Patent ID: 12199110

DETAILED DESCRIPTION

Hereinafter the present disclosure will be further described in detail in conjunction with drawings and embodiments. It is to be understood that the embodiments set forth herein are intended to explain the present disclosure and not to limit the present disclosure. Additionally, it is to be noted that for ease of description, merely part, not all, of the structures related to the present disclosure are illustrated in the drawings.

FIG.1is a diagram showing structures of a display panel according to an embodiment of the present disclosure. As shown inFIG.1, a display panel100provided by the embodiment of the present disclosure includes a base substrate10, a first transistor20, a second transistor30, a first insulating layer40, and a second insulating layer41. The first transistor20and the second transistor30are formed on the base substrate10. The first transistor20includes a first active layer21, a first gate22, a first source23, and a first drain24. The first active layer21contains silicon. The second transistor30includes a second active layer31, a second gate32, a second source33, and a second drain34. The second active layer31contains an oxide semiconductor and is disposed on one side of the first active layer21facing away from the base substrate10. The first insulating layer40is disposed on one side of the second active layer31facing away from the base substrate10and between the second gate32and the second active layer31. The second insulating layer41is disposed on one side of the second active layer31facing towards the base substrate10. The concentration of oxygen in the first insulating layer40is lower than the concentration of oxygen in the second insulating layer41. The display panel100includes a pixel circuit (not shown inFIG.1) and a driver circuit50providing a drive signal for the pixel circuit. The driver circuit50includes at least one second transistor30.FIG.1is illustrated by using an example in which the driver circuit50includes both the first transistor20and the second transistor30.

The exemplary display panel100includes a display region AA and a non-display region NAA. The non-display region NAA is disposed on at least one side of the display region AA.FIG.1is illustrated by using an example in which the non-display region NAA is located on one side of the display region AA, where the driver circuit50is located in the non-display region NAA. The driver circuit50provides a drive signal for the pixel circuit (not shown inFIG.1) in the display region AA to cause the pixel circuit to drive a light-emitting element which is located in the same sub-pixel as the pixel circuit to emit light, thereby implementing the display of the display panel100.

It is to be noted that in the present application, the first transistor20and the second transistor30may be transistors in the driver circuit, that is, the driver circuit50includes the first transistor20or the second transistor30. Additionally, the first transistor20and the second transistor30may be transistors in the pixel circuit, that is, the pixel circuit includes the first transistor20or the second transistor30, for example, when the second transistor30is located in the pixel circuit, the second transistor30may be a drive transistor or a switch transistor.

The concentration defined in the present application, if not specially required, is the atomic concentration, that is, the atomic content per unit area.

The exemplary driver circuit50includes the first transistor20and the second transistor30, where the first transistor20may be a bottom-gate transistor or a top-gate transistor.FIG.1is illustrated by using an example in which the first transistor20is a top-gate transistor, that is, the first gate22is disposed on one side of the first active layer21facing away from the base substrate10. Additionally, the second insulating layer41is disposed on one side of the first gate22facing away from the base substrate10. The second active layer31is disposed on one side of the second insulating layer41facing away from the base substrate10. The first insulating layer40is disposed on one side of the second active layer facing away from the base substrate10. The second gate32is disposed on one side of the first insulating layer40facing away from the base substrate10. The first source23, the first drain24, the second source33, and the second drain34are all disposed on one side of the second gate32facing away from the base substrate10and are insulated from the second gate32. The first source23, the first drain24, the second source33, and the second drain34are disposed in the same layer so that the process steps can be simplified. Additionally, the first active layer21in the first transistor20contains silicon, optionally poly-silicon, that is, the first active layer21is a poly-silicon active layer such as a low temperature poly-silicon (LTPS) active layer. The second active layer31in the second transistor30includes an oxide semiconductor, that is, the second active layer31is an oxide semiconductor active layer such as an IGZO active layer. The LTPS thin-film transistor has the advantages of high carrier mobility, fast response, and low power consumption, and the oxide semiconductor thin-film transistor has the advantage of low leakage current. When the driver circuit50includes the first transistor20and the second transistor30, the driver circuit50has the advantages of high carrier mobility, fast response, low power consumption, and low leakage current, thereby ensuring the good performance of the driver circuit50and improving the display performance of the display panel100.

Furthermore, the concentration of oxygen in the first insulating layer40is lower than the concentration of oxygen in the second insulating layer41. On one hand, the concentration of oxygen in the first insulating layer40is appropriately reduced, so that when the first insulating layer40is used as a gate insulating layer, a deficiency caused by existence of a dangling bond in oxygen in the film forming process is avoided, and the problem that the existence of the deficiency affects the stability of the second transistor30is further avoided. On the other hand, the concentration of oxygen in the second insulating layer41is appropriately increased, so that the second active layer31containing the oxide semiconductor is supplemented with oxygen, and the normal function of the second active layer31is ensured. That is, in this embodiment, the concentration of oxygen in the first insulating layer40is lower than the concentration of oxygen in the second insulating layer41, so that the stability of the second transistor30can be improved without affecting the normal function of the second transistor30, thereby ensuring good performance of the driver circuit50.

