Display module and display device

Abstract

The invention discloses a display module and a display device. The display module comprises a display substrate, and the display substrate comprises a display area and a peripheral area surrounding the display area. The display area comprises a plurality of light-emitting elements made of organic semiconductor materials; the peripheral region includes a magnetic coil surrounding the plurality of light-emitting elements and arranged to provide a magnetic field to the plurality of light-emitting elements to increase the number of singlet excitons in the organic semiconductor material.

Description

Technical Field

[0001] This document relates to, but is not limited to, the field of display technology, and particularly relates to a display module and a display device. Background Art

[0002] An organic light-emitting diode (OLED) is an active light-emitting display device, which has the advantages of self-luminescence, wide viewing angle, high contrast ratio, low power consumption, extremely high response speed, etc. With the continuous development of display technology, a display device using an OLED as a light-emitting element and controlled by a thin film transistor (TFT) has become the mainstream product in the current display field.

[0003] However, there is a problem of low luminous efficiency in a display substrate using an organic semiconductor material as a light-emitting element. Summary of the Invention

[0004] The following is an overview of the subject matter described in detail in this document. This overview is not intended to limit the scope of protection of the claims.

[0005] Embodiments of the present disclosure provide a display module and a display device to solve the problem of low luminous efficiency in a display substrate using an organic semiconductor material as a light-emitting element.

[0006] In a first aspect, embodiments of the present disclosure provide a display module, including a display substrate, where the display substrate includes a display area and a peripheral area surrounding the display area; the display area includes a plurality of light-emitting elements of an organic semiconductor material; the peripheral area includes a magnetic coil, and the magnetic coil surrounds the plurality of light-emitting elements and is configured to provide a magnetic field to the plurality of light-emitting elements to increase the number of singlet excitons in the organic semiconductor material.

[0007] In an exemplary embodiment, it further includes an integrated circuit, which is bonded and connected to the display substrate in the peripheral area; the integrated circuit is electrically connected to the magnetic coil and is configured to provide a control signal to the magnetic coil to control the magnetic coil to generate a magnetic field with a corresponding intensity.

[0008] In an exemplary embodiment, the control signal is a current signal.

[0009] In an exemplary embodiment, the magnetic field intensity generated by the magnetic coil is less than or equal to 50 mT.

[0010] In an exemplary embodiment, the material of the magnetic coil includes a magnetic metal-organic framework composite material.

[0011] In an exemplary embodiment, the material of the magnetic coil includes CoFe2O4@UiO-66 or NiFe2O4@UiO-66.

[0012] In an exemplary embodiment, the plurality of light-emitting elements of the display substrate include red light-emitting elements, green light-emitting elements, and blue light-emitting elements; the driving voltage of the red light-emitting elements is less than the driving voltage of the green light-emitting elements, and the driving voltage of the green light-emitting elements is less than the driving voltage of the blue light-emitting elements.

[0013] In an exemplary embodiment, the integrated circuit is further configured to provide driving signals to the plurality of light-emitting elements to drive the light-emitting elements to emit light; the control signal is configured to cooperate with the timing of the driving signals so that the magnetic coil generates a magnetic field at least during the light-emitting stage of the light-emitting elements.

[0014] In an exemplary embodiment, the light-emitting element is an organic light-emitting diode.

[0015] In a second aspect, an embodiment of the present disclosure provides a display device, including the display module as described above.

[0016] The display substrate provided by the embodiment of the present disclosure solves the problem of low luminous efficiency of the display substrate using an organic semiconductor material as a light-emitting element. By arranging a magnetic coil around the light-emitting elements in the display area on the display substrate, the number of singlet excitons in the organic semiconductor light-emitting element is increased by using the magnetic field of the magnetic coil, the proportion of singlet excitons is increased, the exciton utilization rate of the OLED is greatly improved, the light extraction efficiency of the OLED can be improved, and the display effect can be enhanced.

[0017] Other features and advantages of the present application will be described in the subsequent specification, and, in part, will be obvious from the specification, or will be understood by implementing the present application. Other advantages of the present application can be realized and obtained through the solutions described in the specification and the drawings.

[0018] Other aspects can be understood after reading and understanding the drawings and the detailed description. Description of the Drawings

[0019] The drawings are used to provide an understanding of the technical solutions of the present application, and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solutions of the present application, and do not constitute a limitation to the technical solutions of the present application.

[0020] Figure 1 It is a schematic structural diagram of a display device;

[0021] Figure 2 It is a schematic plan view of a display substrate;

[0022] Figure 3 It is a schematic diagram of the equivalent circuit of a pixel driving circuit;

[0023] Figure 4 It is a schematic diagram of the structure of a display substrate in an exemplary embodiment;

[0024] Figure 5 It is a schematic diagram of the structure of a display module in an exemplary embodiment;

[0025] Figure 6 It is a cross-sectional view of the display substrate in the display area in an exemplary embodiment. Detailed implementation manners

[0026] The present disclosure describes multiple embodiments, but the description is exemplary rather than restrictive, and it will be obvious to those of ordinary skill in the art that there can be more embodiments and implementation solutions within the scope of the embodiments described in the present disclosure. Although many possible feature combinations are shown in the drawings and discussed in the detailed implementation manners, many other combination ways of the disclosed features are also possible. Unless specifically restricted, any feature or element of any embodiment can be combined with any other feature or element in any other embodiment, or can replace any other feature or element in any other embodiment.

[0027] The present disclosure includes and contemplates combinations with features and elements known to those of ordinary skill in the art. The disclosed embodiments, features, and elements of the present disclosure can also be combined with any conventional features or elements to form unique inventive solutions defined by the claims. Any feature or element of any embodiment can also be combined with features or elements from other inventive solutions to form another unique inventive solution defined by the claims. Therefore, it should be understood that any feature shown and / or discussed in the present disclosure can be implemented alone or in any suitable combination. Therefore, the embodiments are not subject to other limitations except those made according to the appended claims and their equivalent replacements. In addition, various modifications and changes can be made within the scope of protection of the appended claims.

