Displays with silicon and semiconducting oxide thin-film transistors
An electronic device may include a display having an array of display pixels on a substrate. The display pixels may be organic light-emitting diode display pixels or display pixels in a liquid crystal display. In an organic light-emitting diode display, hybrid thin-film transistor structures may be formed that include semiconducting oxide thin-film transistors, silicon thin-film transistors, and capacitor structures. The capacitor structures may overlap the semiconducting oxide thin-film transistors. Organic light-emitting diode display pixels may have combinations of oxide and silicon transistors. In a liquid crystal display, display driver circuitry may include silicon thin-film transistor circuitry and display pixels may be based on oxide thin-film transistors. A single layer or two different layers of gate metal may be used in forming silicon transistor gates and oxide transistor gates. A silicon transistor may have a gate that overlaps a floating gate structure.
1. A display pixel comprising:
a first power supply terminal;
a second power supply terminal;
a light-emitting diode coupled between the first and second power supply terminals;
a drive transistor coupled between the first power supply terminal and the light-emitting diode;
a first switching transistor that is coupled to a gate of the drive transistor, wherein the first switching transistor is an oxide transistor;
a capacitor that is directly coupled to a first node, wherein the first node is interposed between the first switching transistor and the gate of the drive transistor; and
a second switching transistor that is coupled between a signal line and an anode of the light-emitting diode, wherein the second switching transistor is a silicon transistor.
2. The display pixel defined in claim 1 , wherein the drive transistor is a silicon transistor.
3. The display pixel defined in claim 1 , wherein the second switching transistor is a p-type metal-oxide-semiconductor silicon transistor and the first switching transistor is an n-type metal-oxide-semiconductor oxide transistor.
4. The display pixel defined in claim 1 , wherein the capacitor is configured to store data signals from a data line.
5. The display pixel defined in claim 1 , wherein the first power supply terminal is a positive power supply terminal and wherein the second power supply terminal is a ground power supply terminal.
6. The display pixel defined in claim 1 , wherein the first switching transistor comprises a gate and a channel formed from a layer of semiconducting oxide and wherein the gate of the first switching transistor and the layer of semiconducting oxide are overlapping.
7. The display pixel defined in claim 6 , wherein the gate of the first switching transistor comprises molybdenum.
8. The display pixel defined in claim 6 , wherein the gate of the first switching transistor comprises molybdenum and a metal that is different from molybdenum.
9. The display pixel defined in claim 6 , wherein the gate of the first switching transistor comprises molybdenum and a refractory metal that is different from molybdenum.
10. The display pixel defined in claim 9 , wherein the refractory metal that is different from molybdenum comprises tungsten.
11. A display pixel comprising:
a first power supply terminal;
a second power supply terminal;
a drive transistor and a light-emitting diode that are connected in series between the first and second power supply terminals;
a first switching transistor that is coupled to a gate of the drive transistor, wherein the first switching transistor is an oxide transistor;
a signal line;
a second switching transistor that is coupled between the signal line and a first node that is interposed between the drive transistor and the light-emitting diode, wherein the second switching transistor is a silicon transistor; and
a capacitor coupled to a second node that is interposed between the first switching transistor and the gate of the drive transistor, wherein the second switching transistor is directly coupled between the signal line and the first node.
12. The display pixel defined in claim 11 , wherein the signal line is used to implement a compensation scheme to adjust for pixel-to-pixel variations in transistor performance.
13. The display pixel defined in claim 11 , wherein the drive transistor is a p-type metal-oxide-semiconductor silicon transistor.
14. The display pixel defined in claim 11 , wherein the second switching transistor is a p-type metal-oxide-semiconductor silicon transistor.