is less than the lowest unoccupied molecular orbital energy level of the first hole auxiliary material, the first hole auxiliary layer comprises less of the second hole auxiliary material than the first hole auxiliary material on a mole basis, each of the first hole auxiliary material and the second hole auxiliary material is a polymer semiconductor, the second hole auxiliary material comprising the polymer semiconductor comprising a triphenylamine moiety, and the lowest unoccupied molecular orbital energy level of the second hole auxiliary material is 1.2 electronvolts to 2.0 electronvolts.