Abstract: A novel display device that is highly convenient with low power consumption is provided. The display device includes a display element including a liquid crystal layer, a display element including a light-emitting layer, and a pixel circuit. Electrodes of the display element including the liquid crystal layer and the display element including the light-emitting layer are electrically connected to the pixel circuit. The electrode of the display element including the liquid crystal layer includes a reflective film including an opening. The pixel circuit includes a transistor including a semiconductor film. The number of insulating films in a region overlapping with the opening is smaller than that of insulating films overlapping with the semiconductor film. In addition, the display element including the light-emitting layer includes two light-emitting elements.

Abstract: Provided is a novel display device that is highly convenient or reliable or a display device with low power consumption and high display quality. The display device includes a first pixel and a second pixel. The first pixel and the second pixel are adjacent to each other. Each of the first pixel and the second pixel includes a first display region and a second display region. The first display region is configured to reflect incident light. The second display region is positioned inside the first display region and configured to emit light. A position of the second display region inside the first display region in the first pixel and a position of the second display region inside the first display region in the second pixel are different from each other.

Abstract: A technique of manufacturing a display device with high productivity is provided. In addition, a high-definition display device with high color purity is provided. By adjusting the optical path length between an electrode having a reflective property and a light-emitting layer by the central wavelength of a wavelength range of light passing through a color filter layer, the high-definition display device with high color purity is provided without performing selective deposition of light-emitting layers. In a light-emitting element, a plurality of light-emitting layers emitting light of different colors are stacked. The closer the light-emitting layer is positioned to the electrode having a reflective property, the shorter the wavelength of light emitted from the light-emitting layer is.

Abstract: A light-emitting element having high external quantum efficiency is provided. A light-emitting element having a long lifetime is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains at least a phosphorescent compound, a first organic compound (host material) having an electron-transport property, and a second organic compound (assist material) having a hole-transport property. The light-emitting layer has a stacked-layer structure including a first light-emitting layer and a second light-emitting layer, and the first light-emitting layer contains a higher proportion of the second organic compound than the second light-emitting layer. In the light-emitting layer (the first light-emitting layer and the second light-emitting layer), a combination of the first organic compound and the second organic compound forms an exciplex.

Abstract: A novel light-emitting device is provided. A novel light-emitting device with high emission efficiency, low power consumption, and small viewing angle dependence of chromaticity is provided. The light-emitting device includes at least one light-emitting element and one optical element. A spectrum of light emitted from the light-emitting element through the optical element in a range of greater than 0° and less than or equal to 70° with respect to a normal vector of the light-emitting element has a first local maximum value in a wavelength range of greater than or equal to 400 nm and less than 480 nm and a second local maximum value located on a longer wavelength side than the first local maximum value. The intensity ratio of the second local maximum value to the first local maximum value is less than or equal to 15%.

Abstract: A light-emitting element disclosed includes a first electrode layer; a second electrode layer which transmits light; and a light-emitting layer interposed between the first electrode layer and the second electrode layer. The first electrode layer includes a first conductive layer which is able to reflect light, a second conductive layer provided over the first conductive layer and including titanium, and a third conductive layer which transmits light and contains a metal oxide having work function higher than that of a material of the first conductive layer.

Abstract: Provided is a light-emitting device which can emit monochromatic light with high purity due to a microcavity effect and which can emit white light in the case of a combination of monochromatic light. Provided is a high-definition light-emitting device. Provided is a light-emitting device with low power consumption. In a light-emitting device with a white-color filter top emission structure, one pixel is formed of four sub-pixels of RBGY, an EL layer includes a first light-emitting substance which emits blue light and a second light-emitting substance which emits light corresponding to a complementary color of blue, and a semi-transmissive and semi-reflective electrode (an upper electrode) is formed so as to cover an edge portion of the EL layer.

Abstract: Disclosed is a light-emitting element with a microcavity structure which is capable of amplifying a plurality of wavelengths to give emission of a desired color. The light-emitting element includes a pair of electrodes and an EL layer having a light-emitting substance interposed between the pair of electrodes. One of the pair of electrodes gives a reflective surface and the other electrode gives a semi-reflective surface. The light-emitting element is arranged so that the emission of the light-emitting substance covers at least two wavelengths ? and an optical path length L between the reflective surface and the semi-reflective surface satisfies an equation L=n?/2 where n is an integer greater than or equal to 2.

Abstract: A technique of manufacturing a display device with high productivity is provided. In addition, a high-definition display device with high color purity is provided. By adjusting the optical path length between an electrode having a reflective property and a light-emitting layer by the central wavelength of a wavelength range of light passing through a color filter layer, the high-definition display device with high color purity is provided without performing selective deposition of light-emitting layers. In a light-emitting element, a plurality of light-emitting layers emitting light of different colors are stacked. The closer the light-emitting layer is to the electrode having a reflective property, the longer the wavelength of light emitted from the light-emitting layer is.

Abstract: Emission efficiency of a light-emitting element is improved. The light-emitting element has a pair of electrodes and an EL layer between the pair of electrodes. The EL layer includes a first light-emitting layer and a second light-emitting layer. The first light-emitting layer includes a fluorescent material and a host material. The second light-emitting layer includes a phosphorescent material, a first organic compound, and a second organic compound. An emission spectrum of the second light-emitting layer has a peak in a yellow wavelength region. The first organic compound and the second organic compound form an exciplex.

