Display substrate with improved carrier mobility of thin film transistors within GOA region
The present disclosure relates to the field of display technology, and provides a display substrate, its manufacturing method, and a display device. The display substrate includes a display region and a GOA region. An active layer of a TFT at the GOA region at least includes a first oxide semiconductor layer and a second oxide semiconductor layer arranged on the first oxide semiconductor layer, and the first oxide semiconductor layer is arranged between the second oxide semiconductor layer and a base substrate of the display substrate and has a carrier mobility of smaller than the second oxide semiconductor layer.
1. A display substrate, comprising a display region and a gate driver on array (GOA) region, wherein an active layer of a thin film transistor (TFT) at the GOA region at least comprises a first oxide semiconductor layer and a second oxide semiconductor layer arranged on the first oxide semiconductor layer, and the first oxide semiconductor layer is arranged between the second oxide semiconductor layer and a base substrate of the display substrate and has a carrier mobility of smaller than the second oxide semiconductor layer,
wherein an active layer of a TFT at the display region merely comprises the first oxide semiconductor layer.
2. The display substrate according to claim 1 , wherein the carrier mobility of the second oxide semiconductor layer is more than 30 cm 2 /(V·S).
3. The display substrate according to claim 1 , wherein the second oxide semiconductor layer is made of IGZYO or IGTO, where Y represents Sn.
4. The display substrate according to claim 3 , wherein a content of In is six times of a content of Ga in the second oxide semiconductor layer, and a content of O accounts for 10% to 35%.
5. The display substrate according to claim 4 , wherein contents of elements in IGZYO meet an equation of In:Ga:Zn:Sn=6:1:4:1.
6. The display substrate according to claim 1 , wherein the first oxide semiconductor layer is made of IGZO.
7. The display substrate according to claim 1 , wherein the first oxide semiconductor layer has a thickness of 300 to 500 Å.
8. The display substrate according to claim 1 , wherein the TFT is a top-gate TFT.
9. The display substrate according to claim 1 , wherein the second oxide semiconductor layer has a thickness of 300 to 500 Å.
10. The display substrate according to claim 1 , wherein the TFT at the GOA region has a carrier mobility within a range from 20.5 cm 2 /(V·S) to 30.2 cm 2 /(V·S).
11. A display device, comprising a display substrate, the display substrate comprising a display region and a gate driver on array (GOA) region, wherein an active layer of a thin film transistor (TFT) at the GOA region at least comprises a first oxide semiconductor layer and a second oxide semiconductor layer arranged on the first oxide semiconductor layer, and the first oxide semiconductor layer is arranged between the second oxide semiconductor layer and a base substrate of the display substrate and has a carrier mobility of smaller than the second oxide semiconductor layer,
wherein an active layer of a TFT at the display region merely comprises the first oxide semiconductor layer.
12. The display device according to claim 11 , wherein the display device is an Organic Light-Emitting Diode (OLED) display device.
13. A method for manufacturing a display substrate, the display substrate comprising a display region and a GOA region, the method comprising:
forming a first oxide semiconductor layer and a second oxide semiconductor layer sequentially at the GOA region;
patterning the second oxide semiconductor layer and the first oxide semiconductor layer to form an active layer of a TFT; and
forming an active layer of a TFT at the display region by the first oxide semiconductor layer,
wherein the first oxide semiconductor layer has a carrier mobility smaller than the second oxide semiconductor layer.
14. The display device according to claim 11 , wherein the carrier mobility of the second oxide semiconductor layer is more than 30 cm 2 /(V·S).
15. The display device according to claim 11 , wherein the second oxide semiconductor layer is made of IGZYO or IGTO, where Y represents Sn.
16. The display device according to claim 15 , wherein a content of In is six times of a content of Ga in the second oxide semiconductor layer, and a content of O accounts for 10% to 35%.
17. The display device according to claim 16 , wherein contents of elements in IGZYO meet an equation of In:Ga:Zn:Sn=6:1:4:1.