Light-emitting device and electronic apparatus including the same
Embodiments provide a light-emitting device and an electronic apparatus including the same. The light-emitting device includes a first electrode, a second electrode facing the first electrode, m light-emitting units stacked between the first electrode and the second electrode, and m−1 charge generation layers between adjacent ones of the light-emitting. Each light-emitting unit includes an emission layer; the m light-emitting units include a first light-emitting unit, a second light-emitting unit, a third light-emitting unit, a fourth light-emitting unit, and a fifth light-emitting unit; the m−1 charge generation layers include a first charge generation layer, a second charge generation layer, a third charge generation layer, and a fourth charge generation layer; the first light-emitting unit and the second light-emitting unit each emit green light; and the third light-emitting unit, the fourth light-emitting unit, and the fifth light-emitting unit each emit blue light.
1 . A light-emitting device comprising:
a first electrode;
a second electrode facing the first electrode;
m light-emitting units stacked between the first electrode and the second electrode; and
m−1 charge generation layers between adjacent ones of the m light-emitting units, wherein
m is an integer of 5 or more,
each light-emitting unit comprises an emission layer,
the m light-emitting units comprise a first light-emitting unit, a second light-emitting unit, a third light-emitting unit, a fourth light-emitting unit, and a fifth light-emitting unit,
the m−1 charge generation layers comprise a first charge generation layer, a second charge generation layer, a third charge generation layer, and a fourth charge generation layer,
the first light-emitting unit and the second light-emitting unit each emit green light, the third light-emitting unit, the fourth light-emitting unit, and the fifth light-emitting unit each emit blue light, and wherein the first light-emitting unit and the second light-emitting unit are not adjacent to each other.
2 . The light-emitting device of claim 1 , wherein m is 5.
3 . The light-emitting device of claim 1 , wherein the emission layers of the first light-emitting unit and the second light-emitting unit each emit light having a maximum emission wavelength in a range of about 500 nm to about 600 nm.
4 . The light-emitting device of claim 1 , wherein the emission layers of the third light-emitting unit, the fourth light-emitting unit, and the fifth light-emitting unit each emit light having a maximum emission wavelength in a range of about 400 nm to about 500 nm.
5 . The light-emitting device of claim 1 , wherein
the first light-emitting unit is a light-emitting unit that is most toward the first electrode; or
the second light-emitting unit is a light-emitting unit that is most toward the second electrode.
6 . The light-emitting device of claim 1 , wherein the first light-emitting unit or the second light-emitting unit is between the third light-emitting unit and the fifth light-emitting unit.
7 . The light-emitting device of claim 2 , wherein
the first charge generation layer is between the third light-emitting unit and the fourth light-emitting unit,
the second charge generation layer is between the fourth light-emitting unit and the first light-emitting unit,
the third charge generation layer is between the first light-emitting unit and the fifth light-emitting unit, and
the fourth charge generation layer is between the fifth light-emitting unit and the second light-emitting unit.
8 . The light-emitting device of claim 2 , wherein
the first charge generation layer is between the first light-emitting unit and the third light-emitting unit,
the second charge generation layer is between the third light-emitting unit and the fourth light-emitting unit,
the third charge generation layer is between the fourth light-emitting unit and the second light-emitting unit, and
the fourth charge generation layer is between the second light-emitting unit and the fifth light-emitting unit.
9 . The light-emitting device of claim 2 , wherein
the first charge generation layer is between the first light-emitting unit and the third light-emitting unit,
the second charge generation layer is between the third light-emitting unit and the second light-emitting unit,
the third charge generation layer is between the second light-emitting unit and the fourth light-emitting unit, and
the fourth charge generation layer is between the fourth light-emitting unit and the fifth light-emitting unit.
10 . The light-emitting device of claim 1 , wherein Formula 1 is satisfied:
3800 Å≤ D 1 ≤4500 Å (1)
wherein in Formula 1,
D 1 represents a distance between an interface between the first electrode and a light-emitting unit that is most toward the first electrode, and an interface between the second electrode and a light-emitting unit that is most toward the second electrode.
11 . The light-emitting device of claim 1 , wherein Formula 2-1 is satisfied:
3≤ D 1 /(2*λ 1 )≤4 (2-1)
wherein in Formula 2-1,
D 1 represents a distance between an interface between the first electrode and a light-emitting unit that is most toward the first electrode, and an interface between the second electrode and a light-emitting unit that is most toward the second electrode, and
λ 1 represents a maximum emission wavelength of the first light-emitting unit.
12 . The light-emitting device of claim 1 , wherein Formula 2-2 is satisfied:
4≤ D 1 /(2*λ 3 )≤5 (2-2)
wherein in Formula 2-2,
D 1 represents a distance between an interface between the first electrode and a light-emitting unit that is most toward the first electrode, and an interface between the second electrode and a light-emitting unit that is most toward the second electrode, and
λ 3 represents a maximum emission wavelength of the third light-emitting unit.
13 . The light-emitting device of claim 1 , wherein at least one of the m−1 charge generation layers comprises an n-type charge generation layer and a p-type charge generation layer.
14 . The light-emitting device of claim 1 , wherein
at least one emission layer comprises a first host and a second host, and
the first host and the second host are different from each other.
15 . The light-emitting device of claim 1 , wherein at least one emission layer comprises a first emission layer and a second emission layer.
16 . The light-emitting device of claim 1 , further comprising a capping layer arranged outside the second electrode.
17 . An electronic apparatus comprising the light-emitting device of claim 1 .
18 . The electronic apparatus of claim 17 , further comprising a thin-film transistor, wherein
the thin-film transistor comprises a source electrode and a drain electrode, and
the first electrode of the light-emitting device is electrically connected to at least one of the source electrode and the drain electrode.
19 . The electronic apparatus of claim 17 , further comprising a color filter, a color conversion layer, a quantum dot color conversion layer, a touch screen layer, a polarizing layer, or a combination thereof.