Display device
A display device including a substrate, a buffer layer, an amorphous silicon layer, a first light blocking layer, a driving transistor, an upper capacitor electrode, a first switching transistor, a lower electrode, a light emitting layer, and an upper electrode. The driving transistor is disposed on a buffer layer under which a first light blocking layer is located and includes a first active layer including polysilicon and a first gate electrode disposed on the first active layer. An upper capacitor electrode is disposed on the first gate electrode and includes a metal oxide semiconductor. The upper capacitor electrode constitutes a capacitor together with the first gate electrode.
1 . A display device comprising:
a substrate including a first polyimide layer, a first barrier layer, a second polyimide layer, and a second barrier layer, which are sequentially stacked;
a buffer layer on the substrate;
an amorphous silicon layer between the first barrier layer and the second polyimide layer;
a first light blocking layer between the second polyimide layer and the second barrier layer;
a driving transistor on the buffer layer under which the first light blocking layer is located, and including a first active layer including polysilicon and a first gate electrode disposed on the first active layer;
an upper capacitor electrode on the first gate electrode, the upper capacitor electrode being a metal oxide semiconductor and constituting a capacitor together with the first gate electrode;
a first switching transistor including a second active layer including a metal oxide semiconductor and spaced apart from the first active layer in a thickness direction and in a first direction intersecting the thickness direction, the first switching transistor further including a second gate electrode on the second active layer;
a lower electrode on the driving transistor and the first switching transistor;
a light emitting layer on the lower electrode;
an upper electrode on the light emitting layer;
a connection electrode directly connected to the lower electrode;
a second light blocking layer between the second polyimide layer and the second barrier layer and spaced apart from the first light blocking layer;
a second switching transistor including a third active layer on the second light blocking layer and a third gate electrode on the third active layer; and
a lower gate electrode under the second active layer and overlapping the second gate electrode, the lower gate electrode and the first gate electrode being coplanar and on a first same layer and including a first same material,
wherein the connection electrode directly connects a drain electrode of the second switching transistor to the lower electrode; and
wherein the upper capacitor electrode and the second active layer are coplanar and located on a second same layer, and include a second same material.
2 . The display device of claim 1 , wherein the upper capacitor electrode includes an opening that overlaps at least a part of the first gate electrode.
3 . The display device of claim 2 , further comprising:
an interlayer insulating layer on the upper capacitor electrode;
a first power supply electrode on the interlayer insulating layer; and
a second power supply electrode spaced apart from the first power supply electrode.
4 . The display device of claim 3 , wherein:
the first power supply electrode is connected to the first gate electrode through a first contact hole in a first portion of the interlayer insulating layer and passing through the opening of the upper capacitor electrode; and
the second power supply electrode is connected to the upper capacitor electrode through a second contact hole in a second portion of the interlayer insulating layer.
5 . The display device of claim 1 , wherein the substrate includes:
a first display area;
a second display area spaced apart from the first display area; and
a third display area surrounding the first and second display areas.
6 . The display device of claim 5 , further comprising a lower structure on a bottom surface of the substrate,
wherein the lower structure has first and second openings formed at portions overlapping the first and second display areas, respectively.
7 . The display device of claim 6 , wherein the first and second openings expose the bottom surface of the substrate overlapping the first and second display areas, respectively.
8 . The display device of claim 6 , wherein the lower structure includes an impact absorption layer, a heat dissipation plate, and an adhesive layer.
9 . The display device of claim 6 , further comprising:
a first functional module in the first opening of the lower structure; and
a second functional module disposed in the second opening of the lower structure.
10 . The display device of claim 9 , wherein the first functional module includes at least one of a camera module, a face recognition sensor module, a pupil recognition sensor module, an acceleration sensor module, a geomagnetic sensor module, a proximity sensor module, an infrared sensor module, or an illuminance sensor module.
11 . The display device of claim 9 , wherein the second functional module includes a fingerprint recognition sensor module.
12 . The display device of claim 1 , further comprising:
a planarization layer on the first and second switching transistors and the driving transistor;
a source electrode of the driving transistor directly connected to a bottom surface of the planarization layer;
a drain electrode of the driving transistor directly connected to the bottom surface of the planarization layer; and
the first gate electrode of the driving transistor that is not directly connected to the planarization layer.
13 . The display device of claim 12 , further comprising:
an interlayer insulating layer on the upper capacitor electrode,
wherein the interlayer insulating layer is between the source electrode of the driving transistor and the first gate electrode of the driving transistor and between the drain electrode of the driving transistor and the first gate electrode of the driving transistor to provide an electrical barrier between the drain electrode of the driving transistor and the first gate electrode of the driving transistor.
14 . The display device of claim 1 , wherein the third active layer and the first active layer are located on a same layer and include a same material.
15 . The display device of claim 1 , wherein the third gate electrode and the first gate electrode are located on a same layer and include a same material.
16 . The display device of claim 1 , further comprising a thin film encapsulation structure on the upper electrode,
wherein the thin film encapsulation structure includes:
a first inorganic thin film encapsulation layer;
an organic thin film encapsulation layer on the first inorganic thin film encapsulation layer; and
a second inorganic thin film encapsulation layer on the organic thin film encapsulation layer.