Pixel circuit configured to control light-emitting element

1 . A display device comprising;

a substrate made of polyimide, and

a plurality of pixels on the substrate,

wherein each of plurality of pixels includes a light-emitting element and a pixel circuit configured to control an amount of light-emitting current to the light-emitting element, and

wherein the pixel circuit includes:

a driving transistor having a pair of semiconductor regions of a first conductive type from among a p-type and an n-type;

a first switching transistor having a pair of semiconductor regions of a second conductive type from among the p-type and the n-type, and configured to connect or disconnect between a gate electrode and a drain of the driving transistor;

a second switching transistor having a pair of semiconductor regions of the second conductive type, and configured to supply a reset voltage to the gate electrode of the driving transistor;

a storage capacitor including a gate electrode of the driving transistor, an interlayer insulating layer covering the gate electrode of the driving transistor and an intermediate conductive layer disposed on the interlayer insulating layer; and

an auxiliary capacitor including a capacitor electrode disposed under the driving transistor to overlap an entire area of the gate electrode of the driving transistor in plan view, a semiconductor layer of the driving transistor and an insulating layer between the capacitor electrode and the semiconductor layer of the driving transistor,

wherein semiconductor layers of the first and second conductive types are formed in different layer positions.

2 . A display device according to claim 1 ,

wherein the first switching transistor has a dual gate structure that includes:

a bottom-gate electrode disposed on the interlayer insulating layer;

an oxide semiconductor layer over the bottom-gate electrode;

a second interlayer insulating layer disposed between the bottom-gate electrode and the oxide semiconductor layer;

a gate insulating layer over the oxide semiconductor layer; and

a top-gate electrode disposed on the gate insulating layer and overlapping the bottom-gate electrode when viewed planarly.

3 . A display device according to claim 2 , wherein the top-gate electrode and the bottom-gate electrode are driven at a same potential.

4 . A display device according to claim 1 , further comprising:

a third switching transistor having a pair of semiconductor regions of the first conductive type between a power supply line and the driving transistor, and

a fourth switching transistor having a pair of semiconductor regions of the first conductive type between the driving transistor and the light-emitting element,

wherein the first conductive type is the p-type and the second conductive type is the n-type.

5 . A display device according to claim 1 , further comprising:

a fifth switching transistor having the second conductive type and a dual-gate structure;

a sixth switching transistor having the second conductive type and the dual-gate structure; and

a seventh switching transistor having the second conductive type and the dual-gate structure, and configured to supply a reset voltage to an anode of the light-emitting element,

wherein the fifth switching transistor and the sixth switching transistor are connected in series between a data line and a source of the driving transistor, and

wherein the first conductive type is the p-type and the second conductive type is the n-type.

6 . A display device according to claim 1 , wherein the intermediate conductive layer and a bottom-gate electrode of the first switching transistor consists of parts of a same layer.

7 . A display device according to claim 1 , wherein the capacitor electrode of the auxiliary capacitor of each pixel circuit is connected to the capacitor electrodes of the auxiliary capacitors of pixel circuits arranged next to each other.