Display device and flexible display device including a storage capacitor
According to an embodiment of the disclosure, a display device includes a pixel circuit layer including a base layer and a pixel circuit disposed on the base layer, and a light emitting element disposed on the base layer and electrically connected to the pixel circuit. The pixel circuit includes a transistor and a storage capacitor including a first capacitor electrode and a second capacitor electrode. The base layer includes a concave portion. At least a portion of each of the first capacitor electrode and the second capacitor electrode is disposed in the concave portion.
1 . A display device comprising:
a pixel circuit layer including a base layer and a pixel circuit disposed on the base layer; and
a light emitting element disposed on the base layer and electrically connected to the pixel circuit, wherein
the pixel circuit includes:
a transistor, and
a storage capacitor including a first capacitor electrode and a second capacitor electrode, wherein
the base layer includes a concave portion, and at least a portion of each of the first capacitor electrode and the second capacitor electrode is disposed in the concave portion,
facing surfaces facing each other, an insulating layer disposed between the facing surfaces,
the facing surfaces includes first facing surfaces and second facing surfaces,
the first facing surfaces extend along a first surface,
the second facing surfaces extend along a second surface different from the first surface, and
a normal direction of the second surface is different from a thickness direction of the base layer.
2 . The display device according to claim 1 , wherein the concave portion has a bottom surface, and a depth of the concave portion is less than a length of the bottom surface.
3 . The display device according to claim 1 , wherein a depth of the concave portion is about 10% to about 95% of a thickness of the base layer.
4 . The display device according to claim 1 , wherein
the storage capacitor includes a well portion in the concave portion,
the pixel circuit layer includes a lower auxiliary electrode layer, an active layer, and an interlayer conductive layer for forming the pixel circuit,
the first capacitor electrode is formed as the lower auxiliary electrode layer, and the second capacitor electrode is formed as the active layer.
5 . The display device according to claim 4 , wherein
the transistor includes a driving transistor,
a first source electrode and a first drain electrode of the driving transistor are formed as the interlayer conductive layer, and
the first capacitor electrode and the second capacitor electrode of the storage capacitor and the first source electrode and the first drain electrode of the driving transistor are formed on different layers, respectively.
6 . The display device according to claim 5 , further comprising:
a sync conductive layer overlapping a first gate electrode of the driving transistor in a plan view and formed as the lower auxiliary electrode layer,
wherein the first capacitor electrode is electrically connected to the first source electrode and the sync conductive layer, and is electrically connected to an anode electrode of the light emitting element through a bridge pattern layer formed as the interlayer conductive layer.
7 . The display device according to claim 5 , further comprising: a data line electrically connected to the pixel circuit, wherein
the transistor further includes a switching transistor electrically connected to the data line, and
a direction in which the data line extends and a direction in which the well portion extends are parallel.
8 . The display device according to claim 5 , further comprising: a data line electrically connected to the pixel circuit, wherein
the transistor further includes a switching transistor electrically connected to the data line, and
the well portion is disposed between a first gate electrode of the driving transistor and a second gate electrode of the switching transistor in a plan view.
9 . The display device according to claim 8 , wherein a direction in which the first gate electrode and the second gate electrode extend and a direction in which the well portion extends are parallel.
10 . The display device according to claim 8 , wherein
the second capacitor electrode and a second source electrode of the switching transistor are integral with each other, and
the second capacitor electrode and a second drain electrode of the switching transistor are integral with each other.
11 . The display device according to claim 5 , wherein the well portion does not overlap the interlayer conductive layer in a plan view.
12 . The display device according to claim 1 , further comprising:
a first sub-pixel, a second sub-pixel, and a third sub-pixel each including the light emitting element, wherein
the storage capacitor includes a well portion in the concave portion,
the storage capacitor includes a first storage capacitor in the first sub-pixel, a second storage capacitor in the second sub-pixel, and a third storage capacitor in the third sub-pixel, and
each of the first storage capacitor, the second storage capacitor, and the third storage capacitor includes the well portion.
13 . The display device according to claim 1 , further comprising:
a first sub-pixel, a second sub-pixel, and a third sub-pixel each including the light emitting element, wherein
the storage capacitor includes a well portion in the concave portion,
the storage capacitor includes a first storage capacitor in the first sub-pixel, a second storage capacitor in the second sub-pixel, and a third storage capacitor in the third sub-pixel,
the well portion is not formed in the first storage capacitor and the second storage capacitor,
the well portion is formed in the third storage capacitor, and
a capacitance of the third storage capacitor is greater than a capacitance of the first storage capacitor and a capacitance of the second storage capacitor.
14 . The display device according to claim 13 , wherein areas of each of the first storage capacitor, the second storage capacitor, and the third storage capacitor are substantially equal to each other in a plan view.
