Pixel driving circuit, driving substrate and display device

Abstract

This application provides a pixel driving circuit, a driving substrate, and a display device. The method includes: a field-effect transistor (FET), including a gate and a source; and a drift correction component electrically connected between the gate and the source. The drift correction component is configured to generate a gate-source voltage difference between the gate and the source to correct the drift of the threshold voltage of the FET. This solution can maintain a gate-source voltage difference between the gate and the source that is equivalent to the on-state voltage difference, thereby maintaining the threshold voltage at a certain degree of positive bias and avoiding the phenomenon of the threshold voltage being excessively negatively biased.

Description

TECHNICAL FIELD

[0001] Embodiments of the present application relate to the technical field, and particularly, to a pixel driving circuit, a driving substrate and a display device. BACKGROUND

[0002] In a related pixel driving circuit, due to its working environment, for example, high temperature environment, low temperature environment, or water vapor environment, etc., will cause the drift of transistor, especially the threshold voltage of the field effect transistor, which is often embodied in the threshold voltage of the turned-on field effect transistor becomes lower and lower, that is, the phenomenon of negative shift of threshold voltage.

[0003] Therefore, there is a need for a solution that can avoid the negative shift of threshold voltage. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a pixel driving circuit, a driving substrate and a display device.

[0005] To achieve the above purpose, the present application provides a pixel driving circuit, comprising:

[0006] a field effect transistor comprising a gate and a source;

[0007] a drift correction component electrically connected between the gate and the source; the drift correction component is configured to generate a gate-source voltage difference between the gate and the source to correct the drift of the threshold voltage of the field effect transistor.

[0008] Further, the drift correction component comprises:

[0009] at least one of a capacitor and a diode;

[0010] Further, the hole-electron type semiconductor comprises a hole region and an electron region; the hole region is electrically connected to the gate, and the electron region is electrically connected to the source.

[0011] The diode is configured to be turned on when the gate-source voltage difference reaches a preset turn-on voltage difference.

[0012] Further, the field effect transistor further comprises a drain; the field effect transistor is configured to control the source and the drain to be turned on when the gate voltage is greater than the threshold voltage, and to control the source and the drain to be turned off when the gate voltage is less than or equal to the threshold voltage.

[0013] Further, the field effect transistor is further configured such that the threshold voltage is greater than the gate voltage when the diode is turned on.

[0014] Further, the field effect transistor is further configured to inhibit the holes on the side of the gate of the field effect transistor from repelling, so as to maintain the gate-source voltage difference greater than zero; and maintain the threshold voltage greater than zero in the state that the gate-source voltage difference is greater than zero.

[0015] Based on the same inventive concept, the application further provides a driving substrate, comprising the pixel driving circuit according to any one of the above.

[0016] Based on the same inventive concept, the application further provides a display device, comprising the driving substrate according to the above.

[0017] From the above, the pixel driving circuit, the driving substrate and the display device provided by the application are based on the conductive characteristics between the hole region and the electron region of the hole-electron semiconductor, comprehensively consider the gate-source voltage difference between the gate and the source, and parallelly connect the hole-electron semiconductor, so that when the hole-electron semiconductor is turned on, the gate-source voltage difference between the gate and the source is equivalent to the turn-on voltage difference, and the gate-source voltage difference is greater than 0, that is, the potential of the gate is higher than that of the source and the drain, so as to maintain the threshold voltage to be positively biased to a certain extent, and avoid the phenomenon that the threshold voltage is excessively negatively biased. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the application or the related art, the following will briefly introduce the drawings needed to be used in the embodiments or the related art description. Obviously, the drawings in the following description are only embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0019] Figure 1 It is a first circuit diagram of the pixel driving circuit of the embodiment of the application;

[0020] Figure 2 It is a first characteristic diagram of the pixel driving circuit of the embodiment of the application;

[0021] Figure 3 It is a second circuit diagram of the pixel driving circuit of the embodiment of the application;

[0022] Figure 4 It is a third circuit diagram of the pixel driving circuit of the embodiment of the application;

[0023] Figure 5 It is a fourth circuit diagram of the pixel driving circuit of the embodiment of the application;

[0024] Figure 6 It is a fifth circuit diagram of the pixel driving circuit of the embodiment of the application;

[0025] Figure 7 This is a second characteristic diagram of the pixel driving circuit according to an embodiment of this application;

[0026] Figure 8 This is a circuit diagram of the driving substrate according to an embodiment of this application. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with specific embodiments and the accompanying drawings.

