Light emitting device, manufacturing method of the light emitting device, and display device comprising the same
A light-emitting device includes a first electrode; a second electrode that overlaps the first electrode in a plan view; an emission layer disposed between the first electrode and the second electrode; a hole transport region disposed between the first electrode and the emission layer; and an electron transport region disposed between the emission layer and the second electrode, and at least one of the hole transport region or the electron transport region includes a recess portion.
1 . A light-emitting device comprising:
a first electrode;
a second electrode that overlaps the first electrode in a plan view;
an emission layer disposed between the first electrode and the second electrode;
a hole transport region disposed between the first electrode and the emission layer, the hole transport region having a planar surface facing the emission layer; and
an electron transport region disposed between the emission layer and the second electrode, wherein
the hole transport region includes
a plurality of first recess portions randomly disposed across an entirety of the planar surface facing the emission layer, each first recess portion is recessed into the planar surface, each first recess portion is a depression formed by pressing the planar surface of the hole transport region by external pressure.
2 . The light-emitting device of claim 1 , wherein the first recess portions have different sizes and shapes.
3 . The light-emitting device of claim 1 , wherein
the electron transport region includes a second recess portion, and
the second recess portion is disposed on a side of the hole transport region facing the second electrode.
4 . The light-emitting device of claim 3 , wherein
the electron transport region includes second recess portions, and
the second recess portions are randomly disposed.
5 . The light-emitting device of claim 4 , wherein the second recess portions have different sizes and shapes.
6 . A manufacturing method of a light-emitting device, comprising:
forming a hole transport region on a first electrode; and
forming an emission layer, an electron transport region, and a second electrode on the hole transport region, sequentially,
wherein the forming of the hole transport region includes forming a planar surface facing the emission layer on the hole transport region and forming a plurality of first recess portions randomly disposed across an entirety of the planar surface facing the emission layer, each first recess portion recessed into the planar surface by a pressurized film.
7 . The manufacturing method of claim 6 , wherein the pressurized film includes:
a first layer including carbon black; and
a second layer including nanoparticles and disposed on the first layer.
8 . The manufacturing method of claim 7 , wherein the forming of the hole transport region includes:
applying light to the pressurized film after bringing the second layer into contact with the hole transport region.
9 . The manufacturing method of claim 8 , wherein the carbon black converts the light into thermal energy that allows the nanoparticles to press the hole transport region.
10 . The manufacturing method of claim 6 , wherein the hole transport region is formed by removing the pressurized film.
11 . A display device comprising the light-emitting device according to claim 1 .
12 . The light-emitting device of claim 1 , wherein a distance between each of the plurality of first recess portions varies irregularly across the entirety of the planar surface of the hole transport region facing the emission layer.
13 . The light-emitting device of claim 1 , wherein both the hole transport region and the electron transport region include the recess portion.