[0028] In addition, when describing representative embodiments, the specification may have presented the method and / or process as a specific sequence of steps. However, to the extent that the method or process does not depend on the specific order of the steps described herein, the method or process should not be limited to the specific order of steps described. As will be understood by those of ordinary skill in the art, other step sequences are possible. Therefore, the specific order of steps set forth in the specification should not be construed as a limitation on the claims. In addition, the claims directed to the method and / or process should not be limited to performing their steps in the order written, as those skilled in the art can readily understand that these orders can vary and still remain within the spirit and scope of the embodiments of the present disclosure.

[0029] In the drawings, sometimes for clarity, the sizes of one or more constituent elements, the thicknesses of layers, or regions are exaggerated. Therefore, one aspect of the present disclosure is not necessarily limited to such dimensions, and the shapes and sizes of one or more components in the drawings do not reflect the true proportions. In addition, the drawings schematically show ideal examples, and one aspect of the present disclosure is not limited to the shapes or values shown in the drawings, etc.

[0030] The ordinal numbers such as "first", "second", "third", etc. in this specification are provided to avoid confusion of constituent elements, rather than to limit in terms of quantity. "Plurality" in the present disclosure means two or more quantities.

[0031] In this specification, for convenience, terms indicating orientation or positional relationships such as "middle", "upper", "lower", "front", "rear", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are used to describe the positional relationships of constituent elements with reference to the drawings, and are only for facilitating the description of this specification and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation on the present disclosure. The positional relationships of the constituent elements are appropriately changed according to the directions of the described constituent elements. Therefore, it is not limited to the terms described in the specification, and can be appropriately replaced according to the circumstances.

[0032] In this specification, unless otherwise clearly defined and limited, the terms "mounted", "connected", and "coupled" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate member, or the communication inside two elements. For those of ordinary skill in the art, the meanings of the above terms in the present disclosure can be understood according to the circumstances.

[0033] In this specification, "electrically connected" includes a case where constituent elements are connected together by an element having some electrical effect. The "element having some electrical effect" is not particularly limited as long as it can transmit an electrical signal between the constituent elements to be connected. Examples of the "element having some electrical effect" include not only electrodes and wirings, but also switching elements such as transistors, resistors, inductors, capacitors, and other elements having various functions, etc.

[0034] In this specification, "parallel" means a state where the angle formed by two straight lines is -10° or more and 10° or less, and thus also includes a state where the angle is -5° or more and 5° or less. In addition, "perpendicular" means a state where the angle formed by two straight lines is 80° or more and 100° or less, and thus also includes a state where the angle is 85° or more and 95° or less.

[0035] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0036] Figure 1 It is a schematic structural diagram of a display device. As Figure 1As shown, the display device may include a timing controller, a data driver, a scan driver, a light-emitting driver, and a pixel array. The timing controller is respectively connected to the data driver, the scan driver, and the light-emitting driver. The data driver is respectively connected to a plurality of data signal lines (D1 to Dn). The scan driver is respectively connected to a plurality of scan signal lines (S1 to Sm). The light-emitting driver is respectively connected to a plurality of light-emitting signal lines (E1 to Eo). The pixel array may include a plurality of sub-pixels Pxij, where i and j may be natural numbers. At least one sub-pixel Pxij may include a circuit unit and a light-emitting element connected to the circuit unit. The circuit unit may at least include a pixel driving circuit. The pixel driving circuit is respectively connected to the scan signal line, the data signal line, and the light-emitting signal line. In an exemplary embodiment, the timing controller may provide a gray value and a control signal suitable for the specification of the data driver to the data driver, may provide a clock signal, a scan start signal, etc. suitable for the specification of the scan driver to the scan driver, and may provide a clock signal, an emission stop signal, etc. suitable for the specification of the light-emitting driver to the light-emitting driver. The data driver may use the gray value and the control signal received from the timing controller to generate data voltages to be provided to the data signal lines D1, D2, D3,..., and Dn. For example, the data driver may sample the gray value using a clock signal and apply the data voltage corresponding to the gray value to the data signal lines D1 to Dn in units of pixel rows. n may be a natural number. The scan driver may generate scan signals to be provided to the scan signal lines S1, S2, S3,..., and Sm by receiving a clock signal, a scan start signal, etc. from the timing controller. For example, the scan driver may sequentially provide scan signals having conductive level pulses to the scan signal lines S1 to Sm. For example, the scan driver may be configured in the form of a shift register and may generate scan signals in a manner of sequentially transmitting the scan start signal provided in the form of a conductive level pulse to the next-stage circuit under the control of a clock signal. m may be a natural number. The light-emitting driver may generate emission signals to be provided to the light-emitting signal lines E1, E2, E3,..., and Eo by receiving a clock signal, an emission stop signal, etc. from the timing controller. For example, the light-emitting driver may sequentially provide emission signals having cut-off level pulses to the light-emitting signal lines E1 to Eo. For example, the light-emitting driver may be configured in the form of a shift register and may generate emission signals in a manner of sequentially transmitting the emission stop signal provided in the form of a cut-off level pulse to the next-stage circuit under the control of a clock signal. o may be a natural number.

[0037] Figure 2 It is a schematic plan view of a display substrate. As Figure 2As shown, the display substrate may include a plurality of pixel units P arranged in a matrix. At least one pixel unit P may include a first sub-pixel P1 that emits light of a first color, a second sub-pixel P2 that emits light of a second color, and a third sub-pixel P3 that emits light of a third color. Each sub-pixel may include a circuit unit and a light-emitting element. The circuit unit may at least include a pixel driving circuit. The pixel driving circuit is respectively connected to a scan signal line, a data signal line, and a light-emitting signal line. The pixel driving circuit is configured to receive a data voltage transmitted by the data signal line under the control of the scan signal line and the light-emitting signal line, and output a corresponding current to the light-emitting element. The light-emitting elements in each sub-pixel are respectively connected to the pixel driving circuit of the corresponding sub-pixel, and the light-emitting element is configured to emit light of a corresponding brightness in response to the current output by the connected pixel driving circuit.