It is to be noted that since the first insulating layer40is located on the side of the second active layer31facing away from the base substrate10and between the second gate32and the second active layer31and the second insulating layer41is located on the side of the second active layer31facing towards the base substrate10, the first insulating layer40and the second insulating layer41may be in direct contact with the second active layer31, which is shown inFIG.1. Alternatively, the first insulating layer40and/or the second insulating layer41may not be in direct contact with the second active layer31. That is, other insulating layers are provided between the first insulating layer40and the second active layer31without affecting the performance of the second transistor30, and/or other insulating layers are provided between the second insulating layer41and the second active layer31, which is not specifically limited in this embodiment.

In summary, the display panel provided by the embodiment of the present disclosure includes the first transistor and the second transistor. The first active layer of the first transistor contains silicon, and the second active layer of the second transistor contains an oxide semiconductor. The first insulating layer is located on the side of the second active layer facing away from the base substrate, and the second insulating layer is located on the side of the second active layer facing towards the base substrate. The concentration of oxygen in the first insulating layer is lower than the concentration of oxygen in the second insulating layer, that is, the concentration of oxygen in the first insulating layer is appropriately reduced, so that the second active layer is prevented from being affected by the deficiency in the first insulating layer; meanwhile, the concentration of oxygen in the second insulating layer is appropriately increased, so that the normal function of the second active layer is ensured. Therefore, the stability of the second transistor is improved, and the good performance of the driver circuit is ensured.

Optionally, A denotes a ratio of the concentration of oxygen to a concentration of silicon in the first insulating layer40, and B denotes a ratio of the concentration of oxygen to a concentration of silicon in the second insulating layer41, where A<B.

The first insulating layer40and the second insulating layer41each include oxygen and silicon, for example, silicon oxide, but the materials of the first insulating layer40and the second insulating layer41are not specifically limited in this embodiment, and those skilled in the art may select the materials according to actual situations, so long as the first insulating layer40and the second insulating layer41each include oxygen and silicon.

Oxygen atoms and silicon atoms in the first insulating layer40and the second insulating layer41need to be bonded. In this embodiment, the ratio of the concentration of oxygen to the concentration of silicon in the first insulating layer40is appropriately reduced, so that the phenomenon of existence of dangling bonds in oxygen in the film forming process of the first insulating layer40can be reduced, and the stability of the second transistor30can be ensured. Moreover, the phenomenon of existence of dangling bonds in oxygen is prevented from getting more serious when the ratio of the concentration of oxygen to the concentration of silicon is large, and thus deficiencies are prevented from getting more and capturing and affecting the carriers in the second transistor30. The problem of affecting the stability of the second transistor30is thus avoided.

Optionally, the first insulating layer40includes silicon oxide SiOx, and the second insulating layer41includes silicon oxide SiOy. Where x is a ratio of the number of oxygen atoms to the number of silicon atoms in the first insulating layer40, y is a ratio of the number of oxygen atoms to the number of silicon atoms in the second insulating layer41, and x<y. That is, when the first insulating layer40and the second insulating layer41each include silicon oxide, the ratio of the concentration of oxygen to the concentration of silicon in the first insulating layer40is appropriately reduced, so that the phenomenon of existence of dangling bonds in oxygen in the film forming process of the first insulating layer40can be reduced, and the stability of the second transistor30can be ensured. Moreover, the phenomenon of existence of dangling bonds in oxygen is prevented from getting more serious when the ratio of the concentration of oxygen to the concentration of silicon is large, and thus deficiencies are prevented from getting more and capturing and affecting the carriers in the second transistor30. The problem of affecting the stability of the second transistor30is thus avoided.

FIG.2is a diagram showing structures of a display panel according to another embodiment of the present disclosure. As shown inFIG.2, a pixel circuit60further includes a third transistor70. The third transistor70includes a third active layer71, a third source73, a third drain74, and a fourth gate72, and the third active layer71contains an oxide semiconductor. The display panel200further includes a fourth insulating layer43and a fifth insulating layer44. The fourth insulating layer43is disposed on one side of the third active layer71facing away from the base substrate10and between the third active layer71and the fourth gate72. The fifth insulating layer44is disposed on one side of the third active layer71facing towards the base substrate10. The concentration of oxygen in the fourth insulating layer43is lower than the concentration of oxygen in the fifth insulating layer44.FIG.4is illustrated by using an example in which the pixel circuit60includes the first transistor20.