[0028] It should be noted that, unless otherwise defined, the technical or scientific terms used in the embodiments of this application should have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," and similar terms used in the embodiments of this application do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are only used to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0029] As described in the background section, the relevant pixel driving circuits are still difficult to meet the needs of products in actual use.

[0030] In the process of developing this application, the applicant discovered that the main problem with the relevant pixel driving circuit is that, due to the influence of its operating environment, such as high temperature, low temperature, or moisture environment, the characteristics of transistors, especially field-effect transistors, drift, resulting in issues such as long-term reliability or high / low temperature reliability. Specifically, in Figure 1 The pixel driving circuit shown includes a field-effect transistor 100 and a voltage signal input terminal 200. The field-effect transistor 100 can be a metal-oxide-semiconductor field-effect transistor, a modulation-doped field-effect transistor, or a metal-semiconductor field-effect transistor. The voltage at the voltage signal input terminal 200 is the gate voltage applied to the gate 101.

[0031] The field-effect transistor 100 includes three ports: a gate 101, a source 102, and a drain 103. When the voltage signal received by the gate 101 reaches the threshold voltage of the field-effect transistor 100, the source 102 and the drain 103 are turned on.

[0032] one or more of the above Figure 1 The field-effect transistors 100 in the GOA (gate drive integrated array substrate) are used to form a GOA, and the high and low temperature reliability and long-term reliability of the GOA are tested to determine the impact of high temperature and low temperature environments on the long-term reliability of the GOA.

[0033] Specifically, the operating environment temperature of in-vehicle screen products can be simulated by placing the GOA in a high-temperature environment of ≥85 degrees Celsius and / or a low-temperature environment of ≤-40 degrees Celsius for a long-term reliability test of 700 hours.

[0034] Based on this, any number of field-effect transistors 100 in GOA can be selected to draw, as shown below. Figure 2 The characteristic diagram shown is as follows. Figure 2 The change in threshold voltage of field-effect transistor 100 after 700 hours of testing is shown.

[0035] The horizontal axis represents the threshold voltage when the source 102 and drain 103 are turned on, and the vertical axis represents the drain current. Each curve represents the characteristic curve of a single field-effect transistor 100. Under normal operating conditions, the threshold voltage should be maintained near 0V, for example, 3V, 5V, -20V, or -10V. It can be seen that after 700 hours of long-term reliability testing, the threshold voltage drift correction is as low as -20V to -40V. That is to say, the threshold voltage of the field-effect transistor 100 has a negative drift of about -20V.

[0036] The applicant also discovered in the research that when the gate voltage applied to the gate 101 reaches the threshold voltage, the IGZO (insulating layer) of the field-effect transistor 100 will become conductive, which will cause the gate voltage of the gate 101 to be consistent with the source voltage of the source 102. This will cause empty holes to attract and repel electrons around the gate 101 in the IGZO, and the voltage required to turn on the source 102 and the drain 103 will become lower. After the threshold voltage is negatively drifted, the voltage required to turn on the drain 103 and the source 102 will continue to decrease and will continue to intensify, that is, the threshold voltage will be negatively drifted, to the point that a gate voltage of -20V or even -40V can turn on the source 102 and the drain 103. Therefore, the current switching ratio between the drain 103 and the source 102 changes and is in a state of flux for a long time. This is equivalent to applying a DC bias voltage to the field-effect transistor, which causes the drain current of the drain 103 to increase, and the voltage of the drain 103 cannot be maintained, and the field-effect transistor 100 malfunctions.