[0038] In an exemplary embodiment, the first sub-pixel P1 may be a red sub-pixel (R) that emits red light, the second sub-pixel P2 may be a blue sub-pixel (B) that emits blue light, and the third sub-pixel P3 may be a green sub-pixel (G) that emits green light. In an exemplary embodiment, the shape of the sub-pixel may be rectangular, rhombic, pentagonal, or hexagonal. The three sub-pixels may be arranged in a horizontal side-by-side, vertical side-by-side, or pyramid shape, etc. The present disclosure does not make a limitation here.

[0039] In an exemplary embodiment, the pixel unit may include four sub-pixels. For example, the four sub-pixels may include a red sub-pixel, a green sub-pixel, a blue sub-pixel, and a white sub-pixel (W) that emits white light. Another example is that the four sub-pixels may include a red sub-pixel, a blue sub-pixel, and two green sub-pixels. In an exemplary embodiment, the four sub-pixels may be arranged in a horizontal side-by-side, vertical side-by-side, square, or diamond shape, etc. The present disclosure does not make a limitation here.

[0040] Figure 3 It is an equivalent circuit schematic diagram of a pixel driving circuit. In an exemplary embodiment, the pixel driving circuit may be a 3T1C, 4T1C, 5T1C, 5T2C, 6T1C, 7T1C, or 8T1C structure. As Figure 3 shown, the pixel driving circuit may include seven transistors (a first transistor T1 to a seventh transistor T7) and one storage capacitor C. The pixel driving circuit is respectively connected to six signal lines (a data signal line D, a first scan signal line S1, a second scan signal line S2, a light-emitting signal line E, an initial signal line INIT, and a first power supply line VDD).

[0041] In an exemplary embodiment, the pixel driving circuit may include a first node N1, a second node N2, and a third node N3. Among them, the first node N1 is respectively connected to the first pole of the third transistor T3, the second pole of the fourth transistor T4, and the second pole of the fifth transistor T5. The second node N2 is respectively connected to the second pole of the first transistor, the first pole of the second transistor T2, the gate electrode of the third transistor T3, and the second end of the storage capacitor C. The third node N3 is respectively connected to the second pole of the second transistor T2, the second pole of the third transistor T3, and the first pole of the sixth transistor T6.

[0042] In an exemplary embodiment, the first end of the storage capacitor C is connected to the first power supply line VDD, and the second end of the storage capacitor C is connected to the second node N2, that is, the second end of the storage capacitor C is connected to the gate electrode of the third transistor T3.

[0043] The gate electrode of the first transistor T1 is connected to the second scan signal line S2. The first pole of the first transistor T1 is connected to the initial signal line INIT. The second pole of the first transistor is connected to the second node N2. When a conductive level scan signal is applied to the second scan signal line S2, the first transistor T1 transfers the initial voltage to the gate electrode of the third transistor T3 to initialize the charge amount of the gate electrode of the third transistor T3.

[0044] The gate electrode of the second transistor T2 is connected to the first scan signal line S1. The first pole of the second transistor T2 is connected to the second node N2. The second pole of the second transistor T2 is connected to the third node N3. When a conductive level scan signal is applied to the first scan signal line S1, the second transistor T2 connects the gate electrode of the third transistor T3 to the second pole.

[0045] The gate electrode of the third transistor T3 is connected to the second node N2, that is, the gate electrode of the third transistor T3 is connected to the second end of the storage capacitor C. The first pole of the third transistor T3 is connected to the first node N1. The second pole of the third transistor T3 is connected to the third node N3. The third transistor T3 can be called a driving transistor. The third transistor T3 determines the amount of driving current flowing between the first power supply line VDD and the second power supply line VSS according to the potential difference between its gate electrode and the first pole.

[0046] The gate electrode of the fourth transistor T4 is connected to the first scan signal line S1. The first pole of the fourth transistor T4 is connected to the data signal line D. The second pole of the fourth transistor T4 is connected to the first node N1. The fourth transistor T4 can be called a switching transistor, a scanning transistor, etc. When a conductive level scan signal is applied to the first scan signal line S1, the fourth transistor T4 inputs the data voltage of the data signal line D into the pixel driving circuit.

[0047] The gate electrode of the fifth transistor T5 is connected to the light-emitting signal line E, the first pole of the fifth transistor T5 is connected to the first power supply line VDD, and the second pole of the fifth transistor T5 is connected to the first node N1. The gate electrode of the sixth transistor T6 is connected to the light-emitting signal line E, the first pole of the sixth transistor T6 is connected to the third node N3, and the second pole of the sixth transistor T6 is connected to the first electrode of the light-emitting element EL. The fifth transistor T5 and the sixth transistor T6 may be referred to as light-emitting transistors. When a conductive-level light-emitting signal is applied to the light-emitting signal line E, the fifth transistor T5 and the sixth transistor T6 cause the light-emitting element EL to emit light by forming a drive current path between the first power supply line VDD and the second power supply line VSS.

[0048] The gate electrode of the seventh transistor T7 is connected to the second scan signal line S2, the first pole of the seventh transistor T7 is connected to the initial signal line INIT, and the second pole of the seventh transistor T7 is connected to the first electrode of the light-emitting element EL. When a conductive-level scan signal is applied to the second scan signal line S2, the seventh transistor T7 transfers an initial voltage to the first electrode of the light-emitting element EL to initialize the electric charge accumulated in the first electrode of the light-emitting element EL or release the electric charge accumulated in the first electrode of the light-emitting element EL.