As shown inFIG.2, the display panel200includes a display region AA and a non-display region NAA, the driver circuit50is disposed in the non-display region NAA, and the pixel circuit60is disposed in the display region AA. The pixel circuit60includes the first transistor20and the third transistor70. The third active layer71in the third transistor70includes an oxide semiconductor, that is, the third active layer71is an oxide semiconductor active layer such as an IGZO active layer. The leakage current of the oxide semiconductor thin-film transistor is very low, which can ensure that the leakage current in the working process of the pixel circuit60is low. The first active layer21in the first transistor20contains silicon, optionally poly-silicon, that is, the first active layer21is a poly-silicon active layer such as a low temperature poly-silicon (LTPS) active layer. Furthermore, the LTPS thin-film transistor has the advantages of high carrier mobility, fast response, and low power consumption. Therefore, when the pixel circuit60includes the first transistor20and the third transistor70, the pixel circuit60has the advantages of high carrier mobility, fast response, low power consumption, and low leakage current, thereby ensuring the good performance of the pixel circuit60and improving the display performance of the display panel200. In addition, in this embodiment, the second transistor30in the driver circuit50is an oxide semiconductor transistor and the third transistor70in the pixel circuit60is an oxide semiconductor transistor, so that good performance of the driver circuit50and the pixel circuit60is ensured, and the display performance of the display panel200is further improved.

Furthermore, in this embodiment, the concentration of oxygen in the fourth insulating layer43is lower than the concentration of oxygen in the fifth insulating layer44. On one hand, the concentration of oxygen in the fourth insulating layer43is appropriately reduced, so that when the fourth insulating layer43is used as a gate insulating layer, a deficiency caused by existence of a dangling bond in oxygen in the film forming process is avoided, and the problem that the existence of the deficiency affects the stability of the third transistor70is further avoided. On the other hand, the concentration of oxygen in the fifth insulating layer44is appropriately increased, so that the third active layer71containing the oxide semiconductor is supplemented with oxygen, and the normal function of the third active layer71is ensured. That is, in this embodiment, the concentration of oxygen in the fourth insulating layer43is lower than the concentration of oxygen in the fifth insulating layer44, so that the stability of the third transistor70can be improved without affecting the normal function of the third transistor70, thereby ensuring good performance of the pixel circuit60.

It is to be noted that the fourth insulating layer43may be disposed in the same layer as the first insulating layer40, and the fifth insulating layer44may be disposed in the same layer as the second insulating layer41; or the fourth insulating layer43is not disposed in the same layer as the first insulating layer40, and the fifth insulating layer44is not disposed in the same layer as the second insulating layer41.FIG.4is illustrated by using an example in which the fourth insulating layer43is disposed in the same layer as the first insulating layer40and the fifth insulating layer44is disposed in the same layer as the second insulating layer41. Additionally, in this embodiment, the third source73and the third drain74in the third transistor70are disposed in the same layer as the second source33and the second drain34in the second transistor30and the first source23and the first drain24in the first transistor20, thereby simplifying the process steps and improving the manufacturing efficiency of the display panel.

On the basis of the preceding scheme, optionally, the third transistor70is a switch transistor of the pixel circuit60, R1denotes a difference between a concentration C1of oxygen in the first insulating layer40and a concentration C2of oxygen in the second insulating layer41and satisfies R1=C2−C1, and R2denotes a difference between a concentration C4of oxygen in the fourth insulating layer43and a concentration C5of oxygen in the fifth insulating layer44is R2=C5−C4, where R1≥R2.

The pixel circuit60is sometimes applied to a low-frequency driving mode. When the pixel circuit60is applied to the low-frequency driving mode, a switch transistor in the pixel circuit60is in an off-state for a long time, while a transistor in the driver circuit50is turned on more frequently. In the driver circuit50, the difference between the concentration of oxygen in the first insulating layer40and the concentration of oxygen in the second insulating layer41is appropriately increased, that is, the concentration of oxygen in the first insulating layer40is lower, so that the influence of deficiencies on the second transistor30is reduced; the concentration of oxygen in the second insulating layer41is higher, so that the second active layer31is supplemented with sufficient oxygen, and the driver circuit50has high stability. Thus, even if the second transistor30in the driver circuit50turns on frequently, the overall characteristics of the driver circuit50can be ensured to be good.

Optionally, the third transistor70is a switch transistor of the pixel circuit60, and the concentration of oxygen in the first insulating layer40is lower than the concentration of oxygen in the fourth insulating layer43. That is, the concentration of oxygen in the first insulating layer in the second transistor30of the driver circuit50is much lower, so that when the first insulating layer40is used as the gate insulating layer, a deficiency caused by existence of a dangling bond in oxygen in the film forming process is avoided, and the problem that the existence of the deficiency affects the stability of the second transistor30is further avoided. Thus, the second transistor30is ensured to have high stability, and even if the second transistor30in the driver circuit50turns on frequently, the overall characteristics of the driver circuit50can also be ensured to be good.

It is to be noted that when the first insulating layer40and the fourth insulating layer43are disposed in the same film layer, for example, different concentrations of oxygen may be implanted into the first insulating layer40and the fourth insulating layer43by the ion implantation process so that the concentration of oxygen in the first insulating layer40is lower than the concentration of oxygen in the fourth insulating layer43.

