A thin film transistor included in a display device includes buffer layers on a substrate, an active pattern on the buffer layers, a gate electrode on the active pattern, a gate insulating layer between the active pattern and the gate electrode, and a source electrode and a drain electrode electrically connected to the active pattern and spaced apart in a first direction or a second direction crossing the first direction. The buffer layers include a first buffer layer contacting the active pattern, and a second buffer layer between the substrate and the first buffer layer, the first buffer layer has a first thickness in a third direction perpendicular to the first and second directions, the second buffer layer has a second thickness greater than the first thickness in the third direction, the first buffer layer includes silicon oxide (SiO.sub.x), and the second buffer layer does not include the silicon oxide.

A thin film transistor included in a display device includes buffer layers on a substrate, an active pattern on the buffer layers, a gate electrode on the active pattern, a gate insulating layer between the active pattern and the gate electrode, and a source electrode and a drain electrode electrically connected to the active pattern and spaced apart in a first direction or a second direction crossing the first direction. The buffer layers include a first buffer layer contacting the active pattern, and a second buffer layer between the substrate and the first buffer layer, the first buffer layer has a first thickness in a third direction perpendicular to the first and second directions, the second buffer layer has a second thickness greater than the first thickness in the third direction, the first buffer layer includes silicon oxide (SiO.sub.x), and the second buffer layer does not include the silicon oxide.

A display device, a tiled display device including the same, and an electronic device including the display device are provided. The display device including a substrate, a first pad electrode on the substrate, a second pad electrode spaced from the first pad electrode on the substrate, a light emitting element including a first electrode connected to the first pad electrode and a second electrode connected to the second pad electrode, a first power line spaced from the first pad electrode on the substrate, connected to a first side of the second pad electrode, and configured to receive a first source voltage, and a pad light blocking pattern overlapping a first gap between the first pad electrode and the first power line and a second gap between the second pad electrode and the first power line.

A display device includes a substrate; one or more buffer layers disposed on the substrate; an adhesive layer disposed on the buffer layer; a pixel driving circuit disposed on the adhesive layer; a protective layer which is disposed on the adhesive layer and of which a part is disposed on the pixel driving circuit; and a plurality of light-emitting elements electrically connected to the pixel driving circuit.

A display device includes a substrate; one or more buffer layers disposed on the substrate; an adhesive layer disposed on the buffer layer; a pixel driving circuit disposed on the adhesive layer; a protective layer which is disposed on the adhesive layer and of which a part is disposed on the pixel driving circuit; and a plurality of light-emitting elements electrically connected to the pixel driving circuit.

A display device includes a substrate; at least one pixel driving circuit disposed on the substrate; a plurality of bank patterns disposed on the pixel driving circuit; a plurality of light-emitting elements disposed on each of the plurality of bank patterns and electrically connected to the pixel driving circuit; at least one optical layer disposed to surround the plurality of light-emitting elements; and a black matrix disposed on the optical layer and overlapping at least one of the light-emitting elements, wherein the at least one optical layer includes a first optical layer, a second optical layer, and a third optical layer.

A display device includes a substrate; at least one pixel driving circuit disposed on the substrate; a plurality of bank patterns disposed on the pixel driving circuit; a plurality of light-emitting elements disposed on each of the plurality of bank patterns and electrically connected to the pixel driving circuit; at least one optical layer disposed to surround the plurality of light-emitting elements; and a black matrix disposed on the optical layer and overlapping at least one of the light-emitting elements, wherein the at least one optical layer includes a first optical layer, a second optical layer, and a third optical layer.

A display device includes a first pixel including a first sub-pixel, a second sub-pixel, and a third sub-pixel, wherein the first pixel is disposed in a first row, and a second pixel including a fourth sub-pixel, a fifth sub-pixel, and a sixth sub-pixel, the second pixel is disposed in the first row, the first sub-pixel and the fourth sub-pixel are adjacent to each other, emit light of a first color, and share a first data line, the second sub-pixel and the fifth sub-pixel are adjacent to each other, emit light of a second color, and share a second data line, and the sixth sub-pixel and the third sub-pixel are adjacent to each other, emit light of a third color, and share a third data line.

A display device includes a first pixel including a first sub-pixel, a second sub-pixel, and a third sub-pixel, wherein the first pixel is disposed in a first row, and a second pixel including a fourth sub-pixel, a fifth sub-pixel, and a sixth sub-pixel, the second pixel is disposed in the first row, the first sub-pixel and the fourth sub-pixel are adjacent to each other, emit light of a first color, and share a first data line, the second sub-pixel and the fifth sub-pixel are adjacent to each other, emit light of a second color, and share a second data line, and the sixth sub-pixel and the third sub-pixel are adjacent to each other, emit light of a third color, and share a third data line.

A display device and a manufacturing method thereof are provided. A display device includes a substrate, a pixel electrode and a common electrode spaced from each other on the substrate, a first reflective electrode on the pixel electrode and a second reflective electrode on the common electrode, respectively, a first bottom sacrificial electrode on the first reflective electrode and a second bottom sacrificial electrode on the second reflective electrode, an organic layer covering at least a portion of the first and second sacrificial electrodes, a light emitting element on the organic layer and including a semiconductor stack, a first contact electrode, and a second contact electrode, a first connection electrode connecting the pixel electrode and the first contact electrode and a second connection electrode connecting the common electrode and the second contact electrode and a first upper sacrificial electrode between the first contact electrode and the organic layer.