Abstract: Provided is a light-emitting device which can emit monochromatic lights with high color purity due to a microcavity effect and which can provide a white light with a broad spectrum when the monochromatic lights are combined. The light-emitting device has a red-, green-, blue-, and yellow-emissive light-emitting elements each of which has a reflective electrode and a semi-transmissive and semi-reflective electrode. The red-, green-, blue-, and yellow-emissive light-emitting elements have the same structure other than the reflective electrode and a layer in contact with the reflective electrode to selectively emit red, green, blue, and yellow lights, respectively. Red, green, and blue color filters are also provided over the red-, green-, blue-, light-emitting elements, respectively. An EL layer is commonly shared by the red-, green-, blue-, and yellow-emissive light-emitting elements, and the semi-transmissive and semi-reflective electrode covers an edge portion of the EL layer.

Abstract: To provide a light-emitting element with low drive voltage. The light-emitting element includes a first electrode, a second electrode, and an EL layer. The first electrode includes a first conductive layer and a second conductive layer including a region in contact with the first conductive layer. The first conductive layer has a function of reflecting light, and the second conductive layer has a function of transmitting light. The second conductive layer includes an oxide containing In and M (M represents one or more of Al, Si, Ti, Ga, Y, Zr, La, Ce, Nd, and Hf). The EL layer includes an organic acceptor material in a region in contact with the second conductive layer.

Abstract: To provide a display device with low power consumption. The display device includes a plurality of pixels each having a light-emitting element having a structure in which light emitted from a light-emitting layer is resonated between a reflective electrode and a light-transmitting electrode, wherein no color filter layers are provided or color filter layers with high transmittance are provided in pixels for light with relatively short wavelengths (e.g., pixels for blue and/or green), and a color filter layer is selectively provided in pixels for light with a long wavelength (e.g., pixels for red), and thereby maintaining color reproducibility and consuming less power.

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: To provide a novel light-emitting element or a novel light-emitting device with high emission efficiency and low power consumption, a light-emitting element having a plurality of light-emitting layers between a pair of electrodes includes a lower electrode, a first light-emitting layer over the lower electrode, a charge-generation layer over the first light-emitting layer, a second light-emitting layer over the charge-generation layer, and an upper electrode over the second light-emitting layer. An emission spectrum of the first light-emitting layer peaks at a longer wavelength than an emission spectrum of the second light-emitting layer. A distance of between a bottom surface of the upper electrode and a bottom surface of the first light-emitting layer is less than or equal to 130 nm.

Abstract: A light-emitting device includes a first light-emitting element emitting blue light, a second light-emitting element emitting green light, and a third light-emitting element emitting red light. A first reflective electrode and a first transparent conductive film, a second reflective electrode and a second transparent conductive film, and a third reflective electrode and a third transparent conductive film are stacked in the first to third light-emitting elements, respectively. A first light-emitting layer, a charge-generation layer, a second light-emitting layer, and an electrode are stacked in this order over each of the first transparent conductive film, the second transparent conductive film, and the third transparent conductive film. The electrode has functions of transmitting and reflecting light. The first to third reflective electrodes contain silver. The first transparent conductive film is thicker than the third transparent conductive film.

Abstract: A light-emitting element includes a cathode, an anode, a light-emitting layer, a first layer, a second layer, and a third layer. The first layer is provided between the cathode and the light-emitting layer. The second layer is provided between the light-emitting layer and the third layer and includes a region in contact with the third layer. The third layer is provided between the second layer and the anode and includes a region in contact with the anode. The first layer and the third layer each include an alkali metal or an alkaline earth metal. The second layer includes a material that has a function of transporting an electron.

Abstract: A light-emitting panel includes at least a first and a second light-emitting elements, each light-emitting element having, between a reflective film and a semi-transmissive/semi-reflective film, a layer including an optical adjustment layer and a light-emitting organic compound. One of the light-emitting elements further includes a layer transmitting red light provided over the corresponding semi-transmissive/semi-reflective film. The layer having the organic compound emits light having a wavelength between 600 nm and 800 nm, and light having a wavelength between 400 nm and 600 nm. The distance between the reflective film and the semi-transmissive/semi-reflective film in one of and the other one of the light-emitting elements are N/2 (where N is a natural number) of a length between 600 nm and 800 nm, and N/2 of a length between 400 nm and 600 nm, respectively.