Optionally, the third transistor70is a drive transistor of the pixel circuit60, R1denotes a difference between a concentration C1of oxygen in the first insulating layer40and a concentration C2of oxygen in the second insulating layer41and satisfies R1=C2−C1, and R2denotes a difference between a concentration C4of oxygen in the fourth insulating layer43and a concentration C5of oxygen in the fifth insulating layer44and satisfies R2=C5−C4, where R1≤R2.

The pixel circuit60is sometimes applied to a low-frequency driving mode. When the pixel circuit60is applied to the low-frequency driving mode, a drive transistor in the pixel circuit60is in an on state longer than a transistor in the driver circuit50. In the pixel circuit60, the difference between the concentration of oxygen in the fourth insulating layer43and the concentration of oxygen in the fifth insulating layer44is large, that is, the concentration of oxygen in the fourth insulating layer43is much lower, so that the influence of deficiencies on the third transistor70is reduced; the concentration of oxygen in the fifth insulating layer44is higher, so that the third active layer71is supplemented with sufficient oxygen, and the third transistor70is ensured to have high stability. Thus, even if the third transistor70in the pixel circuit60is in the on state for a long time, the overall characteristics of the pixel circuit60can also be ensured to be good.

Optionally, the third transistor70is a drive transistor of the pixel circuit60; the concentration of oxygen in the first insulating layer40is higher than the concentration of oxygen in the fourth insulating layer43. That is, the concentration of oxygen in the fourth insulating layer43in the third transistor70of the pixel circuit60is lower, so that when the fourth insulating layer43is used as the gate insulating layer, a deficiency caused by existence of a dangling bond in oxygen in the film forming process is avoided, and the problem that the existence of the deficiency affects the stability of the third transistor70is further avoided. Thus, the third transistor70is ensured to have high stability, and even if the third transistor70in the pixel circuit60is in the on state for a longer time, the overall characteristics of the pixel circuit60can also be ensured to be good. In this case, when the first insulating layer40and the fourth insulating layer43are disposed in the same film layer, different concentrations of oxygen may also be implanted into the first insulating layer40and the fourth insulating layer43by the ion implantation process so that the concentration of oxygen in the first insulating layer40is higher than the concentration of oxygen in the fourth insulating layer43.

FIG.3is a diagram showing structures of a display panel according to another embodiment of the present disclosure. As shown inFIG.3, the display panel300further includes a fourth transistor80. The fourth transistor80includes a fourth active layer81, a fourth source83, a fourth drain84, and a fifth gate82. The fourth active layer81contains an oxide semiconductor. The display panel300further includes a sixth insulating layer45and a seventh insulating layer46. The sixth insulating layer45is disposed on one side of the fourth active layer81facing away from the base substrate10and between the fourth active layer81and the fifth gate82. The seventh insulating layer46is disposed on one side of the fourth active layer81facing towards the base substrate10. The concentration of oxygen in the sixth insulating layer45is lower than the concentration of oxygen in the seventh insulating layer46.

It is to be noted that when the display panel300includes the fourth transistor80, the fourth transistor80may be a transistor in the driver circuit50or a transistor in the pixel circuit60, which is not specifically limited in this embodiment.FIG.3is illustrated by using an example in which the fourth transistor80is a transistor in the pixel circuit60. Additionally, the specific structure of the pixel circuit60is not limited in this embodiment. The pixel circuit60may include, for example, seven transistors (7T) or nine transistors (9T).

Specifically, the pixel circuit60further includes the fourth transistor80. The fourth active layer81in the fourth transistor80may also be an oxide semiconductor active layer such as an IGZO active layer. That is, the two transistors in the pixel circuit60in this embodiment are each an oxide semiconductor transistor, so that a leakage current is ensured in the working process of the pixel circuit60, and the performance of the pixel circuit60is ensured to be good. Additionally, in this embodiment, the concentration of oxygen in the sixth insulating layer45is lower than the concentration of oxygen in the seventh insulating layer46. On one hand, the concentration of oxygen in the sixth insulating layer45is appropriately reduced, so that when the sixth insulating layer45is used as a gate insulating layer, a deficiency caused by existence of a dangling bond in oxygen in the film forming process is avoided, and the problem that the existence of the deficiency affects the stability of the fourth transistor80is further avoided. On the other hand, the concentration of oxygen in the seventh insulating layer46is appropriately increased, so that the fourth active layer41containing the oxide semiconductor is supplemented with oxygen, and the normal function of the fourth active layer41is ensured. That is, in this embodiment, the concentration of oxygen in the sixth insulating layer45is lower than the concentration of oxygen in the seventh insulating layer46, so that the stability of the fourth transistor80can be improved without affecting the normal function of the fourth transistor80, thereby ensuring good performance of the pixel circuit60.