[0049] In an exemplary embodiment, the light-emitting element EL may be an OLED, including a stacked first electrode, an organic light-emitting layer, and a second electrode, or may be a QLED, including a stacked first electrode, a quantum dot light-emitting layer, and a second electrode. In this embodiment, the first electrode may be an anode, and the second electrode may be a cathode. The present disclosure does not limit this.

[0050] In an exemplary embodiment, the second electrode of the light-emitting element EL is connected to the second power supply line VSS, the signal of the second power supply line VSS is a continuously provided low-level signal, and the signal of the first power supply line VDD is a continuously provided high-level signal.

[0051] In an exemplary embodiment, the first transistor T1 to the seventh transistor T7 may be P-type transistors, or may be N-type transistors. Using transistors of the same type in the pixel driving circuit can simplify the process flow, reduce the process difficulty of the display substrate, and improve the yield of the product. In some possible implementation manners, the first transistor T1 to the seventh transistor T7 may include P-type transistors and N-type transistors.

[0052] In an exemplary embodiment, the first transistor T1 to the seventh transistor T7 may be formed of low-temperature polycrystalline silicon thin-film transistors, or may be formed of oxide thin-film transistors, or may be formed of both low-temperature polycrystalline silicon thin-film transistors and oxide thin-film transistors. The active layer of the low-temperature polycrystalline silicon thin-film transistor is made of low-temperature poly-silicon (LTPS), and the active layer of the oxide thin-film transistor is made of oxide semiconductor. The low-temperature polycrystalline silicon thin-film transistor has advantages such as high mobility and fast charging, and the oxide thin-film transistor has advantages such as low leakage current. Integrating the low-temperature polycrystalline silicon thin-film transistor and the oxide thin-film transistor on a display substrate to form a low-temperature polycrystalline oxide (LTPO) display substrate can utilize the advantages of both, achieve low-frequency driving, reduce power consumption, and improve display quality.

[0053] Taking the case where all seven transistors are P-type transistors as an example, the working process of the pixel driving circuit may include:

[0054] In the first stage A1, called the reset stage, the signal of the second scan signal line S2 is a low-level signal, and the signals of the first scan signal line S1 and the emission signal line E are high-level signals. The low-level signal of the second scan signal line S2 turns on the first transistor T1 and the seventh transistor T7. The conduction of the first transistor T1 provides the initial voltage of the initial signal line INIT to the second node N2, initializes the storage capacitor C, and clears the original data voltage in the storage capacitor. The conduction of the seventh transistor T7 provides the initial voltage of the initial signal line INIT to the first electrode of the OLED, initializes (resets) the first electrode of the OLED, and clears the pre-stored voltage inside it, completing the initialization. The high-level signals of the first scan signal line S1 and the emission signal line E turn off the second transistor T2, the fourth transistor T4, the fifth transistor T5, and the sixth transistor T6, and the OLED does not emit light in this stage.

[0055] The second stage A2, called the data writing stage or the threshold compensation stage, the signal of the first scan signal line S1 is a low-level signal, the signals of the second scan signal line S2 and the light-emitting signal line E are high-level signals, and the data signal line D outputs a data voltage. In this stage, since the second end of the storage capacitor C is at a low level, the third transistor T3 is turned on. The signal of the first scan signal line S1 being a low-level signal turns on the second transistor T2 and the fourth transistor T4. The conduction of the second transistor T2 and the fourth transistor T4 causes the data voltage output by the data signal line D to be provided to the second node N2 through the first node N1, the turned-on third transistor T3, the third node N3, and the turned-on second transistor T2, and the difference between the data voltage output by the data signal line D and the threshold voltage of the third transistor T3 is charged into the storage capacitor C. The voltage of the second end (the second node N2) of the storage capacitor C is Vd - |Vth|, where Vd is the data voltage output by the data signal line D and Vth is the threshold voltage of the third transistor T3. The signal of the second scan signal line S2 being a high-level signal turns off the first transistor T1 and the seventh transistor T7. The signal of the light-emitting signal line E being a high-level signal turns off the fifth transistor T5 and the sixth transistor T6.

[0056] The third stage A3, called the light-emitting stage, the signal of the light-emitting signal line E is a low-level signal, and the signals of the first scan signal line S1 and the second scan signal line S2 are high-level signals. The signal of the light-emitting signal line E being a low-level signal turns on the fifth transistor T5 and the sixth transistor T6. Since the voltage Vd - |Vth| is written at the second end of the storage capacitor C in the previous stage, the third transistor T3 can still maintain the on state in this stage. The power supply voltage output by the first power supply line VDD provides a driving voltage to the first electrode of the OLED through the turned-on fifth transistor T5, the third transistor T3, and the sixth transistor T6 to drive the OLED to emit light.

[0057] During the driving process of the pixel driving circuit, the driving current flowing through the third transistor T3 (the driving transistor) is determined by the voltage difference between its gate electrode and the first pole. Since the voltage of the second node N2 is Vdata - |Vth|, the driving current of the third transistor T3 is:

[0058] I = K * (Vgs - Vth) 2 = K * [(Vdd - Vd + |Vth|) - Vth] 2 = K * (Vdd - Vd) 2

[0059] Wherein, I is the driving current flowing through the third transistor T3, which is also the driving current for driving the OLED. K is a constant, Vgs is the voltage difference between the gate electrode and the first electrode of the third transistor T3, Vth is the threshold voltage of the third transistor T3, Vd is the data voltage output by the data signal line D, and Vdd is the power supply voltage output by the first power supply line VDD.

[0060] The OLED display technology is applied to mobile terminals in various scenarios, such as mobile phones, tablet computers, wearable products, and in-vehicle displays. Users have higher and higher requirements for characteristics such as the brightness, contrast ratio, viewing angle display effect, power consumption, and screen-to-body ratio of display products. However, there is a problem of low luminous efficiency in the display substrate using organic semiconductor materials as light-emitting elements.