15 . The display device according to claim 13 , wherein structures of each of the first storage capacitor, the second storage capacitor, and the third storage capacitor are substantially same as each other in a plan view.
16 . The display device according to claim 1 , wherein
the pixel circuit layer includes a circuit-free area in which the pixel circuit is not disposed, and
the base layer is configured to transmit light so that the display device has a rear emission structure.
17 . The display device according to claim 1 , wherein
the storage capacitor includes a well portion in the concave portion, and
the well portion has a shape including a long side extending in a first direction and a short side extending in a second direction different from the first direction.
18 . The display device according to claim 1 , wherein
the storage capacitor includes a well portion in the concave portion,
the well portion includes a plurality of well portions, and
the plurality of well portions are arranged in a matrix structure in a row direction along a first direction and a column direction along a second direction different from the first direction.
19 . The display device according to claim 1 , wherein
the storage capacitor includes a well portion in the concave portion,
the well portion includes a plurality of well portions, and
the plurality of well portions are sequentially arranged along a direction.
20 . The display device according to claim 1 , wherein the light emitting element is an organic light emitting diode (OLED).
21 . The display device according to claim 1 , wherein the display device is one or more of a bendable display device, a curved display device, and a foldable display device.
22 . The display device according to claim 21 , wherein
the display device is bendable along a bending line,
the storage capacitor includes a well portion in the concave portion, and
a direction in which the bending line extends and a direction in which the well portion extends is same as each other.
23 . The display device according to claim 1 , wherein
the transistor includes:
a gate electrode formed as a first interlayer conductive layer, and
a source electrode and a drain electrode formed as a second interlayer conductive layer on the first interlayer conductive layer,
the first capacitor electrode is formed as the first interlayer conductive layer, and
the second capacitor electrode is formed as the second interlayer conductive layer.
24 . An electronic device comprising:
a pixel circuit layer including a base layer and a pixel circuit disposed on the base layer; and
a light emitting element disposed on the base layer and electrically connected to the pixel circuit, wherein
the pixel circuit includes:
a transistor, and
a storage capacitor including a first capacitor electrode and a second capacitor electrode, wherein
the base layer includes a concave portion, and at least a portion of each of the first capacitor electrode and the second capacitor electrode is disposed in the concave portion,
facing surfaces facing each other, an insulating layer disposed between the facing surfaces,
the facing surfaces includes first facing surfaces and second facing surfaces,
the first facing surfaces extend along a first surface,
the second facing surfaces extend along a second surface different from the first surface, and
a normal direction of the second surface is different from a thickness direction of the base layer.
25 . A flexible display device foldable along a bending line, the flexible display device comprising:
a base layer including a recessed portion;
a pixel circuit including a storage capacitor including capacitor electrodes disposed in the recessed portion; and
a light emitting element electrically connected to the pixel circuit,
wherein the recessed portion has a shape extending along the bending line.
26 . A display device comprising:
a pixel circuit layer including a base layer and a pixel circuit disposed on the base layer; and
a light emitting element disposed on the base layer and electrically connected to the pixel circuit, wherein
the pixel circuit includes:
a transistor, and
a storage capacitor including a first capacitor electrode and a second capacitor electrode,
the base layer includes a concave portion, and at least a portion of each of the first capacitor electrode and the second capacitor electrode is disposed in the concave portion, wherein
a depth of the concave portion is about 10% to about 95% of a thickness of the base layer.
27 . The display device according to claim 26 , wherein
the storage capacitor includes a well portion in the concave portion,
the pixel circuit layer includes a lower auxiliary electrode layer, an active layer, and an interlayer conductive layer for forming the pixel circuit,
the first capacitor electrode is formed as the lower auxiliary electrode layer, and the second capacitor electrode is formed as the active layer.
28 . The display device according to claim 27 , wherein
the transistor includes a driving transistor,
a first source electrode and a first drain electrode of the driving transistor are formed as the interlayer conductive layer, and
the first capacitor electrode and the second capacitor electrode of the storage capacitor and the first source electrode and the first drain electrode of the driving transistor are formed on different layers, respectively.
29 . The display device according to claim 28 , further comprising:
a sync conductive layer overlapping a first gate electrode of the driving transistor in a plan view and formed as the lower auxiliary electrode layer,
wherein the first capacitor electrode is electrically connected to the first source electrode and the sync conductive layer, and is electrically connected to an anode electrode of the light emitting element through a bridge pattern layer formed as the interlayer conductive layer.
30 . The display device according to claim 28 , further comprising: a data line electrically connected to the pixel circuit, wherein
the transistor further includes a switching transistor electrically connected to the data line, and
a direction in which the data line extends and a direction in which the well portion extends are parallel.