It is to be noted that the sixth insulating layer45, the fourth insulating layer43, and the first insulating layer40may be disposed in the same film layer or different film layers, or any two of the above layers may be disposed in the same film layer. Similarly, the seventh insulating layer46, the fifth insulating layer44, and the second insulating layer41may be disposed in the same film layer or different film layers, or any two of the above layers may be disposed in the same film layer.FIG.3is illustrated by using an example in which the sixth insulating layer45, the fourth insulating layer43, and the first insulating layer40are disposed in the same layer and the seventh insulating layer46, the fifth insulating layer44, and the second insulating layer41are disposed in the same layer. Additionally, in this embodiment, the fourth source83and the fourth drain84in the fourth transistor80are disposed in the same layer as the third source73and the third drain74in the third transistor70, the second source33and the second drain34in the second transistor30, and the first source23and the first drain24in the first transistor30, thereby simplifying the process steps and improving the manufacturing efficiency of the display panel.

On the basis of the preceding scheme, optionally, the third transistor70is a drive transistor of the pixel circuit60, and the fourth transistor80is a switch transistor of the pixel circuit60. Where R2denotes a difference between a concentration C4of oxygen in the fourth insulating layer43and a concentration C5of oxygen in the fifth insulating layer44and satisfies R2=C5−C4, and R3denotes a difference between a concentration C6of oxygen in the sixth insulating layer45and a concentration C7of oxygen in the seventh insulating layer46and satisfies R3=C7−C6, where R2≥R3.

Generally speaking, in a pixel circuit, a transistor having a gate connected to a scan signal or a light emission control signal is a switch transistor, transistors except the switch transistor in the pixel circuit are drive transistors which are connected in series on the transmission path between a first power signal (e.g. PVDD signal) and a second power signal (e.g. PVEE signal), and a data signal is written into the gate of the drive transistor. As the data signal is written, the potential of the gate of the drive transistor changes. The pixel circuit is sometimes applied to a low-frequency driving mode. When the pixel circuit is applied to the low-frequency driving mode, a drive transistor is in an on state longer than a switch transistor in the pixel circuit. In the pixel circuit60in this embodiment, the difference between the concentration of oxygen in the fourth insulating layer43and the concentration of oxygen in the fifth insulating layer44is large, that is, the concentration of oxygen in the fourth insulating layer43is lower, so that the influence of deficiencies on the third transistor70is reduced. The concentration of oxygen in the fifth insulating layer44is higher, so that the third active layer71is supplemented with sufficient oxygen, and the third transistor70is ensured to have high stability. Thus, even if the third transistor70in the pixel circuit60is in the on state for a long time, the overall characteristics of the pixel circuit60can also be ensured to be good.

Optionally, the third transistor70is a drive transistor of the pixel circuit60, and the fourth transistor80is a switch transistor of the pixel circuit60. The concentration of oxygen in the fourth insulating layer43is lower than the concentration of oxygen in the sixth insulating layer45. That is, the concentration of oxygen in the fourth insulating layer43in the third transistor70of the pixel circuit60is lower, so that when the fourth insulating layer43is used as the gate insulating layer, a deficiency caused by existence of a dangling bond in oxygen in the film forming process is avoided, and the problem that the existence of the deficiency affects the stability of the third transistor70is further avoided. Thus, the third transistor70is ensured to have high stability, and even if the third transistor70in the pixel circuit60is in the on state for a longer time, the overall characteristics of the pixel circuit60can also be ensured to be good. Similarly, when the fourth insulating layer43and the sixth insulating layer45are disposed in the same film layer, the concentration of oxygen in the fourth insulating layer43may be made different from the concentration of oxygen in the sixth insulating layer45by the ion implantation process.

Optionally, with continued reference toFIG.1, the display panel100further includes a third insulating layer42disposed on one side of the second gate32facing away from the base substrate10, where a concentration of oxygen in the third insulating layer42is higher than the concentration of oxygen in the first insulating layer40.

The third insulating layer42is an insulating layer on the side of the second gate32facing away from the base substrate10. The concentration of oxygen in the third insulating layer42is appropriately increased, so that the density of the third insulating layer42is increased. Therefore, the second transistor30is protected by the third insulating layer42, and external water and oxygen, hydrogen and other elements are prevented from entering the second transistor30to affect the performance of the second transistor30.

Optionally, A denotes a ratio of the concentration of oxygen to a concentration of silicon in the first insulating layer40, and C denotes a ratio of the concentration of oxygen to a concentration of silicon in the third insulating layer42, where A<C. When the first insulating layer40and the second insulating layer41each include oxygen and silicon, the ratio of the concentration of oxygen to the concentration of silicon in the third insulating layer42is increased, so that the second transistor30is protected, avoiding a reduction in the density of the third insulating layer42due to too low a concentration of oxygen and too high a concentration of silicon in the third insulating layer42, thereby avoiding influence on the ability of the third insulating layer42to protect the second transistor30.

