Light-emitting element, light-emitting device provided with light-emitting element, and light-emitting element production method
View Patent ↗Organic EL elements are configured so that at least a hole injection layer and a light-emitting layer are laminated between a first electrode and a second electrode, and a bank defines an area in which the light-emitting layer is to be formed. An inner portion of the hole injection layer is depressed to define a recess. An upper peripheral edge of the recess is covered with a part of the bank.
1. A light-emitter, comprising:
a first electrode;
a laminate disposed on the first electrode that includes a charge injection layer, a charge transport layer, and a light-emitting layer;
a second electrode disposed on the laminate; and
a bank that defines an area in which the light-emitting layer is disposed, wherein
a portion of the charge injection layer that is within the area defined by the bank is depressed to define a recess, the recess being continuous across the area defined by the bank,
an upper peripheral edge of the recess is covered with a part of the bank, the part of the bank being in the recess and having a bottom surface below an upper surface of an outer portion of the charge injection layer which is not depressed to define the recess, and
a lower surface of the charge transport layer faces a portion of the recess not covered with the part of the bank.
2. The light-emitter of claim 1 , wherein the charge transport layer is in contact with the part of the bank covering the upper peripheral edge of the recess.
3. The light-emitter of claim 1 , wherein the charge transport layer is surrounded by (i) a portion of the recess in the area defined by the bank and (ii) the part of the bank covering the upper peripheral edge of the recess.
4. The light-emitter of claim 1 , wherein the charge injection layer is made from a material that is eroded when exposed to a liquid used for forming the bank.
5. The light-emitter of claim 4 , wherein the liquid is water or a TMAH solution.
6. The light-emitter of claim 1 , wherein the charge injection layer is made from one of a metal oxide, a metal nitride, and a metal oxynitride.
7. The light-emitter of claim 1 , wherein the part of the bank reaches a bottom of the recess, and a side surface of the bank slopes upward from the bottom of the recess to a top of the bank.
8. The light-emitter of claim 1 , wherein the part of the bank is out of contact with a bottom of the recess.
9. The light-emitter of claim 1 , wherein the bank includes an insulating material.
10. The light-emitter of claim 1 , wherein the light-emitting layer comprises an organic EL layer.
11. The light-emitter of claim 1 , wherein the charge injection layer extends laterally along a bottom surface of the bank.
12. The light-emitter of claim 1 , wherein the upper peripheral edge of the recess is convex.
13. A light-emitting device comprising a plurality of light-emitters that are each the light-emitter of claim 1 .
14. The light-emitter of claim 1 , wherein the part of the bank directly contacts an inner side surface of the recess.
15. The light-emitter of claim 1 , wherein the upper peripheral edge of the recess defines a right angle.
16. The light-emitter of claim 1 , wherein an inclination angle of the part of the bank which covers the recess is different than an inclination angle of a top part of the bank.
17. The light-emitter of claim 16 , wherein the inclination angle of the part of the bank which covers the recess is less than the inclination angle of the top part of the bank.
18. The light-emitter of claim 1 , wherein a bottom surface of the recess is longer than and parallel with a top surface of the first electrode.
19. The light-emitter of claim 1 , wherein a shortest distance between the upper peripheral edge of the recess and the hole transport layer is 2 nm to 5 nm.