[0061] The embodiment of the present disclosure provides a display module, including a display substrate. The display substrate includes a display area and a peripheral area surrounding the display area; the display area includes a plurality of light-emitting elements made of organic semiconductor materials; the peripheral area includes a magnetic coil, and the magnetic coil surrounds the plurality of light-emitting elements and is configured to provide a magnetic field to the plurality of light-emitting elements to increase the number of singlet excitons in the organic semiconductor material.

[0062] The display module provided by the embodiment of the present disclosure, by arranging a magnetic coil surrounding the light-emitting elements in the display area on the display substrate, uses the magnetic field of the magnetic coil to increase the number of singlet excitons in the organic semiconductor light-emitting elements, increases the proportion of singlet excitons, greatly improves the exciton utilization rate of the OLED, can improve the light extraction efficiency of the OLED, and enhances the display effect.

[0063] Figure 4 It is a schematic diagram of particles contained in the light-emitting element of the display substrate in an exemplary embodiment. As Figure 4 shown, the sub-pixels of the display substrate may include light-emitting elements, and the light-emitting elements may include organic semiconductor materials, such as OLEDs. The light-emitting elements may include an anode 31, a cathode 34, and a light-emitting functional layer 33 sandwiched between the anode 31 and the cathode 34. After the light-emitting elements are powered on, there are various metastable "particles", such as holes generated near the anode 31 electrons generated near the cathode 34 Two charges of the same type can be called bipolarons 33A, an electron-hole pair can be called a polaron pair 33B, and the further recombination of the polaron pair 33B can be called an exciton 33C. Due to the long lifetime of triplet excitons, there may also be a particle pair 33D resulting from the interaction between the exciton 33C and the charge.

[0064] The light-emitting process of OLED is achieved through radiative transitions. For radiative transitions, when a molecule is in an excited state, according to whether its total molecular spin state changes compared to the ground state S0, it can be divided into fluorescence radiation and phosphorescence radiation. According to Kasha's rule, all photophysical and photochemical processes of organic molecules occur in the first excited state. According to the spin multiplicity, the first excited state is further divided into the singlet state S1 and the triplet state T1. The transition from the singlet state S1 to the ground state S0 emits fluorescence, and the lifetime is generally on the order of nanoseconds; the transition from the triplet state T1 to the ground state S0 emits phosphorescence. Generally speaking, this process is spin-forbidden and requires the introduction of heavy metal atoms to achieve. Therefore, the phosphorescence lifetime is longer than that of fluorescence, generally on the order of microseconds. Due to the ratio and spin-forbidden limitations, the exciton utilization rate of OLED is relatively low.

[0065] Research has found that the spin state of molecules is very sensitive to magnetic field changes. The Organic Magnetic Field Effects (OMFE) refer to the magnetic response phenomenon that occurs in non-magnetic organic materials. The magnetic field can change the luminescence intensity and current of the light-emitting elements of organic semiconductor materials. For example, by doping low-concentration magnetic nanoparticles in an organic polymer, the density of OLED can be controlled by a magnetic field, the brightness of the light-emitting element can be controlled without additional electrical contacts, and the efficiency of OLED can be improved. And by setting a magnetic field outside the light-emitting element, it helps to increase the luminescence intensity of the light-emitting element.

[0066] The spin of an electron is one of the intrinsic properties of an electron and is a quantum effect. Under the influence of a magnetic field, due to its spin characteristics, the electron will precess around the magnetic field, which conforms to the following formula (1):

[0067]

[0068] where ω0 represents the precession frequency, or Larmor frequency, g is the Landé factor, is the magnetic field vector sum, including the external magnetic field (Bexternal) and the internal magnetic field (Binternal). The internal magnetic field is mainly contributed by the hyperfine interaction (HFI); μ B is the Bohr magneton, is the electron spin operator.

[0069] Under the action of an external magnetic field, the relevant processes of particle spin in OLEDs are affected, which is manifested as changes in the electrical parameters of OLEDs. Microscopically, the external magnetic field affects the spin of electrons, leading to spin flips of electrons, and changing the spin mixing rate of singlet and triplet excitons. Also, due to the different dissociation and recombination rates of singlet and triplet excitons, the densities of singlet and triplet excitons in the steady state are ultimately affected, and then the emission intensities of current or EL and PL are affected. For the explanation mechanisms of the organic magnetic field effect, the current mainstream ones include hyperfine coupling, Landé g-factor effect, and triplet-triplet annihilation and other theories. The following is a brief introduction to these three theories respectively.

[0070] Hyperfine coupling (HFI) refers to the spin-spin interaction between the electron spin and the nucleus with non-zero nuclear spin adjacent to it. That is, the spin direction and spin frequency of the carrier will change randomly, and this random change enables the carrier to generate a spin flip from spin-up to spin-down. The force of HFI is very small and is easily affected by the external magnetic field. Only a small magnetic field of a few millitesla (mT) can cause a large magnetic field response, which is mainly related to the energy level degeneracy of the triplet state. Research shows that when electrons and holes are injected into the OLED device through an external voltage, under the action of the external electric field, the carriers first form electron-hole pairs, that is, polaron pairs. Polaron pairs can be divided into singlet polaron pairs (PP1) and triplet polaron pairs (PP3). In the absence of an external magnetic field, the three energy levels of PP3 are degenerate, and at this time, the ratio of singlet polaron pairs to triplet polaron pairs is about 1 to 3. When there is an external magnetic field, the electron Zeeman splitting energy ΔE cannot be ignored, that is, the triplet energy level degeneracy is lifted, the conversion channel is closed, and the ratio of S1 and T1 will also be adjusted accordingly, affecting the spin conversion between singlet and triplet states. The external magnetic field can increase the ratio of singlet excitons and decrease the ratio of triplet excitons. In other words, the external magnetic field has an inhibitory effect on both the intersystem crossing (ISC) process and the reverse intersystem crossing (RISC) process. Therefore, in devices dominated by the ISC process, the external magnetic field will enhance the device's luminescence, causing changes in constants such as the device's luminescence intensity and current density.

