OLED device with buffer layer adjacent light emitting layer

An OLED device comprising a light emitting unit between an anode and a cathode, the light emitting unit comprising:

• a first carrier function layer for migration of first carriers, the first carrier function layer comprising a first carrier injecting layer, a first carrier transporting layer and a first material layer having a first material, wherein the first material comprises a first blocking material for blocking second carriers, and the first carrier injecting layer comprises a material of Dipyrazino[2,3-f:2′,3′-h]quinoxaline-2,3,6,7,10,11-hexacarbonitride;
• the second carrier function layer for migration of second carriers having a polarity different from that of the first carriers, the second carrier function layer comprising a second carrier injecting layer, a second carrier transporting layer and a second material layer having a second material, wherein the second material comprises a second blocking material for blocking the first carriers;
• a light emitting layer between the first material layer and the second material layer, the light emitting layer comprising a luminescent material of 2-methyl-9, 10-bis(naphthalen-2-yl)anthracene doped with 1-4-di[4-(N,N-diphenyl)amino]styryl-benzene, wherein doping ratio is about 3%;
• a first buffer layer between the light emitting layer and the first material layer, the first buffer layer being a mixed layer containing the luminescent material and the first material, wherein thickness of the first buffer layer is about 1 nm, and percentage by mass of the luminescent material in the first buffer layer is about 10%;
• and
• a second buffer layer between the light emitting layer and the second material layer, the second buffer layer being a mixed layer containing the luminescent material and the second material, wherein thickness of the second buffer layer is about 1 nm, and percentage by mass of the luminescent material in the second buffer layer is about 10%.