[0037] Based on this, one or more embodiments of this application provide a pixel driving circuit that, based on a PN junction (hole-electron semiconductor), maintains the threshold voltage required to turn on the transistor greater than zero.

[0038] The embodiments of this application are described in detail below with reference to the accompanying drawings.

[0039] refer to Figure 3 One embodiment of the pixel driving circuit of this application includes:

[0040] The field-effect transistor 100 includes a gate 101 and a source 102;

[0041] A drift correction component 400 is electrically connected between the gate 101 and the source 102; the drift correction component 400 is configured to generate a gate-source voltage difference between the gate 101 and the source 102 to correct the drift of the threshold voltage of the field-effect transistor 100.

[0042] In this embodiment, with Figure 3 The pixel driving circuit shown is a specific example, which includes a field-effect transistor 100 and a drift correction component 400, wherein the field-effect transistor 100 includes a gate 101, a source 102 and a drain 103.

[0043] Furthermore, such as Figure 3 As shown, the drift correction component 400 is electrically connected to the field-effect transistor 100, and one end of the drift correction component 400 can be connected to the voltage signal input terminal 200 to apply a voltage to the drift correction component 400. The voltage signal input terminal 200 is a voltage applied to the pixel driving circuit from outside the pixel driving circuit.

[0044] Furthermore, the field-effect transistor 100 is also electrically connected to the voltage signal input terminal 200, and the voltage is applied to the gate 101 of the field-effect transistor 100 as the gate voltage.

[0045] Based on this, the drift correction component 400 is connected in parallel with the field-effect transistor 100. It can be seen that the voltage applied to the drift correction component 400 is the same as the voltage applied to the field-effect transistor 100.

[0046] The drift correction component 400 can create a voltage difference between its two ends, and the voltage difference can specifically be a drift correction such that one end connected to the voltage input signal is higher than the other end.

[0047] Based on this, the drift correction component 400 can be a diode, or a capacitor or other electronic components that can form a potential difference between the gate 101 and the source 102.

[0048] In this embodiment, since a diode has unidirectional conduction capability compared to a capacitor, and there is no time delay when controlling the switching on and off, a diode is used as a specific example of the drift correction component 400 to correct the negative drift that occurs in the threshold voltage. In this embodiment, a PN junction (hole-electron semiconductor) is provided in the diode to achieve the unidirectional conduction capability as described above.

[0049] The drift correction component 400 may be a diode containing a PN junction. In some other embodiments, multiple diodes, i.e. multiple PN junctions, may be provided, wherein each PN junction is connected in parallel so that each PN junction is connected in parallel with the field-effect transistor 100.

[0050] In this embodiment, the field-effect transistor 100 may be a MOSFET (metal-oxide-semiconductor field-effect transistor), a MODFET (modulation-doped field-effect transistor), or a MESFET (metal-semiconductor field-effect transistor).

[0051] In this embodiment, a MOSFET is used as a specific example of a field-effect transistor 100. The MOSFET can control the conduction and disconnection between the source 102 and the drain 103 according to the relationship between the gate voltage applied to the gate 101 and the threshold voltage.

[0052] The threshold voltage is a characteristic inherent to the MOSFET. When the relationship between the gate voltage and the threshold voltage changes, the on / off state between the source 102 and the drain 103 also changes.

[0053] Furthermore, with Figure 3 As a specific example, the drift correction component 400 shown includes a diode having a PN junction. When the voltage signal input terminal 200 applies a voltage equal to the gate voltage to one end of the PN junction, the PN junction can be turned on when the applied gate voltage is large enough, and a voltage difference appears across the PN junction.

[0054] Specifically, in this embodiment, it can be assumed that after the voltage passes through the PN junction, the voltage at the other end of the PN junction decreases.

[0055] Furthermore, since the PN junction is connected in parallel with the MOSFET, when a voltage difference occurs across the PN junction, a voltage difference can also be generated between the gate 101 and the source 102 of the MOSFET, which is the gate-source voltage difference.