Abstract: A tandem light-emitting element employing an inverted-structure is provided. The light-emitting element includes a cathode, a first EL layer over the cathode, a second EL layer over the first EL layer, an anode over the second EL layer, and an intermediate layer. The intermediate layer is between the first EL layer and the second EL layer. The intermediate layer includes a first layer, a second layer over the first layer, and a third layer over the second layer. The first layer includes a hole-transport material and an electron acceptor. The third layer includes an alkali metal or an alkaline earth metal. The second layer includes an electron-transport material.

Abstract: A light-emitting element with which a reduction in power consumption and an improvement in productivity of a display device can be achieved is provided. A technique of manufacturing a display device with high productivity is provided. The light-emitting element includes an electrode having a reflective property, and a first light-emitting layer, a charge generation layer, a second light-emitting layer, and an electrode having a light-transmitting property stacked in this order over the electrode having a reflective property. The optical path length between the electrode having a reflective property and the first light-emitting layer is one-quarter of the peak wavelength of the emission spectrum of the first light-emitting layer. The optical path length between the electrode having a reflective property and the second light-emitting layer is three-quarters of the peak wavelength of the emission spectrum of the second light-emitting layer.

Abstract: A light-emitting element having high external quantum efficiency is provided. A light-emitting element having a long lifetime is provided. A light-emitting layer is provided between a pair of electrodes. The light-emitting layer is a stack of a first light-emitting layer, which contains at least a first phosphorescent compound, a first organic compound having an electron-transport property, and a second organic compound having a hole-transport property and is provided on the anode side, and a second light-emitting layer, which contains at least a second phosphorescent compound and the first organic compound having an electron-transport property. A combination of the first organic compound and the second organic compound forms an exciplex.

Abstract: A technique of manufacturing a display device with high productivity is provided. In addition, a high-definition display device with high color purity is provided. By adjusting the optical path length between an electrode having a reflective property and a light-emitting layer by the central wavelength of a wavelength range of light passing through a color filter layer, the high-definition display device with high color purity is provided without performing selective deposition of light-emitting layers. In a light-emitting element, a plurality of light-emitting layers emitting light of different colors are stacked. The closer the light-emitting layer is to the electrode having a reflective property, the longer the wavelength of light emitted from the light-emitting layer is.

Abstract: A technique of manufacturing a display device with high productivity is provided. In addition, a high-definition display device with high color purity is provided. By adjusting the optical path length between an electrode having a reflective property and a light-emitting layer by the central wavelength of a wavelength range of light passing through a color filter layer, the high-definition display device with high color purity is provided without performing selective deposition of light-emitting layers. In a light-emitting element, a plurality of light-emitting layers emitting light of different colors are stacked. The closer the light-emitting layer is positioned to the electrode having a reflective property, the shorter the wavelength of light emitted from the light-emitting layer is.

Abstract: A light-emitting element having high external quantum efficiency is provided. A light-emitting element having a long lifetime is provided. A light-emitting element includes a light-emitting layer between a pair of electrodes. The light-emitting layer contains at least a phosphorescent compound, a first organic compound (host material) having an electron-transport property, and a second organic compound (assist material) having a hole-transport property. The light-emitting layer has a stacked-layer structure including a first light-emitting layer and a second light-emitting layer, and the first light-emitting layer contains a higher proportion of the second organic compound than the second light-emitting layer. In the light-emitting layer (the first light-emitting layer and the second light-emitting layer), a combination of the first organic compound and the second organic compound forms an exciplex.

Abstract: A light-emitting element with which a reduction in power consumption and an improvement in productivity of a display device can be achieved is provided. A technique of manufacturing a display device with high productivity is provided. The light-emitting element includes an electrode having a reflective property, and a first light-emitting layer, a charge generation layer, a second light-emitting layer, and an electrode having a light-transmitting property stacked in this order over the electrode having a reflective property. The optical path length between the electrode having a reflective property and the first light-emitting layer is one-quarter of the peak wavelength of the emission spectrum of the first light-emitting layer. The optical path length between the electrode having a reflective property and the second light-emitting layer is three-quarters of the peak wavelength of the emission spectrum of the second light-emitting layer.

Abstract: A novel light-emitting device is provided. A novel light-emitting device with high emission efficiency, low power consumption, and small viewing angle dependence of chromaticity is provided. The light-emitting device includes at least one light-emitting element and one optical element. A spectrum of light emitted from the light-emitting element through the optical element in a range of greater than 0° and less than or equal to 70° with respect to a normal vector of the light-emitting element has a first local maximum value in a wavelength range of greater than or equal to 400 nm and less than 480 nm and a second local maximum value located on a longer wavelength side than the first local maximum value. The intensity ratio of the second local maximum value to the first local maximum value is less than or equal to 15%.

Abstract: Provided is a light-emitting device which can emit monochromatic light with high purity due to a microcavity effect and which can emit white light in the case of a combination of monochromatic light. Provided is a high-definition light-emitting device. Provided is a light-emitting device with low power consumption. In a light-emitting device with a white-color filter top emission structure, one pixel is formed of four sub-pixels of RBGY, an EL layer includes a first light-emitting substance which emits blue light and a second light-emitting substance which emits light corresponding to a complementary color of blue, and a semi-transmissive and semi-reflective electrode (an upper electrode) is formed so as to cover an edge portion of the EL layer.

Abstract: A light-emitting element with improved heat resistance is provided without losing its advantages such as thinness, lightness, and low power consumption. A light-emitting element is provided which includes a first electrode, a second electrode, and an EL layer between the first electrode and the second electrode, in which the EL layer includes a layer containing a condensed aromatic compound or a condensed heteroaromatic compound, and a layer containing 2,9-bis(naphthalen-2-yl)-4,7-diphenyl-1,10-phenanthroline (abbreviation: NBPhen) in contact with the layer containing the condensed aromatic compound or the condensed heteroaromatic compound.