Organic light emitting device

An organic light emitting device comprising:

• a first electrode;
• a second electrode;
• an emissive layer disposed between the first electrode and the second electrode;
• a first hole injection layer disposed between the first electrode and the emissive layer;
• a second hole injection layer disposed between the first hole injection layer and the emissive layer, comprising a second hole injecting material;
• and
• a first electron transport layer disposed between the emissive layer and the second electrode,
• the first hole injection layer comprising a hole injecting material and a first compound comprising an element selected from the group consisting of Mo, Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr, Ba, ytterbium and B and an element selected from the group consisting of O, F, S, Cl, Se, Br, and I,
• the second hole injecting material being at least one selected from the group consisting of copper phthalocyanine, 1,3,5-tricarbazolylbenzene, 4,4′-biscarbazolylbiphenyl, polyvinylcarbazole, m-biscarbazolylphenyl, 4,4′-biscarbazolyl-2,2′-dimethylbiphenyl, 4,4′,4″-tri(Ncarbazolyl) triphenylamine (TCTA), 4,4′,4″-tris(3-methylphenylamino)triphenylamine (m-MTDATA), 1,3,5-tri (2-carbazolylphenyl) benzene, 1,3,5-tris(2-carbazolyl-5 methoxyphenyl)benzene, bis(4-carbazolylphenyl)silane, N,N′-bis(3-methylphenyl)-N,N′diphenyl-[1, 1-biphenyl]-4,4′-diamine (TPD), N,N′-di(naphthalene-1-yl)-N,N′-diphenyl benzidine (α-NPD), N,N′-diphenyl-N,N′-bis(1-naphthyl)-(1, 1′-biphenyl)-4,4′-diamine (NPB), poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenylamine) (TFB), and poly(9,9-dioctylfluorene-co-bis-N, N-phenyl-1,4-phenylenediamine (PFB),
• a thickness ratio of the first hole injection layer to the second hole injection layer being in a range of 1:99 to 1:9, and
• the first electron transport layer comprising a first electron transporting material and a second compound, the second compound represented by Formula 1 below:
• XaYb <Formula 1>
• wherein:
• X is an alkali metal, an alkali earth metal, or a transition metal,
• Y is a group 7 element, or acetoacetate,
• a is a number in the range of 1 to 3, and
• b is a number in the range of 1 to 3,
• an amount of the second compound in the first electron transport layer being in a range of 30 to 50 parts by weight based on 100 parts by weight of the first electron transporting material.