[0056] Furthermore, when there is a gate-source voltage difference between the gate 101 and the source 102, an electric field can be generated in the IGZO of the MOSFET. The direction of the electric field is perpendicular to the IGZO and points to the substrate of the MOSFET. The substrate of the MOSFET can be a P-type substrate forming a P-type channel or an N-type substrate forming an N-type channel.

[0057] Based on this, the electric field can repel holes and attract electrons.

[0058] It can be seen that when the gate-source voltage difference remains greater than 0, the threshold voltage of the MOSFET can be maintained at greater than 0.

[0059] In some other embodiments, other boost electronic components may be used instead of diodes as drift correction components 400 to increase the voltage from gate 101 to source 102 to correct positive drift in the threshold voltage of the MOSFET.

[0060] In another embodiment of this application, such as Figure 4 As shown, the hole-electron semiconductor 300 includes:

[0061] Hole region and electron region; the hole region 301 is electrically connected to the gate 101, and the electron region 302 is electrically connected to the source 102;

[0062] The diode is configured to conduct when the gate-source voltage difference reaches a preset forward voltage difference. In this embodiment, as... Figure 4 As shown, each PN junction 300 includes a hole region 301 (P-type semiconductor) and an electron region 302 (N-type semiconductor), and still uses a MOSFET as a specific example of a field-effect transistor 100.

[0063] It can be seen that the hole region 301 is electrically connected to one end of the field-effect transistor 100, while the electron region 302 is electrically connected to the other end of the field-effect transistor 100.

[0064] Specifically, the hole region 301 is electrically connected to the gate 101 of the MOSFET, while the electron region 302 is electrically connected to the source 102 of the MOSFET.

[0065] exist Figure 4 The PN junction 300 shown also includes an empty charge region 303.

[0066] Specifically, when the hole region 301 and the electron region 302 are combined, due to the difference in carrier concentration at the interface, electrons and holes diffuse from the area with high concentration to the area with low concentration.

[0067] However, since both electrons and holes are charged, their diffusion disrupts the original electrically neutral conditions in the hole region 301 and the electron region 302.

[0068] The hole region 301 loses holes and leaves behind immobile negative ions, while the electron region 302 loses electrons and leaves behind immobile positive ions. These immobile charged particles are usually called space charges. They are concentrated near the interface between the hole region 301 and the electron region 302, forming a very thin space charge region.

[0069] Based on this, the PN junction 300 has unidirectional conductivity. If an applied voltage makes the potential of the hole region 301 higher than that of the electron region 302, when the applied voltage is large enough, the current flows from the hole region 301 to the electron region 302, and the PN junction 300 becomes low-resistance, that is, the PN junction 300 is turned on. The applied voltage is regarded as a positive voltage, and the voltage required to turn on the PN junction 300 is taken as the on-state voltage difference of the PN junction 300.

[0070] Furthermore, if the applied voltage causes the potential of the hole region 301 to be lower than the potential of the electron region 302, the current cannot flow, the PN junction 300 exhibits high resistance, that is, the PN junction 300 is not turned on, and the applied voltage is regarded as a reverse voltage.

[0071] It can be seen that the on-state voltage difference of the PN junction 300 is an inherent characteristic of the PN junction 300 and is determined by the material of the PN junction 300. Therefore, the required on-state voltage difference can be selected by choosing PN junction 300 of different materials.

[0072] exist Figure 4 In the example shown, since the PN junction 300 is connected in parallel with the MOSFET, and the voltage applied by the voltage signal input terminal 200 is applied simultaneously to the hole region 301 of the PN junction 300 and the gate 101 of the MOSFET, while the electron region 302 is connected to the source of the MOSFET, the voltage difference across the PN junction 300 is equal to the gate-source voltage difference between the source and the gate 101.

