Abstract: To provide a flexible, highly reliable power storage device or light-emitting device. The device includes a battery unit or a light-emitting unit and a member with rubber elasticity. The battery unit includes a secondary battery. The light-emitting unit includes a light-emitting element. The member with rubber elasticity is provided with a first projection and a second projection. The first projection and the second projection are arranged on a first surface of the battery unit or the light-emitting unit. The first projection and the second projection come in contact with each other when the power storage device is bent such that the first surface of the battery unit faces inward.

Abstract: A highly reliable display device. A first flexible substrate and a second flexible substrate overlap each other with a display element positioned therebetween. Side surfaces of at least one of the first substrate and the second substrate which overlap each other are covered with a high molecular material having a light-transmitting property. The high molecular material is more flexible than the first substrate and the second substrate.

Abstract: An object of one embodiment of the present invention is to provide a multicolor light-emitting element that utilizes fluorescence and phosphorescence and is advantageous for practical application. The light-emitting element has a stacked-layer structure of a first light-emitting layer containing a host material and a fluorescent substance, a separation layer containing a substance having a hole-transport property and a substance having an electron-transport property, and a second light-emitting layer containing two kinds of organic compounds that form an exciplex and a substance that can convert triplet excitation energy into luminescence. Note that a light-emitting element in which light emitted from the first light-emitting layer has an emission spectrum peak on the shorter wavelength side than an emission spectrum peak of the second light-emitting layer is more effective.

Abstract: A light-emitting element includes a stack of a first light-emitting layer emitting fluorescent light and a second light-emitting layer emitting phosphorescent light between a pair of electrodes. The second light-emitting layer includes a first layer in which an exciplex is formed, a second layer in which an exciplex is formed, and a third layer in which an exciplex is formed. The second layer is located over the first layer, and the third layer is located over the second layer. An emission peak wavelength of the second layer is longer than an emission peak wavelength of the first layer and an emission peak wavelength of the third layer.

Abstract: An object of one embodiment of the present invention is to provide a multicolor light-emitting element that utilizes fluorescence and phosphorescence and is advantageous for practical application. The light-emitting element has a stacked-layer structure of a first light-emitting layer containing a host material and a fluorescent substance, a separation layer containing a substance having a hole-transport property and a substance having an electron-transport property, and a second light-emitting layer containing two kinds of organic compounds that form an exciplex and a substance that can convert triplet excitation energy into luminescence. Note that a light-emitting element in which light emitted from the first light-emitting layer has an emission spectrum peak on the shorter wavelength side than an emission spectrum peak of the second light-emitting layer is more effective.

Abstract: A highly reliable display device. A first flexible substrate and a second flexible substrate overlap each other with a display element positioned therebetween. Side surfaces of at least one of the first substrate and the second substrate which overlap each other are covered with a high molecular material having a light-transmitting property. The high molecular material is more flexible than the first substrate and the second substrate.

Abstract: An object of one embodiment of the present invention is to provide a multicolor light-emitting element that utilizes fluorescence and phosphorescence and is advantageous for practical application. The light-emitting element has a stacked-layer structure of a first light-emitting layer containing a host material and a fluorescent substance, a separation layer containing a substance having a hole-transport property and a substance having an electron-transport property, and a second light-emitting layer containing two kinds of organic compounds that form an exciplex and a substance that can convert triplet excitation energy into luminescence. Note that a light-emitting element in which light emitted from the first light-emitting layer has an emission spectrum peak on the shorter wavelength side than an emission spectrum peak of the second light-emitting layer is more effective.

Abstract: An object of one embodiment of the present invention is to provide a multicolor light-emitting element that utilizes fluorescence and phosphorescence and is advantageous for practical application. The light-emitting element has a stacked-layer structure of a first light-emitting layer containing a host material and a fluorescent substance, a separation layer containing a substance having a hole-transport property and a substance having an electron-transport property, and a second light-emitting layer containing two kinds of organic compounds that form an exciplex and a substance that can convert triplet excitation energy into luminescence. Note that a light-emitting element in which light emitted from the first light-emitting layer has an emission spectrum peak on the shorter wavelength side than an emission spectrum peak of the second light-emitting layer is more effective.

Abstract: A light-emitting element includes a stack of a first light-emitting layer emitting fluorescent light and a second light-emitting layer emitting phosphorescent light between a pair of electrodes. The second light-emitting layer includes a first layer in which an exciplex is formed, a second layer in which an exciplex is formed, and a third layer in which an exciplex is formed. The second layer is located over the first layer, and the third layer is located over the second layer. An emission peak wavelength of the second layer is longer than an emission peak wavelength of the first layer and an emission peak wavelength of the third layer.

Abstract: A highly reliable display device. A first flexible substrate and a second flexible substrate overlap each other with a display element positioned therebetween. Side surfaces of at least one of the first substrate and the second substrate which overlap each other are covered with a high molecular material having a light-transmitting property. The high molecular material is more flexible than the first substrate and the second substrate.