Abstract: One object of this invention is to provide a novel light-emitting device with low power consumption. The light-emitting device includes a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first electrode, a second electrode, and a light-emitting layer. The second light-emitting element includes the first electrode, a third electrode, and the light-emitting layer. The second electrode comprises only a first conductive film, and the third electrode comprises a second conductive film and a third conductive film. The first electrode has a function of reflecting light. The second conductive film has functions of reflecting light and transmitting light. The first conductive film and the third conductive film each have a function of transmitting light.

Abstract: To provide a novel light-emitting device, a light-emitting device that emits light of a plurality of colors includes a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first lower electrode, a first light-emitting layer over the first lower electrode, a second light-emitting layer over the first light-emitting layer, and an upper electrode over the second light-emitting layer. The second light-emitting element includes a second lower electrode, the first light-emitting layer over the second lower electrode, the second light-emitting layer over the first light-emitting layer, and the upper electrode over the second light-emitting layer. An emission spectrum of the first light-emitting layer peaks at a longer wavelength than an 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: Provided is a light-emitting device which can emit monochromatic lights with high color purity due to a microcavity effect and which can provide a white light with a broad spectrum when the monochromatic lights are combined. The light-emitting device has a red-, green-, blue-, and yellow-emissive light-emitting elements each of which has a reflective electrode and a semi-transmissive and semi-reflective electrode. The red-, green-, blue-, and yellow-emissive light-emitting elements have the same structure other than the reflective electrode and a layer in contact with the reflective electrode to selectively emit red, green, blue, and yellow lights, respectively. Red, green, and blue color filters are also provided over the red-, green-, blue-, light-emitting elements, respectively. An EL layer is commonly shared by the red-, green-, blue-, and yellow-emissive light-emitting elements, and the semi-transmissive and semi-reflective electrode covers an edge portion of the EL 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: To provide a display device with low power consumption. The display device includes a plurality of pixels each having a light-emitting element having a structure in which light emitted from a light-emitting layer is resonated between a reflective electrode and a light-transmitting electrode, wherein no color filter layers are provided or color filter layers with high transmittance are provided in pixels for light with relatively short wavelengths (e.g., pixels for blue and/or green), and a color filter layer is selectively provided in pixels for light with a long wavelength (e.g., pixels for red), and thereby maintaining color reproducibility and consuming less power.

Abstract: To provide a novel light-emitting element or a novel light-emitting device with high emission efficiency and low power consumption, a light-emitting element having a plurality of light-emitting layers between a pair of electrodes includes a lower electrode, a first light-emitting layer over the lower electrode, a charge-generation layer over the first light-emitting layer, a second light-emitting layer over the charge-generation layer, and an upper electrode over the second light-emitting layer. An emission spectrum of the first light-emitting layer peaks at a longer wavelength than an emission spectrum of the second light-emitting layer. A distance of between a bottom surface of the upper electrode and a bottom surface of the first light-emitting layer is less than or equal to 130 nm.

Abstract: An electrode layer having high reflectance and a light-emitting element having high emission efficiency are provided. The light-emitting element includes a first electrode layer, a second electrode layer, and an EL layer between the first electrode layer and the second electrode layer. The first electrode layer includes a conductive layer and an oxide layer in contact with the conductive layer. The conductive layer has a function of reflecting light. The oxide layer includes In and M (M represents Al, Si, Ti, Ga, Y, Zr, Sn, La, Ce, Nd, or Hf). A content of the M in the oxide layer is higher than or equal to a content of the In.

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 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, a first transistor, and a second transistor. The first transistor is electrically connected to an electrode of the display element including the liquid crystal layer, and the second transistor is electrically connected to an electrode of the display element including the light-emitting layer. The electrode of the display element including the liquid crystal layer and the electrode of the display element including the light-emitting layer each include a reflective film and a conductive film. The reflective film of the display element including the liquid crystal layer has a region containing a metal contained in the reflective film of the display element including the light-emitting layer.

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: To provide a novel light-emitting device, a light-emitting device that emits light of a plurality of colors includes a first light-emitting element and a second light-emitting element. The first light-emitting element includes a first lower electrode, a first light-emitting layer over the first lower electrode, a second light-emitting layer over the first light-emitting layer, and an upper electrode over the second light-emitting layer. The second light-emitting element includes a second lower electrode, the first light-emitting layer over the second lower electrode, the second light-emitting layer over the first light-emitting layer, and the upper electrode over the second light-emitting layer. An emission spectrum of the first light-emitting layer peaks at a longer wavelength than an emission spectrum of the second light-emitting layer.