[0073] Based on this, it can be assumed that when the PN junction 300 is turned on, the gate-source voltage difference is equal to the on-state voltage difference of the PN junction 300. In other words, the gate-source voltage difference between the gate 101 and the source 102 is determined by the on-state voltage difference of the PN junction 300.

[0074] Furthermore, the forward voltage difference of the PN junction 300 can be determined by the material of the PN junction.

[0075] Specifically, the material of the PN junction 300 can be, for example, silicon or germanium. The hole region 301 of the PN junction is doped with acceptor impurities, which can be trivalent elements, etc., and the electron region 302 is doped with donor impurities, which can be pentavalent elements, etc.

[0076] Furthermore, the on-state voltage difference can be set to at least 0.7V as a standard to adjust the doping ratio of the hole region 301 and the electron region 302 so that the PN junction 300 can achieve an on-state voltage difference of 0.7V.

[0077] When the voltage signal input terminal 200 applies a voltage to the gate 101 of the MOSFET, if the applied gate voltage has not reached the conduction voltage difference of the PN junction 300, then the PN junction 300 is not turned on, and it is considered that the diode is not turned on, and the source voltage is 0V.

[0078] Furthermore, when the gate voltage applied to the MOSFET by the voltage signal input terminal 200 increases to the on-state voltage difference of the PN junction 300, the PN junction 300 is turned on, and the diode is considered to be turned on. Thus, when the PN junction 300 is turned on, the gate-source voltage difference between the gate 101 and the source 102 of the MOSFET is the on-state voltage difference of the PN junction 300.

[0079] In a specific example, the forward voltage difference of PN junction 300 can be 0.7V. When the gate voltage is applied to the voltage signal input terminal 200, the gate-source voltage difference is greater than 0. The voltage difference across PN junction 300 is equal to the gate-source voltage difference at this time. Furthermore, the hole region 301 side is the positive electrode and the electron region 302 side is the negative electrode. Therefore, holes in the hole region 301 of PN junction 300 diffuse towards the electron region 302 and remain in the empty charge region 303. At the same time, electrons in the electron region 302 diffuse towards the hole region 301 and remain in the empty charge region 303.

[0080] Furthermore, when the gate voltage applied to the voltage signal input terminal 200 reaches the on-state voltage difference of PN junction 300 of 0.7V, it can be considered that the gate-source voltage difference between the gate 101 and the source 102 is 0.7V, and the hole region 301 and the electron region 302 are connected, that is, PN junction 300 is connected.

[0081] As can be seen, due to the PN junction 300, when the PN junction 300 is turned on, the gate 101 and the source 102 can always maintain a gate-source voltage difference equivalent to the turn-on voltage. In other words, the gate voltage at the gate 101 and the source voltage at the source 102 are always inconsistent.

[0082] In some other embodiments, such as Figure 5As shown, when multiple PN junctions 300 are each connected in parallel with the field-effect transistor 100, if the forward voltage difference of each PN junction 300 is inconsistent, it can be considered that when the PN junction 300 with the lowest forward voltage difference is turned on, the gate-source voltage difference is equal to the forward voltage difference of that PN junction 300.

[0083] In some other embodiments, such as Figure 6 As shown, each circuit connected in parallel with the field-effect transistor 100 may also include multiple PN junctions 300. That is, multiple PN junctions 300 connected in series may also be connected in parallel with the field-effect transistor 100 to adjust the gate-source voltage difference when multiple PN junctions 300 connected in series are turned on.

[0084] In another embodiment of this application, the field-effect transistor circuit is configured to control the source 102 and the drain 103 to conduct when the gate voltage is greater than the threshold voltage; and to control the source 102 and the drain 103 to be cut off when the gate voltage is less than or equal to the threshold voltage.

[0085] In this embodiment, with Figure 4 Taking the pixel driving circuit shown as an example, and still using MOSFET as a specific example of field-effect transistor 100, based on the gate voltage applied at voltage signal input terminal 200, after PN junction 300 is turned on, when the gate voltage continues to increase, the on / off state between the source 102 and drain 103 of MOSFET can be adjusted according to the relationship between the gate voltage and the threshold voltage of MOSFET.