[0071] The Landé g-factor effect is related to the process related to exciton spin. Generally, the electrons and holes that make up the exciton have different g-factors, and there is a slight difference between them. According to formula (1), when there is an external magnetic field, because Δg≠0, then Δω0≠0, that is, the precession frequencies of the electrons and holes that make up the exciton are inconsistent. This inconsistency in the motion rate will promote the conversion between singlet and triplet states.

[0072] The triplet-triplet annihilation effect, i.e., the TTA effect, refers to the effect that two triplets collide and transform into singlets. Regarding the TTA effect, the following explanation is provided: When two T-state excitons collide, an intermediate state of (TT)i will be formed. Since there are 3 sublevels in the triplet state, there are 9 sublevels in (TT)i. Generally speaking, without an external force, among these 9 sublevels, only 3 sublevels have the properties of singlets, that is, only these 3 sublevels can produce the luminescent singlet S1, while the other sublevels either collide and quench the energy of one triplet state, and the other returns to the ground state; or they do not participate in the reaction, and the final state is the same as the initial state. When a magnetic field is applied, since the magnetic field will lift the degeneracy of the triplet energy levels, this will cause the state of each (TT)i to change accordingly. At low magnetic fields, this change will increase the number of (TT)i with singlet properties. Correspondingly, the number of luminescent singlets S will also increase, resulting in enhanced luminescence; while at high magnetic fields, these singlets (TT)i will successively lose their singlet properties, and thus the luminescence begins to weaken. However, when the magnetic field is high enough, the number of (TT)i with singlet properties will decrease to only 2. In this case, the luminescence of the device will be lower than that of the device without an external magnetic field.

[0073] The above three theories all explain the organic magneto-optic effect. Based on the above theories, the solution of the present disclosure will be further described below.

[0074] Figure 5 It is a schematic structural diagram of a display module in an exemplary embodiment. As Figure 5 shown, the display module includes a display substrate and an integrated circuit 311 bonded to the display substrate. The display substrate includes a display area 100 and a peripheral area 200 surrounding the display area 100. The display area 100 at least includes a plurality of regularly arranged sub-pixels. The plurality of sub-pixels are configured to display dynamic pictures or still images. The plurality of sub-pixels can be arranged in an array along a first direction X and a second direction Y. The first direction X and the second direction Y intersect. For example, the second direction Y can be perpendicular to the first direction X. The display area 100 can be referred to as the active area (AA). A sub-pixel can include a light-emitting element. The material of the light-emitting element can include an organic semiconductor material. For example, the light-emitting element can be an OLED. The peripheral area 200 is provided with a magnetic coil 201. The magnetic coil 201 can surround the display area 100 and is configured to provide a magnetic field to a plurality of light-emitting elements to increase the number of singlet excitons in the organic semiconductor material and increase the proportion of the number of singlet excitons in the organic semiconductor material. Due to the forbidden band limitation of the singlet and triplet radiative transitions of OLEDs, the available exciton utilization rate is limited. In this embodiment, the organic magnetic effect is utilized, and the exciton utilization rate can be improved by applying an external magnetic field, thereby improving the luminescence efficiency.

[0075] In an exemplary embodiment, the shape of the display area 100 may be quadrilateral, circular, oval, polygonal with other shapes, or irregular, etc. The corner shape of the display area 100 may be a rounded corner, and the present disclosure does not limit this. In an exemplary embodiment, the display substrate may be deformable, such as being curled, bent, folded, or rolled up.

[0076] In an exemplary embodiment, the peripheral area 200 includes a bonding area 300 located on one side of the display area 100, and the integrated circuit 311 may be bonded and connected to the display substrate in the bonding area 300. In an exemplary embodiment, the bonding area 300 may include a bending area (not shown in the figure), and the integrated circuit 311 may be bent to the backlight surface of the display substrate. The peripheral area 200 may also include a gate driving circuit (not shown in the figure), and a flexible printed circuit (FPC) may also be bonded and connected in the bonding area 300.

[0077] In an exemplary embodiment, the integrated circuit 311 may be electrically connected to the magnetic coil 201 to provide a control signal to the magnetic coil 201, so as to control the magnetic coil 201 to generate a magnetic field with a corresponding intensity. For example, the control signal may be a current signal, and the magnetic field intensity can be changed by controlling the current intensity. Figure 5 As shown, the magnetic coil 201 is located at the edge of the display substrate and can be connected to the integrated circuit 311 through traces. By adjusting the magnitude and timing of the control signal provided by the integrated circuit 311, the magnetic field formed by the magnetic coil 201 can be dynamically regulated, so as to flexibly adjust the display situation of the display substrate.

[0078] In an exemplary embodiment, the magnetic coil 201 uses a magnetic metal-organic framework (MMOFs) composite material, such as CoFe2O4@UiO-66 and NiFe2O4@UiO-66, etc. The morphology of the magnetic metal-organic framework composite material is uniform, has a high saturation magnetization intensity and specific surface area, and MMOFs have the dual advantages of metal-organic framework (MOFs) materials and magnetic materials. After receiving the control signal, the magnetic coil 201 can excite a surface plasmon (SPs) field to induce the formation of a steady magnetic field based on the local enhancement effect of surface plasmon polaritons (SPP). Using this magnetic field, the intersystem crossing between the singlet state and the triplet excited state can be enhanced, and the regulation of the exciton distribution ratio between the singlet state and the triplet excited state in the OLED can be realized. Under the action of the magnetic field, the OLED forms an organic spin valve light-emitting device, and the proportion of singlet excitons can reach up to 50%, which greatly improves the utilization rate of excitons in the OLED, can improve the light extraction efficiency of the OLED, and improves the performance of the display substrate at low gray levels.

[0079] Surface plasmons are a special electromagnetic mode existing at the metal-dielectric interface. They have the characteristics of local field enhancement and sub-wavelength confinement, and are a new type of information carrier that combines the advantages of photons and electrons. In this embodiment, the magnetic field intensity of the SPP wave is regulated by current control, and thus the exciton utilization rate of the OLED is controlled.