Optionally, the concentration of oxygen in the third insulating layer42is lower than the concentration of oxygen in the second insulating layer41. That is, the concentration of oxygen in the third insulating layer42is higher than the concentration of oxygen in the first insulating layer so as to protect the second transistor30, but compared with the concentration of oxygen in the second insulating layer41, the concentration of oxygen in the third insulating layer42is still lower than the concentration of oxygen in the second insulating layer414. That is, the concentration of oxygen in the second insulating layer41is higher, so that the second active layer31including the oxide semiconductor is supplemented with oxygen, and the normal function of the second active layer31is ensured.

Optionally, B denotes a ratio of the concentration of oxygen to a concentration of silicon in the second insulating layer41, and C denotes a ratio of the concentration of oxygen to a concentration of silicon in the third insulating layer42, where B>C. That is, when the second insulating layer41and the third insulating layer42each include oxygen and silicon, the ratio of the concentration of oxygen to the concentration of silicon in the second insulating layer41is increased, so that the second active layer31including the oxide semiconductor is supplemented with oxygen, and the normal function of the second active layer31is ensured.

Optionally, A denotes a ratio of the concentration of oxygen to a concentration of silicon in the first insulating layer40, B denotes a ratio of the concentration of oxygen to a concentration of silicon in the second insulating layer41, and C denotes a ratio of the concentration of oxygen to a concentration of silicon in the third insulating layer42, where (B−1)≤2(C−1)−(A−1). That is, (B−1)≤2(C−1)−(A−1), so that the concentration of oxygen to a concentration of silicon in the first insulating layer40is lower, and thus the stability of the second transistor30can be improved. A deficiency is avoided caused by existence of a dangling bond in oxygen in the film forming process when the first insulating layer40is used as a gate insulating layer, and the problem that the existence of the deficiency affects the stability of the second transistor30is further avoided.

On the basis of the preceding scheme, optionally, (B−1)−(C−1)≤½×[(C−1)−(A−1)].

In this embodiment, the ratio of the concentration of oxygen to the concentration of silicon in the first insulating layer40, the ratio B of the concentration of oxygen to the concentration of silicon in the second insulating layer41, and the ratio C of the concentration of oxygen to the concentration of silicon in the third insulating layer42satisfy that (B−1)−(C−1)≤½×[(C−1)−(A−1)]. Therefore, a deficiency caused by existence of a dangling bond in oxygen in the film forming process of the first insulating layer40is reduced, and the problem that the existence of the deficiency affects the stability of the second transistor30is avoided. Meanwhile, the second active layer31containing the oxide semiconductor is supplemented with oxygen through the second insulating layer41, and the normal function of the second active layer31is ensured. Moreover, the density of the third insulating layer42is increased through the sufficient oxygen to protect the second transistor30and further improve the stability of the second transistor30.

It is to be understood that the preceding example is merely illustrated with the setting of concentrations of oxygen in the first insulating layer40, the second insulating layer41, and the third insulating layer43close to the second transistor30. However, when the display panel100further includes the third transistor70and the fourth transistor80, for example, with continued reference toFIG.3, the preceding rule is also applicable to the fourth insulating layer43, the fifth insulating layer44, and the insulating layer47on the side of the fourth insulating layer43facing away from the fifth insulating layer44, and the preceding rule is also applicable to the sixth insulating layer45, the seventh insulating layer46, and the insulating layer48on the side of the sixth insulating layer45facing away from the seventh insulating layer46. Repetition is not made herein.

The preceding embodiments are each illustrated by using an example in which the second transistor30is a top-gate transistor. Optionally, the second transistor30may also be a double-gate transistor. When the second transistor30is a double-gate transistor, in addition to satisfying the rule of the concentration of oxygen in the insulating layer described in the preceding embodiments, the second transistor30may also be individually set according to the characteristics of the double-gate transistor.

FIG.4is a diagram showing structures of a display panel400according to another embodiment of the present disclosure. As shown inFIG.4, the second transistor30includes a third gate35disposed on one side of the second insulating layer41facing towards the base substrate10, where a thickness H1of the first insulating layer40is less than a thickness H2of the second insulating layer41.

Specifically, the second transistor30includes not only the second gate32but also the third gate35, that is, the second transistor30is a double-gate transistor, so that the mobility of carriers in the second transistor30can be enhanced, and the response ability of the second transistor30can be enhanced. It is to be noted that the second transistor30may be an oxide semiconductor transistor and generally speaking, the volume of the oxide semiconductor transistor is large, so it is beneficial to reducing the volume of the second transistor30by providing the second transistor30as a double-gate transistor with a top gate and a bottom gate stacked. The area of the non-display region NAA where the driver circuit50is located is thus reduced, achieving the narrow bezel of the display panel100. Additionally, the thickness H1of the first insulating layer40is less than the thickness H2of the second insulating layer41, that is, the thickness of the insulating layer of a main gate is less than the thickness of the insulating layer of an assist gate, so that the ability of the main gate to control the second transistor30is ensured.

When the second transistor30includes the third gate35located on the side of the second insulating layer41facing towards the base substrate10, optionally, in the second insulating layer41, the concentration of oxygen on the side facing towards the second active layer31is higher than the concentration of oxygen on the side facing away from the second active layer31.