[0086] Specifically, when the gate voltage applied to the gate 101 continues to increase, and the gate voltage does not reach the threshold voltage of the MOSFET, the source 102 and the drain 103 are not connected.

[0087] Furthermore, when the gate voltage is increased to a level greater than the threshold voltage of the MOSFET, the source 102 and the drain 103 are turned on.

[0088] In this embodiment, the on-state voltage difference of PN junction 300 is less than the threshold voltage of MOSFET. That is, when the gate voltage is applied, PN junction 300 turns on first, and then, as the gate voltage increases, the source 102 and drain 103 turn on again.

[0089] In a specific example, if the threshold voltage of the MOSFET is 2V, then when the gate voltage increases to more than 2V, the source 102 and the drain 103 will conduct.

[0090] In another embodiment of this application, the field-effect transistor is further configured as follows:

[0091] Suppressing the repulsion of holes on one side of the gate 101 to maintain the gate-source voltage difference greater than zero; and maintaining the threshold voltage greater than zero while the gate-source voltage difference is greater than zero.

[0092] In this embodiment, with Figure 4 The pixel driving circuit shown is an example, and MOSFET is still used as a specific example of field-effect transistor 100.

[0093] Based on the gate voltage applied at the voltage signal input terminal 200, after the PN junction 300 is turned on, when the gate voltage continues to increase and the source 102 and drain 103 of the MOSFET are turned on, the gate-source voltage difference between the source 102 and the gate 101 is still maintained at least equal to the on-state voltage difference, that is, the gate-source voltage difference is always greater than 0.

[0094] Furthermore, a gate-source voltage difference greater than 0 can repel holes around the gate 101, leaving only immobile electrons to form a depletion layer. At the same time, electrons in the substrate will be attracted to the surface of the substrate, so that after the IGZO is conductive, the gate-source voltage difference between the source 102 and the gate 101 can still be the same as the on-state voltage difference required to conduct the PN junction 300.

[0095] Based on this, in order to turn on the source 102 and the drain 103, a gate-source voltage difference greater than the on-state voltage difference needs to be applied to the gate 101. After the IGZO is conductord, the gate-source voltage difference will suppress the phenomenon of attracting holes and repelling electrons near the gate 101 through the above-mentioned electric field, so that the threshold voltage will remain greater than 0 in this case. That is, it is equivalent to the threshold voltage of the MOSFET being forward biased, so as to maintain the threshold voltage from having too small a negative drift.

[0096] As can be seen, since IGZO is an insulator, the gate voltage applied to the gate 101 cannot form a current. A capacitor is formed on both sides of the IGZO. The gate voltage is equivalent to charging this capacitor and forming the electric field mentioned above. As the gate voltage gradually increases, attracted by the positive voltage of the gate 101, a large number of electrons accumulate on the other side of this capacitor and form an N-type conductive channel from the drain 103 to the source 102. When the N-channel transistor starts to conduct, a drain current is formed. By controlling the magnitude of the gate voltage, the strength of the electric field can be changed, thereby controlling the magnitude of the drain current. Maintaining the gate-source voltage difference can keep the threshold voltage positively biased.

[0097] In this embodiment, one or more of the above-mentioned Figure 4A first GOA is formed by connecting a field-effect transistor 100 with a PN junction 300 in parallel. The first GOA is then tested for high and low temperature reliability and long-term reliability to determine the impact of high and low temperature environments on the long-term reliability of the first GOA.

[0098] At the same time, one or more of the above Figure 1 A second GOA is formed by a field-effect transistor 100 without a parallel PN junction 300, and high and low temperature reliability and long-term reliability of the second GOA are tested to determine the impact of high temperature and low temperature environments on the long-term reliability of the second GOA.