Abstract: A light-emitting element includes a stack of a first light-emitting layer emitting fluorescent light and a second light-emitting layer emitting phosphorescent light between a pair of electrodes. The second light-emitting layer includes a first layer in which an exciplex is formed, a second layer in which an exciplex is formed, and a third layer in which an exciplex is formed. The second layer is located over the first layer, and the third layer is located over the second layer. An emission peak wavelength of the second layer is longer than an emission peak wavelength of the first layer and an emission peak wavelength of the third layer.

Abstract: A highly reliable display device. A first flexible substrate and a second flexible substrate overlap each other with a display element positioned therebetween. Side surfaces of at least one of the first substrate and the second substrate which overlap each other are covered with a high molecular material having a light-transmitting property. The high molecular material is more flexible than the first substrate and the second substrate.

Abstract: A solid-state light-emitting element includes a structure body having a property of transmitting visible light and an uneven structure on each of the top side and the bottom side thereof; a high refractive index material layer provided on one surface of the structure body; and a light-emitting body with a refractive index of greater than or equal to 1.6 provided over the high refractive index material layer. One surface of the high refractive index material layer is flatter than the other surface thereof which is in contact with the structure body. The refractive index of the high refractive index material layer is greater than or equal to 1.6. The refractive index of the structure body is greater than 1.0 and less than that of the high refractive index material layer.

Abstract: A highly reliable display device. A first flexible substrate and a second flexible substrate overlap each other with an element positioned therebetween. A periphery of the overlapped first and second substrates is covered with a high molecular material having a light-transmitting property. The high molecular material is more flexible than the first substrate and the second substrate. As the element, for example, an EL element can be used.

Abstract: The semiconductor device includes a first insulator over a substrate, a first oxide semiconductor over the first insulator, a second oxide semiconductor over the first oxide semiconductor, a first conductor and a second conductor in contact with the second oxide semiconductor, a third oxide semiconductor on the second oxide semiconductor and the first and second conductors, a second insulator over the third oxide semiconductor, and a third conductor over the second insulator. At least one of the first oxide semiconductor, the second oxide semiconductor, and the third oxide semiconductor has a crystallinity peak that corresponds to a (hkl) plane (h=0, k=0, l is a natural number) observed by X-ray diffraction using a Cu K-alpha radiation as a radiation source. The peak appears at a diffraction angle 2 theta greater than or equal to 31.3 degrees and less than 33.5 degrees.

Abstract: A bendable display device, lighting device, or electronic device which is unlikely to be broken when handled. The display device, lighting device, or electronic device includes two flexible substrates, and at least one of the two flexible substrates contains a plurality of glass fibers extending in one direction. Accordingly, the display device, lighting device, or electronic device has low flexibility in the one direction and is unlikely to be broken when handled.

Abstract: An oxide with high crystallinity is provided. An oxide having a crystal structure with few defects is provided. An oxide with a low density of defect states is provided. An oxide with a low impurity concentration is provided. A film forming apparatus capable of forming a film of the above-described oxide can be provided. The film forming apparatus includes a target holder, a substrate holder, a first power source, and a second power source. The target holder is electrically connected to the first power source, the substrate holder is electrically connected to the second power source, and the second power source is configured to apply a potential that is higher than a ground potential.

Abstract: A solid-state light-emitting element includes a structure body having a property of transmitting visible light and an uneven structure on each of the top side and the bottom side thereof; a high refractive index material layer provided on one surface of the structure body; and a light-emitting body with a refractive index of greater than or equal to 1.6 provided over the high refractive index material layer. One surface of the high refractive index material layer is flatter than the other surface thereof which is in contact with the structure body. The refractive index of the high refractive index material layer is greater than or equal to 1.6. The refractive index of the structure body is greater than 1.0 and less than that of the high refractive index material layer.

Abstract: A display device, an electronic device, or a lighting device that is unlikely to be broken is provided. A flexible first substrate and a flexible second substrate overlap with each other with a display element provided therebetween. A flexible third substrate is bonded on the outer surface of the first substrate, and a flexible fourth substrate is bonded on the outer surface of the second substrate. The third substrate is formed using a material softer than the first substrate, and the fourth substrate is formed using a material softer than the second substrate.

Abstract: A light-emitting element includes a stack of a first light-emitting layer emitting fluorescent light and a second light-emitting layer emitting phosphorescent light between a pair of electrodes. The second light-emitting layer includes a first layer in which an exciplex is formed, a second layer in which an exciplex is formed, and a third layer in which an exciplex is formed. The second layer is located over the first layer, and the third layer is located over the second layer. An emission peak wavelength of the second layer is longer than an emission peak wavelength of the first layer and an emission peak wavelength of the third layer.