Display device, display module, electronic device, and television device
A display device having a long lifetime is provided. A large-sized display device is provided. A display device includes a first light-emitting device and a second light-emitting device. The first light-emitting device includes a hole-injection layer, a first light-emitting layer, and an electron-transport layer. The second light-emitting device includes a second light-emitting layer. The hole-injection layer contains a first compound and a second compound. The first light-emitting layer contains a third compound that emits light of a first color. The second light-emitting layer contains a fourth compound that emits light of a second color. The electron-transport layer contains a fifth compound. The first compound has a property of accepting electrons from the second compound. The second compound has a HOMO level higher than or equal to −5.7 eV and lower than or equal to −5.4 eV. The fifth compound has a HOMO level higher than or equal to −6.0 eV and an electron mobility higher than or equal to 1×10{circumflex over ( )}−7 cm{circumflex over ( )}2/Vs and lower than or equal to 5×10{circumflex over ( )}−5 cm{circumflex over ( )}2/Vs when the square root of electric field strength [V/cm] is 600.
1 . A display device comprising:
a first light-emitting device; and
a second light-emitting device,
wherein the first light-emitting device comprises a first electrode and a common electrode,
wherein the second light-emitting device comprises a second electrode and the common electrode,
wherein the first light-emitting device comprises a hole-injection layer, a first light-emitting layer, and an electron-transport layer in this order from a side of the first electrode,
wherein the second light-emitting device comprises a second light-emitting layer between the second electrode and the common electrode,
wherein the hole-injection layer is in contact with the first electrode,
wherein the hole-injection layer comprises a first compound and a second compound,
wherein the first light-emitting layer comprises a third compound that emits light of a first color,
wherein the second light-emitting layer comprises a fourth compound that emits light of a second color,
wherein the electron-transport layer comprises a fifth compound,
wherein the first compound comprises at least one of a cyano group and a fluoro group,
wherein a HOMO level of the second compound is higher than or equal to −5.7 eV and lower than or equal to −5.4 eV, and
wherein a HOMO level of the fifth compound is higher than or equal to −6.0 eV.
2 . The display device according to claim 1 ,
wherein the fifth compound is a triazine derivative, a phenanthroline derivative, or a compound comprising an anthracene skeleton.
3 . The display device according to claim 1 ,
wherein the first color is blue.
4 . The display device according to claim 1 ,
wherein each of the third compound and the fourth compound is a fluorescent substance.
5 . The display device according to claim 1 ,
wherein the second light-emitting device comprises a layer shared with the first light-emitting device between the second electrode and the common electrode.
6 . The display device according to claim 1 ,
wherein the second compound comprises at least one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton.
7 . The display device according to claim 1 ,
wherein the electron-transport layer further comprises an organic complex comprising an alkali metal or an alkaline earth metal.
8 . A display device comprising:
a first light-emitting device; and
a second light-emitting device,
wherein the first light-emitting device comprises a first electrode and a common electrode,
wherein the second light-emitting device comprises a second electrode and the common electrode,
wherein the first light-emitting device comprises a hole-injection layer, a first hole-transport layer, a first light-emitting layer, and an electron-transport layer in this order from a side of the first electrode,
wherein the second light-emitting device comprises a second light-emitting layer between the second electrode and the common electrode,
wherein the hole-injection layer is in contact with the first electrode,
wherein the hole-injection layer comprises a first compound and a second compound,
wherein the first light-emitting layer comprises a third compound that emits light of a first color,
wherein the second light-emitting layer comprises a fourth compound that emits light of a second color,
wherein the electron-transport layer comprises a fifth compound,
wherein the first hole-transport layer comprises a sixth compound,
wherein the first compound comprises at least one of a cyano group and a fluoro group,
wherein a HOMO level of the second compound is higher than or equal to −5.7 eV and lower than or equal to −5.4 eV,
wherein a HOMO level of the fifth compound is higher than or equal to −6.0 eV,
wherein a HOMO level of the sixth compound is lower than or equal to the HOMO level of the second compound, and
wherein a difference between the HOMO level of the sixth compound and the HOMO level of the second compound is 0.2 eV or less.
9 . The display device according to claim 8 ,
wherein the fifth compound is a triazine derivative, a phenanthroline derivative, or a compound comprising an anthracene skeleton.
10 . The display device according to claim 8 ,
wherein the first color is blue.
11 . The display device according to claim 8 ,
wherein each of the third compound and the fourth compound is a fluorescent substance.
12 . The display device according to claim 8 ,
wherein the second light-emitting device comprises a layer shared with the first light-emitting device between the second electrode and the common electrode.
13 . The display device according to claim 8 ,
wherein the second compound comprises at least one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton.
14 . The display device according to claim 8 ,
wherein the electron-transport layer further comprises an organic complex comprising an alkali metal or an alkaline earth metal.
15 . The display device according to claim 8 ,
wherein the first light-emitting device further comprises a second hole-transport layer,
wherein the second hole-transport layer comprises a seventh compound, and
wherein a HOMO level of the seventh compound is lower than the HOMO level of the sixth compound.
16 . A display device comprising:
a first light-emitting device;
a second light-emitting device; and
a third light-emitting device,
wherein the first light-emitting device comprises a first electrode and a common electrode,
wherein the second light-emitting device comprises a second electrode and the common electrode,
wherein the third light-emitting device comprises a third electrode and the common electrode,
wherein the first light-emitting device comprises a hole-injection layer, a first light-emitting layer, and an electron-transport layer in this order from a side of the first electrode,
wherein the second light-emitting device comprises a second light-emitting layer between the second electrode and the common electrode,
wherein the third light-emitting device comprises a third light-emitting layer between the third electrode and the common electrode,
wherein the hole-injection layer is in contact with the first electrode,
wherein the hole-injection layer comprises a first compound and a second compound,
wherein the electron-transport layer comprises a third compound,
wherein the first compound comprises at least one of a cyano group and a fluoro group,
wherein a HOMO level of the second compound is higher than or equal to −5.7 eV and lower than or equal to −5.4 eV,
wherein a maximum peak wavelength of an emission spectrum of the first light-emitting device is shorter than a maximum peak wavelength of an emission spectrum of the second light-emitting device,
wherein the maximum peak wavelength of the emission spectrum of the second light-emitting device is shorter than a maximum peak wavelength of an emission spectrum of the third light-emitting device, and
wherein in a top view, an area of a light-emitting region of the first light-emitting device is larger than or equal to an area of a light-emitting region of the third light-emitting device and smaller than or equal to an area of a light-emitting region of the second light-emitting device.
17 . The display device according to claim 16 ,
wherein the third compound is a triazine derivative, a phenanthroline derivative, or a compound comprising an anthracene skeleton.
18 . The display device according to claim 16 ,
wherein the second compound comprises at least one of a carbazole skeleton, a dibenzofuran skeleton, a dibenzothiophene skeleton, and an anthracene skeleton.
19 . The display device according to claim 16 ,
wherein the electron-transport layer further comprises an organic complex comprising an alkali metal or an alkaline earth metal.