[0080] In an exemplary embodiment, the magnetic field intensity generated by the magnetic coil 201 can be less than or equal to 50 mT. By setting the magnetic field intensity generated by the magnetic coil 201 to be less than or equal to 50 mT, on the one hand, it is possible to avoid interference with electronic components due to excessive magnetic field intensity. On the other hand, at room temperature, since the magnetoconductance or magneto-electroluminescence in the organic semiconductor light-emitting device exhibits a low magnetic field effect of rapid increase at low magnetic fields and a high magnetic field effect of slow increase at high magnetic fields, a magnetic field intensity less than or equal to 50 mT helps to improve the response speed of sub-pixels at low gray levels.

[0081] In an exemplary embodiment, the multiple sub-pixels in the display area 100 may include red sub-pixels, green sub-pixels, and blue sub-pixels. The red sub-pixels include red light-emitting elements, the green sub-pixels include green light-emitting elements, and the blue sub-pixels include blue light-emitting elements. When the magnetic field intensity generated by the magnetic coil 201 is constant, the driving voltages of the red light-emitting element, the green light-emitting element, and the blue light-emitting element can be set to increase in sequence to cooperate with the magnetic field intensity and perform differential adjustment on light-emitting elements of different colors. By adjusting the driving voltages of the light-emitting elements to cooperate with the magnetic field intensity, differential compensation for light-emitting elements of different colors can be achieved, reducing the number of magnetic fields required to compensate light-emitting elements of different colors, avoiding interference with the device and exciton distribution, and ensuring the display effect.

[0082] With the development of technology, users increasingly value the display effect of display products at low gray levels. However, at low gray levels, display products are prone to display defects such as trailing shadows and grayscale lag.

[0083] In an exemplary embodiment, due to the different light-emitting conditions of the red light-emitting element, the green light-emitting element, and the blue light-emitting element, the driving voltages of the light-emitting elements of different colors and the magnetic field strength generated by the magnetic coil 201 can be set with emphasis to achieve better cooperation and obtain a better display effect. For example, from the perspective of reducing voltage and improving luminous efficiency, since the blue light-emitting element has a greater demand in this regard, the magnetic field strength can be set according to the driving voltage of the blue light-emitting element, so that the compensation effect of the magnetic field on the blue light-emitting element is better, thereby obtaining a more obvious improvement in the display effect; from the perspective of improving adverse effects such as gray-scale hysteresis, since the green light-emitting element has the greatest impact on the low-gray-scale brightness, the magnetic field strength can be set according to the driving voltage of the green light-emitting element, so that the compensation effect of the magnetic field on the green light-emitting element is better, thereby better improving the low-gray-scale display effect of the display substrate. Moreover, after clarifying the design direction of the compensation effect of the magnetic field, the magnetic field strength can be adjusted in combination with requirements such as the overall color ratio of the display substrate and the display uniformity to ensure the overall display effect of the display substrate. The magnetic field strength and the driving voltages of the light-emitting elements of different colors can be set according to the material of the light-emitting element and the specific requirements for the display situation.

[0084] In an exemplary embodiment, the timing of the control signal provided by the integrated circuit 311 to the magnetic coil 201 can be coordinated with the timing of the driving signal provided by the integrated circuit 311 to the light-emitting element, so that the magnetic field acts on the light-emitting stage of the light-emitting element. By using the organic magnetic field effect, the exciton utilization rate can be improved, the light-emitting element can be quickly turned on and off, the response efficiency can be improved, and low-gray-scale adverse phenomena such as trailing shadows and gray-scale hysteresis can be improved, thereby improving the display effect. Moreover, compared with the case where the integrated circuit 311 drives the light-emitting element alone, under the superposition of the magnetic field, the light-emitting brightness of the light-emitting element can be improved by using the organic magnetic field effect, which helps to improve the maximum brightness of the display module and improve the display quality.

[0085] Figure 6 FIG. is a cross-sectional view of a display substrate in a display area in an exemplary embodiment, showing the structures of three sub-pixels of the display substrate. As Figure 6 shown, in a plane perpendicular to the display substrate, the display substrate may include a driving circuit layer 12 provided on a substrate 10, a light-emitting device 13 provided on a side of the driving circuit layer 12 away from the substrate 10, and a packaging layer 14 provided on a side of the light-emitting device 13 away from the substrate 10. In some possible implementation manners, the display substrate may include other film layers, such as spacer columns, a touch layer, etc., and may also include an upper glass on a side of the packaging layer 14 away from the substrate 10, which is not limited in the present disclosure.

[0086] In some exemplary embodiments, the substrate 10 may be a flexible substrate or a rigid substrate. The flexible substrate may include a stacked first flexible material layer, a first inorganic material layer, a semiconductor layer, a second flexible material layer, and a second inorganic material layer. The materials of the first flexible material layer and the second flexible material layer may be polyimide (PI), polyethylene terephthalate (PET), or a surface-treated polymer soft film, etc. The materials of the first inorganic material layer and the second inorganic material layer may be silicon nitride (SiNx) or silicon oxide (SiOx), etc., for improving the water and oxygen resistance of the substrate. The material of the semiconductor layer may be amorphous silicon (a-Si).