[0099] Specifically, both the first GOA and the second GOA are placed in the same high and low temperature environment, for example, in a high temperature environment of ≥85 degrees Celsius and / or in a low temperature environment of ≤-40 degrees Celsius. The first GOA is subjected to a long-term reliability test for 1200 hours, and the second GOA is subjected to a long-term reliability test for 700 hours.

[0100] Based on this, any number of field-effect transistors 100 connected in parallel with PN junctions 300 in the first GOA can be selected, and any number of field-effect transistors 100 not connected in parallel with PN junctions 300 in the second GOA can be selected to draw the diagram as follows. Figure 7 The characteristic diagram shown.

[0101] Furthermore, Figure 7 The changes of the field-effect transistor 100 in the first GOA and the second GOA with respect to the threshold voltage are shown before and after the long-term dependence test.

[0102] The horizontal axis represents the threshold voltage when the source 102 and drain 103 are turned on, and the vertical axis represents the drain current, that is, the circuit between the drain 103 and the source 102 when it is turned on. Each curve represents the characteristic curve of a single field-effect transistor 100.

[0103] Furthermore, the following table of field-effect transistor characteristics specifically lists... Figure 7 The values ​​of the middle section of the curves represent the test results for a portion of the MOSFETs:

[0104] Table 1. Characteristics of Field-Effect Transistors

[0105]

[0106] The initial stage corresponds to Figure 7The curves marked with the word "initial" show the drain current and threshold voltage of the second GOA during the initial period of a 700-hour long-term reliability test. The second GOA 700-hour test indicates the specific values ​​of drain current and threshold voltage after a 700-hour long-term reliability test using the same second GOA as the initial stage. The first GOA 1200-hour test indicates the specific values ​​of drain current and threshold voltage after a 1200-hour long-term reliability test using the first GOA. Except for one or more field-effect transistors 100 connected in parallel with the PN junction 300, the circuit structure and connections of the first GOA and the second GOA are the same.

[0107] It can be seen that, as Figure 7 As shown in Table 1, the initial curve indicates the initial stage of the long-term reliability test of the second GOA, in which the field-effect transistor 100 is not connected in parallel with the PN junction 300. According to the test data in the initial stage of Table 1, the threshold voltage of the field-effect transistor 100 of the second GOA is maintained near 0V and approximately between -20V and 2V.

[0108] Furthermore, such as Figure 7 As shown in Table 1, after 700 hours of long-term reliability testing on the second GOA, the threshold voltage decreased to between -20V and -40V. In other words, compared to the characteristic curve of the field-effect transistor 100 in the initial stage, the threshold voltage of the field-effect transistor 100 in the second GOA showed a negative drift of approximately -20V.

[0109] Furthermore, such as Figure 7 As shown in Table 1, after 1200 hours of long-term reliability testing on the first GOA, the threshold voltage of the field-effect transistor 100 of the first GOA remained between approximately -17V and 7V. It can be seen that, due to the addition of the parallel PN junction 300, the threshold voltage of the field-effect transistor 100 of the first GOA showed a forward bias of approximately 7V compared to the characteristic curve of the field-effect transistor 100 of the second GOA in the initial stage.

[0110] As can be seen, the pixel driving circuit of the embodiment of this application, based on the conduction characteristics between the hole region 301 and the electron region 302 of the PN junction 300, comprehensively considers the gate-source voltage difference between the gate 101 and the source 102 to connect the PN junction 300 in parallel, so that when the PN junction 300 is turned on, there is a gate-source voltage difference between the gate 101 and the source 102 that is equivalent to the on-state voltage difference, and the gate-source voltage difference is greater than 0. That is to say, the potential of the gate 101 is higher than that of the source 102 and higher than that of the drain 103, thereby maintaining the threshold voltage at a certain degree of positive bias and avoiding the phenomenon that the threshold voltage is too negatively biased.

[0111] For ease of description, the above apparatus is described in terms of its functions, divided into various modules. Of course, in implementing the embodiments of this application, the functions of each module can be implemented in one or more software and / or hardware.