Such setting has the following advantages: on one hand, in the second insulating layer41, the concentration of oxygen on the side facing towards the second active layer31is higher so that the second active layer31containing the oxide semiconductor is supplemented with sufficient oxygen and the normal function of the second active layer31is ensured; on the other hand, in the second insulating layer41, the concentration of oxygen on the side facing away from the second active layer31is lower so that a deficiency caused by existence of a dangling bond in oxygen in the film forming process of the second insulating layer41is avoided, and the problem that the existence of the deficiency affects the stability of the second transistor30is further avoided. Thus, the second transistor30is ensured to have good performance.

On the basis of the preceding scheme,FIG.5is a diagram showing structures of a display panel500according to another embodiment of the present disclosure. As shown inFIG.5, the second insulating layer41includes a first sub-insulating layer411and a second sub-insulating layer412, the second sub-insulating layer412is disposed on one side of the first sub-insulating layer411facing away from the second active layer31, and the first sub-insulating layer411and the second sub-insulating layer412each contains silicon oxide, where a concentration of oxygen in the first sub-insulating layer411is higher than a concentration of oxygen in the second sub-insulating layer412.

In this embodiment, the first sub-insulating layer411and the second sub-insulating layer412each includes silicon oxide, but concentrations of oxygen in the first sub-insulating layer411and the second sub-insulating layer412are different, for example, the concentration of oxygen in the first sub-insulating layer411is higher than the concentration of oxygen in the second sub-insulating layer412. That is, the concentration of oxygen in the first sub-insulating layer411is appropriately increased, so that the second active layer31including the oxide semiconductor is supplemented with sufficient oxygen and the normal function of the second active layer31is ensured. Meanwhile, the concentration of oxygen in the second sub-insulating layer412is appropriately reduced so that a deficiency caused by existence of a dangling bond in oxygen in the film forming process of the second sub-insulating layer412is avoided, and the problem that the existence of the deficiency affects the stability of the second transistor30is further avoided. Thus, the second transistor30is ensured to have good performance.

On the basis of the preceding scheme, optionally, a concentration of hydrogen in the second sub-insulating layer412is higher than a concentration of hydrogen in the first sub-insulating layer411. The deficiency caused by existence of a dangling bond in oxygen inside the second sub-insulating layer412is repaired by hydrogen in the second sub-insulating layer412, so that the stability of the second transistor30is ensured, and the performance of the second transistor30is further improved.

It is to be noted thatFIG.5is illustrated by merely using an example in which the second transistor30is a double-gate transistor. In this manner, inFIG.5, the relationship between the thickness H1of the first insulating layer40and the thickness H2of the second insulating layer41is described, the variation in the concentration of oxygen in the second insulating layer41is described, and when the second insulating layer41includes the first sub-insulating layer411and the second sub-insulating layer412, the materials of and the concentration relationship of oxygen in the first sub-insulating layer411and the second sub-insulating layer412are defined, and the concentration relationship of hydrogen in the first sub-insulating layer411and the second sub-insulating layer412is defined. It is to be understood that when the third transistor70is a double-gate transistor, the fourth insulating layer43and the fifth insulating layer44also satisfy the preceding relationship. When the fourth transistor80is a double-gate transistor, the sixth insulating layer45and the seventh insulating layer46also satisfy the preceding relationship. Repetition is not made herein.

On the basis of the preceding schemes,FIG.6is a diagram showing structures of a display panel600according to another embodiment of the present disclosure. As shown inFIG.6, the base substrate10in the embodiment of the present disclosure may be a flexible base substrate or a rigid base substrate, which is not limited in the embodiment of the present disclosure. When the base substrate10is a flexible substrate, the base substrate10may include a polyimide substrate to ensure that the flexible substrate has good high temperature resistance and good insulation performance. The base substrate10may include one layer of polyimide substrate or two layers of polyimide substrates, which is not limited in the embodiment of the present disclosure. When the base substrate10includes one layer of polyimide substrate, the film layer of the base substrate10has a simple structure and can be manufactured with a simple process, facilitating the implementation of design requirements of the base substrate10and the entire display panel being light and thin. When the base substrate10includes at least two layers of polyimide substrates, a buffer layer is further provided between the polyimide substrates to enhance adhesion between the polyimide substrates; when the base substrate10is formed by polyimide substrates being stacked with the buffer layer, some external impurities and/or water vapor can be prevented from entering into the substrate on the bottom to affect the first active layer21. Furthermore, since the polyimide substrate is generally manufactured on a rigid substrate, the rigid substrate is generally lift off by the laser lift-off technique after the driver circuit50, the pixel circuit, and the light-emitting element are manufactured on the base substrate10. The polyimide substrate may be damaged when the rigid substrate is lift off by laser. Therefore, when the base substrate10includes at least two polyimide substrates, for example, including a first polyimide substrate and a second polyimide substrate, a first buffer layer is provided between the first polyimide substrate and the second polyimide substrate, and a second buffer layer is provided between the second polyimide substrate and the first active layer21. The first polyimide substrate is manufactured on the rigid substrate, and the driver circuit50and the pixel circuit are manufactured on the second buffer layer. Therefore, even if the first polyimide substrate may be damaged when the rigid substrate is lift off by laser, the integrity of the second polyimide substrate and the integrity of the second buffer layer on the second polyimide substrate can be ensured, thereby ensuring the integrity of the entire display panel.FIG.6is illustrated by merely using an example in which the base substrate10is a flexible substrate and includes a first flexible substrate11and a second flexible substrate13, which are polyimides, respectively, as well as a first buffer layer12between the first flexible substrate11and the second flexible substrate13and a second buffer layer14between the second flexible substrate13and the first active layer21.

