A light emitting device including a first electrode and a second electrode facing each other, a blue fluorescent light emitting layer and a non-blue phosphorescent light emitting layer in contact with each other between the first electrode and the second electrode, a first common layer between the first electrode and the non-blue phosphorescent light emitting layer, and a second common layer between the blue fluorescent light emitting layer and the second electrode. The non-blue phosphorescent light emitting layer includes a first host, and a first dopant having a first triplet excitation level and a first singlet-triplet excitation level difference. The blue fluorescent light emitting layer includes a second dopant having: a second singlet-triplet excitation level difference that is smaller than the first singlet-triplet excitation level difference, and a second triplet excitation level that is higher than the first triplet excitation level, and a second host.

Embodiments of the disclosed subject matter may provide a display device or display surface including at least one emissive layer and a near-infrared (NIR) emissive layer disposed in a stack arrangement between a first electrode and a second electrode, where NIR light is emitted from the NIR emissive layer through the at least one emissive layer, or visible light is emitted from the at least one emissive layer through the NIR emissive layer, and where the NIR light output by the NIR emissive layer has a peak wavelength of 740 nm-1000 nm. Embodiments of the disclosed subject matter may provide a near infrared (NIR) light source disposed behind or in front of an active-matrix organic light emitting diode (AMOLED), where the NIR light source has an area greater than 25% of an active area of the display device or display surface.

A light emitting device including a first electrode and a second electrode facing each other, and a first blue stack, a first charge generation layer, and a phosphorescent stack disposed between the first electrode and the second electrode. The phosphorescent stack includes a hole transport layer, a red light emitting layer, a green light emitting layer, and an electron transport layer. The red light emitting layer includes an electron transport host represented by Formula 1, a hole transport host different from the hole transport layer, and a red dopant.

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A white light emitting device, or more particularly an inverted white light emitting device, includes a plurality of stacks configured to emit white light, and an optical compensation layer provided at an outer surface of an electrode through which light is emitted to the outside. The configuration reduces the thickness of an electron transport layer adjacent to a cathode in the stack and therefore reduces the driving voltage and improves the viewing angle characteristics and as well as the efficiency.

Discussed is a light-emitting device that can include a first electrode and a second electrode facing each other, and disposed on a substrate; a first light emitting stack and a second light emitting stack between the first electrode and the second electrode; and a charge generation stack between the first light emitting stack and the second light emitting stack. The charge generation stack can include a first layer including a first host, a second host, and a metal dopant, and a second layer including the first host, the metal dopant, a third host, and a p-type organic dopant. Amounts of the metal dopant in the first layer and the second layer respectively can increase in going towards an interface between the first layer and the second layer.

A light emitting display device can include a light emitting diode structure disposed on a substrate and having a first sub-pixel, a second sub-pixel, a third sub-pixel and a fourth sub-pixel, a bank that defines a pixel area of each of the first sub-pixel, the second sub-pixel, the third sub-pixel and the fourth sub-pixel, and a function improving unit disposed on the first emission part, the second emission part, the third emission part, the fourth emission part and the bank. One or two of sub-pixel among the first to fourth sub-pixels include a tandem emission part in which a first emission unit including a first emission layer and a second emission unit disposed on the first emission unit and including a second emission part are laminated.

Disclosed is a display device including a substrate at an exit side, first to third color subpixels provided on the substrate, each of the color subpixels having a thin film transistor, first to third color filters provided respectively at the first to third color subpixels, first to third anodes provided respectively on the first to third color filters so as to be connected to the thin film transistors, an emission unit commonly provided at the first to third color subpixels on the first to third anodes, the emission unit including at least two blue fluorescent stacks and two phosphorescent stacks, and a cathode provided on the emission unit, wherein the first to third color subpixels constitute a basic unit, and a third color subpixel of an n-th basic unit neighbors a first color subpixel of an (n+1)-th basic unit in the same row or column on the substrate.

Disclosed is a light emitting display device configured to have a structure in which an auxiliary conversion portion including color conversion layers having different transmission characteristics and overlapping each other is applied to a non-emission portion of a subpixel, whereby luminous efficacy is improved and current-density-specific color purity is equalized, and therefore image quality is improved.

Discussed is an organic light emitting display device capable of achieving an enhancement in blue characteristics while having subpixels having a same size by designing a blue one of the subpixels using a hole only device (HOD) structure. The blue subpixel can include two blue emission material layers stacked to form the HOD structure. The blue subpixel can driven using two data lines and two driving transistors so that the two blue emission material layers alternately emit light on a frame basis.

An organic light emitting display device can include a display panel including a plurality of data lines and a plurality of scan lines intersecting each other, and unit pixels disposed in a matrix arrangement, each of the unit pixels being disposed in a region where one scan line intersects three data lines; a data driving circuit configured to drive the plurality of data lines; and a gate driving circuit configured to drive the plurality of gate lines. Also, each of the unit pixels comprises two subpixels, and each of the two subpixels has a structure in which red, green and blue light emitting elements are stacked.