Light-emitting device including light-emitting layer in which thermally activated delayed fluorescence bodies and quantum dots are dispersed and manufacturing apparatus of light-emitting device
To provide a light-emitting device that can obtain fluorescence having a narrow spectrum more efficiently, a light-emitting device includes: a light-emitting layer in which thermally activated delayed fluorescence bodies and quantum dots are dispersed; a first electrode in a lower layer than the light-emitting layer; and a second electrode in an upper layer than the light-emitting layer, wherein a light emission spectrum of the thermally activated delayed fluorescence bodies and an absorption spectrum of the quantum dots at least partially overlap each other.
1. A light-emitting device comprising:
a light-emitting layer in which thermally activated delayed fluorescence bodies and quantum dots are dispersed in a host;
a first electrode in a layer below the light-emitting layer; and
a second electrode in a layer above the light-emitting layer,
wherein a light emission spectrum of the thermally activated delayed fluorescence bodies and an absorption spectrum of the quantum dots at least partially overlap each other,
the host includes: a dispersing material; and a compound having a function of injecting and transporting holes and electrons, and
an intermolecular distance between the thermally activated delayed fluorescence bodies and the quantum dots is smaller than a distance over which energy is transferred from the thermally activated delayed fluorescence bodies to the quantum dots.
2. The light-emitting device according to claim 1 ,
wherein an exciton generated in the thermally activated delayed fluorescence bodies transitions, through a resonance phenomenon of a dipole vibration, to a conduction band level of the quantum dots, and the quantum dots emit light.
3. The light-emitting device according to claim 1 ,
wherein a peak wavelength of the light emission spectrum of the thermally activated delayed fluorescence bodies is shorter than a peak wavelength of a light emission spectrum of the quantum dots.
4. The light-emitting device according to claim 1 ,
wherein a peak wavelength of the light emission spectrum of the thermally activated delayed fluorescence bodies is included in the absorption spectrum of the quantum dots.
5. The light-emitting device according to claim 1 ,
wherein a peak wavelength of the absorption spectrum of the quantum dots is included in the light emission spectrum of the thermally activated delayed fluorescence bodies.
6. The light-emitting device according to claim 1 ,
wherein a concentration of the thermally activated delayed fluorescence bodies in the light-emitting layer is from 10 mass % to 30 mass %.
7. The light-emitting device according to claim 1 ,
wherein a concentration of the quantum dots in the light-emitting layer is from 0.1 mass % to 1 mass %.
8. The light-emitting device according to claim 1 ,
wherein an edge cover is provided, the edge cover including a plurality of openings, the edge cover being configured to define the light-emitting layer into a plurality of pixel areas, and for each of the plurality of openings, the light-emitting layer covers the plurality of openings, and an upper end of the edge cover surrounds the light-emitting layer.
9. The light-emitting device according to claim 1 ,
wherein the light-emitting layer includes a photosensitive material, and the thermally activated delayed fluorescence bodies and the quantum dots are dispersed in the photosensitive material.
10. A manufacturing apparatus of a light-emitting device, the manufacturing apparatus comprising
a film formation apparatus configured to form:
a light-emitting layer in which thermally activated delayed fluorescence bodies and quantum dots are dispersed in a host, an absorption spectrum of the quantum dots at least partially overlapping with a light emission spectrum of the thermally activated delayed fluorescence bodies;
a first electrode in a layer below the light-emitting layer; and
a second electrode in a layer above the light-emitting layer,
wherein the host includes: a dispersing material; and a compound having a function of injecting and transporting holes and electrons, and
an intermolecular distance between the thermally activated delayed fluorescence bodies and the quantum dots is smaller than a distance over which energy is transferred from the thermally activated delayed fluorescence bodies to the quantum dots.