Based on the same concept, an embodiment of the present disclosure further provides a display panel.FIG.7is a diagram showing structures of a display panel700according to another embodiment of the present disclosure. As shown inFIG.7, display panel700provided by the embodiment of the present disclosure includes a base substrate10, a first transistor20, a second transistor30, a first insulating layer40, and a second insulating layer41. The first transistor20and the second transistor30are formed on the base substrate10. The first transistor20includes a first active layer21, a first gate22, a first source23, and a first drain24. The first active layer21contains silicon. The second transistor30includes a second active layer31, a second gate32, a third gate35, a second source33, and a second drain34. The second active layer31contains an oxide semiconductor and is disposed on one side of the first active layer21facing away from the base substrate10. The first insulating layer40and the second insulating layer42are located on two sides of the second active layer31, respectively. The first insulating layer40is disposed between the second gate32and the second active layer31. The second insulating layer41is disposed between the third gate35and the second active layer31. The thickness H1of the first insulating layer40is less than the thickness H2of the second insulating layer41. The concentration of oxygen in the first insulating layer40is lower than the concentration of oxygen in the second insulating layer41. The display panel700includes a pixel circuit (not shown inFIG.7) and a driver circuit50providing a drive signal for the pixel circuit. The driver circuit50includes at least one second transistor30.FIG.7is illustrated by using an example in which the driver circuit50includes the first transistor20and the second transistor30.

Referring toFIG.7, when the second gate32is the main gate of the second transistor and is the top gate of the second transistor30, the thickness H1of the first insulating layer40corresponding to the main gate is set to be less than the thickness H2of the second insulating layer41corresponding to the assist gate, thereby ensuring the ability of the main gate to control the second transistor30.

FIG.8is a diagram showing structure of a display panel800according to another embodiment of the present disclosure. As shown inFIG.8, when the second gate32is the main gate of the second transistor30and is the bottom gate of the second transistor30, the thickness H1of the first insulating layer40corresponding to the main gate is set to be less than the thickness H2of the second insulating layer41corresponding to the assist gate to ensure the ability of the main gate to control the second transistor30.

In the display panel provided by the embodiment of the present disclosure, the concentration of oxygen in the first insulating layer (that is, the insulating layer of the main gate) is lower than the concentration of oxygen in the second insulating layer (that is, the insulating layer of the assist gate), that is, the concentration of oxygen in the first insulating layer is appropriately reduced to avoid the influence of the deficiency in the first insulating layer on the second active layer. The concentration of oxygen in the second insulating layer is appropriately increased to ensure the normal function of the second active layer, thereby improving the stability of the second transistor and ensuring the good performance of the driver circuit. Meanwhile, the thickness of the first insulating layer (that is, the insulating layer of the main gate) is set to be less than the thickness of the second insulating layer (that is, the insulating layer of the assist gate) to ensure the ability of the main gate to control the second transistor.

Based on the same concept, an embodiment of the present disclosure further provides a display device. The display device includes any display panel provided in the preceding embodiments. Exemplarily, as shown inFIG.9, a display device1000includes the display panel100. Therefore, the display device also has the beneficial effects of the display panel described in the preceding embodiments, and for the same details, reference may be made to the description of the preceding display panel, and repetition will not made herein.

A display device1000provided in accordance with the embodiments of the present disclosure may be the phone shown inFIG.9, or may be any electronic product with a display function, including but not limited to: televisions, laptops, desktop displays, tablet computers, digital cameras, smart bracelets, smart glasses, in-vehicle displays, industry-controlling equipment, medical displays, touch interactive terminals, etc., which will not be specifically limited in the embodiment of the present disclosure.

It is to be noted that the preceding are merely preferred embodiments of the present disclosure and the technical principles used therein. It is to be understood by those skilled in the art that the present disclosure is not limited to the embodiments described herein. Those skilled in the art can make various apparent modifications, adaptations, and substitutions without departing from the scope of the present disclosure. Therefore, while the present disclosure has been described in detail via the preceding embodiments, the present disclosure is not limited to the preceding embodiments and may include equivalent embodiments without departing from the concept of the present disclosure. The scope of the present disclosure is determined by the scope of the appended claims.