Organic light emitting display device having layer to control charge transfer

An organic light emitting display device, comprising:

• an anode on a substrate;
• a first emission part on the anode, the first emission part including a first hole transfer layer, a first emission layer, and a first electron transfer layer;
• a second emission part on the first emission part, the second emission part including a second hole transfer layer, a second emission layer, and a second electron transfer layer;
• an N-type charge generation layer between the first emission part and the second emission part;
• and
• a cathode on the second emission part,
• wherein at least one among the first emission part and the second emission part comprises an emission control layer having an absolute value of a highest occupied molecular orbital (HOMO) energy level which is larger than an absolute value of a HOMO energy level of the first hole transfer layer or the second hole transfer layer,
• wherein at least one among the first electron transfer layer and the second electron transfer layer includes at least two materials that are mixed through co-deposition,
• wherein a first material of the at least two materials has an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level within a first range of 2.91 eV to 3.40 eV and a second material of the at least two materials has an absolute value of a lowest unoccupied molecular orbital (LUMO) energy level within a second range of 2.60 eV to 2.90 eV,
• wherein the first range and the second range do not overlap,
• wherein the first electron transfer layer comprises one among the at least two materials, and the second electron transfer layer comprises the at least two materials, and
• wherein a difference between a LUMO energy level of the first electron transfer layer and a LUMO energy level of the N-type charge generation layer is 0.50 eV to 1.00 eV.