[0112] Based on the same inventive concept, and corresponding to the circuits of any of the above embodiments, this application also provides a driving substrate, which includes the pixel driving circuit described in any of the above embodiments.

[0113] In this embodiment, the GOA (driving substrate) may contain any one of the following connected in parallel: Figure 4 ,or Figure 5 ,or Figure 6 The field-effect pixel driving circuit shown can also select multiple field-effect transistors 100 in GOA and connect each selected field-effect transistor 100 in parallel with a PN junction 300, or it can also connect each field-effect transistor 100 in GOA in parallel with a PN junction 300.

[0114] In this embodiment, Figure 8 As a specific example of a driving substrate, in this specific example, the GOA includes multiple field-effect transistors 100, one of which is connected in parallel with a PN junction 300, forming as shown in the figure. Figure 4 The pixel driving circuit shown.

[0115] Based on the same inventive concept, and corresponding to the circuits of any of the above embodiments, this application also provides a display device, which includes the driving substrate described in any of the above embodiments.

[0116] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of this application (including the claims) is limited to these examples; within the framework of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of the embodiments of this application as described above, which are not provided in detail for the sake of brevity.

[0117] Additionally, to simplify the description and discussion, and to avoid obscuring the embodiments of this application, the well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Furthermore, the apparatus may be shown in block diagram form to avoid obscuring the embodiments of this application, and this also takes into account the fact that the details of implementation of these block diagram apparatuses are highly dependent on the platform on which the embodiments of this application will be implemented (i.e., these details should be fully understood by those skilled in the art). While specific details (e.g., circuits) have been set forth to describe exemplary embodiments of this application, it will be apparent to those skilled in the art that the embodiments of this application can be implemented without these specific details or with variations thereof. Therefore, these descriptions should be considered illustrative rather than restrictive.

[0118] Although this application has been described in conjunction with specific embodiments thereof, many substitutions, modifications, and variations of these embodiments will be apparent to those skilled in the art from the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0119] The embodiments of this application are intended to cover all such substitutions, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of this application should be included within the protection scope of this application.

Claims

1. A pixel driving circuit, characterized in that, include: A field-effect transistor, consisting of a gate and a source; A drift correction component is electrically connected between the gate and the source. The drift correction component is configured to generate a gate-source voltage difference between the gate and the source to correct the drift of the threshold voltage of the field-effect transistor. The drift correction component includes: a diode; wherein the diode is provided with a hole-electron semiconductor; The hole-electron semiconductor includes a hole region and an electron region; the hole region is electrically connected to the gate, and the electron region is electrically connected to the source. The diode is configured to turn on when the gate-source voltage difference reaches a preset forward voltage difference; The field-effect transistor is further configured to suppress hole repulsion on the gate side of the field-effect transistor to maintain the gate-source voltage difference greater than zero; and, while the gate-source voltage difference is greater than zero, to maintain the threshold voltage greater than zero to reduce the negative drift of the threshold voltage.

2. The pixel driving circuit according to claim 1, characterized in that, The field-effect transistor further includes a drain; the field-effect transistor is configured to control the source and the drain to conduct when the gate voltage applied to the gate is greater than the threshold voltage; and to control the source and the drain to be cut off when the gate voltage is less than or equal to the threshold voltage.

3. The pixel driving circuit according to claim 2, characterized in that, The field-effect transistor is further configured such that the threshold voltage is greater than the gate voltage when the diode is turned on.

4. The pixel driving circuit according to claim 1, characterized in that, The field-effect transistor includes: At least one of the following: metal-oxide-semiconductor field-effect transistor, modulation-doped field-effect transistor, and metal-semiconductor field-effect transistor.

5. The pixel driving circuit according to claim 1, characterized in that, The field-effect transistor includes: At least one of a field-effect transistor having a P-type substrate and a field-effect transistor having an N-type substrate.

6. A driving substrate, characterized in that, include: The pixel driving circuit as described in any one of claims 1 to 5.

7. A display device, characterized in that, Includes the driving substrate as described in claim 6.

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