[0087] In some exemplary embodiments, the driving circuit layer 12 of each sub-pixel may include a plurality of transistors and a storage capacitor that constitute a pixel driving circuit. Figure 6 Taking the example that each sub-pixel includes a driving transistor and a storage capacitor for illustration. In some possible implementation manners, the driving circuit layer 12 of each sub-pixel may include: a first insulating layer 21 disposed on the substrate; an active layer disposed on the first insulating layer 21; a second insulating layer 22 covering the active layer; a gate electrode and a first capacitor electrode disposed on the second insulating layer 202; a third insulating layer 23 covering the gate electrode and the first capacitor electrode; a second capacitor electrode disposed on the third insulating layer 23; a fourth insulating layer 24 covering the second capacitor electrode. Through holes are formed in the second insulating layer 22, the third insulating layer 23, and the fourth insulating layer 24, and the through holes expose the active layer; a source electrode and a drain electrode are disposed on the fourth insulating layer 24, and the source electrode and the drain electrode are respectively connected to the active layer through the through holes; a planarization layer 25 covering the foregoing structure, and through holes are formed in the planarization layer 25, and the through holes expose the drain electrode. The active layer, the gate electrode, the source electrode, and the drain electrode form a driving transistor 231, and the first capacitor electrode and the second capacitor electrode form a storage capacitor 232. In an exemplary embodiment, the foregoing insulating layers may be formed of an organic material or an inorganic material, and a single insulating layer may be a single-layer structure or a multi-layer composite structure, and the present disclosure does not limit this.

[0088] In some exemplary embodiments, the light-emitting device 13 may include an anode 31, a pixel defining layer 32, a light-emitting functional layer 33, and a cathode 34. The anode 31 is disposed on the planarization layer 25 and is connected to the drain electrode of the driving transistor 231 through a through hole formed in the planarization layer 25; the pixel defining layer 32 is disposed on the anode 31 and the planarization layer 25, and a pixel opening is provided on the pixel defining layer 32, and the pixel opening exposes the anode 31; the light-emitting functional layer 33 is at least partially disposed in the pixel opening, and the light-emitting functional layer 33 is connected to the anode 31; the cathode 34 is disposed on the light-emitting functional layer 33, and the cathode 34 is connected to the light-emitting functional layer 33; the light-emitting functional layer 33 emits corresponding color light under the drive of the anode 31 and the cathode 34.

[0089] In an exemplary embodiment, the material of the anode 31 may be a transparent conductive material, which may be a single material or a stack of multiple materials. For example, it may be a three-layer composite structure of ITO / Ag / ITO, and the present disclosure is not limited thereto.

[0090] In some exemplary embodiments, the encapsulation layer 14 may include a stacked first encapsulation layer 41, second encapsulation layer 42, and third encapsulation layer 43. The first encapsulation layer 41 and the third encapsulation layer 43 may be made of inorganic materials to prevent the penetration of moisture, oxygen, etc., and the second encapsulation layer 42 may be made of an organic material to improve the flatness of the encapsulation layer 14. The second encapsulation layer 42 is disposed between the first encapsulation layer 41 and the third encapsulation layer 43 to ensure that external water vapor cannot enter the light-emitting device 13. In an exemplary embodiment, the encapsulation layer 14 may cover the display area AA.

[0091] In some exemplary embodiments, the light-emitting functional layer of the light-emitting device may include a light-emitting layer (EML, Emitting Layer), and one or more of a hole injection layer (HIL, Hole Injection Layer), hole transport layer (HTL, Hole Transport Layer), hole blocking layer (HBL, Hole Block Layer), electron blocking layer (EBL, Electron Block Layer), electron injection layer (EIL, Electron Injection Layer), and electron transport layer (ETL, Electron Transport Layer). Under the voltage drive of the anode and the cathode, light is emitted according to the required gray scale by using the light-emitting characteristics of the organic material.

[0092] In an exemplary embodiment, the magnetic coil 201 may be disposed within the driving circuit layer 12, the light-emitting device 13, or the encapsulation layer 14, or the magnetic coil 201 may be disposed at other positions on the display substrate. The position of the magnetic coil 201 on the display substrate may be set as needed, and the present disclosure is not limited thereto.

[0093] In an exemplary embodiment, the magnetic coil 201 may be disposed on the same layer as the anode 31.

[0094] The embodiments of the present disclosure further provide a display device, including the display module described in any of the above embodiments. The display device may be: an OLED display, a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, or any product or component with a display function, and the embodiments of the present disclosure are not limited thereto.

[0095] Although the embodiments of the present disclosure have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A display module, comprising: A display substrate, the display substrate comprising a display area and a peripheral area surrounding the display area; The display area includes a plurality of light-emitting elements made of organic semiconductor materials; The peripheral area includes a magnetic coil, which surrounds the plurality of light-emitting elements and is configured to provide a magnetic field to the plurality of light-emitting elements to increase the number of singlet excitons in the organic semiconductor material.

2. The display module according to claim 1, characterized in that: It also includes an integrated circuit, which is bound and connected to the display substrate in the peripheral area; the integrated circuit is electrically connected to the magnetic coil and is configured to provide a control signal to the magnetic coil to control the magnetic coil to generate a magnetic field of corresponding strength.

3. The display module according to claim 2, characterized in that: The control signal is a current signal.

4. The display module according to claim 2, characterized in that: The magnetic field strength generated by the magnetic coil is less than or equal to 50 mT.

5. The display module according to claim 2, characterized in that: The material of the magnetic coil comprises a magnetic metal-organic framework composite material.

6. The display module according to claim 5, characterized in that: The material of the magnetic coil includes CoFe2O4@UiO-66 or NiFe2O4@UiO-66.

7. The display module according to claim 2, characterized in that: The multiple light-emitting elements of the display substrate include a red light-emitting element, a green light-emitting element and a blue light-emitting element; the driving voltage of the red light-emitting element is lower than the driving voltage of the green light-emitting element, and the driving voltage of the green light-emitting element is lower than the driving voltage of the blue light-emitting element.

8. The display module according to claim 2, characterized in that: The integrated circuit is further configured to provide a driving signal to the plurality of light emitting elements to drive the light emitting elements to emit light; The control signal is configured to match the timing of the drive signal so that the magnetic coil generates a magnetic field at least during the light-emitting phase of the light-emitting element.

9. The display module according to claim 2, characterized in that: The light emitting element is an organic light emitting diode.

10. A display device, comprising the display module according to any one of claims 1 to 9.

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