Dual current gate regulated light emitting device and display panel

Abstract

The application discloses a double-current-gate regulated light-emitting device, and relates to the field of photoelectric display, comprising a first surface gate, a first electron transport layer, a first surface electrode layer, a second electron transport layer, a light-emitting composite layer, a second hole transport layer, a second surface electrode layer, a first hole transport layer and a second surface gate; the first surface gate and the first surface electrode layer are applied with a first bias power supply, the second surface gate and the second surface electrode layer are applied with a second bias power supply; a driving signal is applied between the first surface electrode layer and the second surface electrode layer for driving holes and electrons to recombine in the light-emitting composite layer and emit light; the first bias power supply and the second bias power supply can regulate the electron and hole migration amount in the light-emitting composite layer. The application can effectively solve the imbalance problem of the electron and hole carrier mobility in the light-emitting composite layer by increasing the current gate structure on both sides of the traditional light-emitting device, effectively improve the electron-hole light-emitting composite energy efficiency, and simultaneously optimize the light-emitting brightness and the light-emitting efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of optoelectronic display, in particular to a double current grid regulated light emitting device. BACKGROUND

[0002] Quantum dots, as a kind of cutting-edge light emitting material, with its unique properties such as extremely narrow half-width, high color purity, high quantum efficiency and wide spectral range, etc., has shown great application potential and leading trend in the field of new display technology, especially in the development of quantum dot light emitting diode (QLED).

[0003] However, although QLED technology has broad prospects, in practical application, the recombination process of charge carriers becomes a key factor restricting its luminous efficiency or brightness. In order to achieve the best device efficiency, researchers usually need to carefully design and optimize different functional layers, as well as select excellent quantum dot materials. This process not only has complex technology, but also needs to invest a lot of time, materials and human resources, which increases the research and development cost and time cycle.

[0004] More difficult is that due to the natural difference in mobility between electrons and holes, there is often an imbalance of charge carriers in the light emitting layer of QLED device. This imbalance will lead to the difficulty of achieving ideal efficiency when the free state charge carriers recombine, and further affect the light emitting performance of the whole device. This problem not only hinders the development of QLED technology, but also exists universally in organic light emitting diode (OLED) devices, which becomes a common problem restricting the further improvement of the performance of these two types of display technology.

[0005] Therefore, how to effectively improve the recombination process of charge carriers, balance the mobility of electrons and holes, and improve the luminous efficiency of QLED and OLED devices without increasing too much cost has become a key problem to be solved in the field of display technology. SUMMARY

[0006] In view of the shortcomings of the prior art, the technical problem to be solved by the present application is to provide a double current grid regulated light emitting device, which aims to solve the imbalance of charge carriers in the light emitting recombination layer in the prior art, and to realize the improvement of light emitting efficiency or light emitting brightness through current grid regulation.

[0007] To achieve the above-mentioned purpose, the present application provides a double current grid regulated light emitting device, the device structure is stacked in turn and includes: a first surface gate, a first electron transport layer, a first surface electrode layer, a second electron transport layer, a light emitting recombination layer, a second hole transport layer, a second surface electrode layer, a first hole transport layer, a second surface gate.

[0008] The first loop composed of the first face gate, the first electron transport layer and the first face electrode layer is applied with a first bias power supply; the second loop composed of the second face gate, the first hole transport layer and the second face electrode layer is applied with a second bias power supply; a driving signal is applied between the first face electrode layer and the second face electrode layer for driving holes and electrons to recombine in the light emitting recombination layer and emit light; the first bias power supply is used to regulate the electron migration amount of the electron type carrier of the light emitting recombination layer relative to the first face electrode layer, and the second bias power supply is used to regulate the hole migration amount of the hole type carrier of the light emitting recombination layer relative to the second face electrode layer, so as to improve the light emitting efficiency of hole-electron recombination.

[0009] The first bias power supply and the second bias power supply are configured to increase the carrier migration amount of the electron type carrier or the hole type carrier with smaller intrinsic mobility and to reduce the carrier migration amount of the hole type carrier or the electron type carrier with larger intrinsic mobility. The intrinsic mobility is the mobility corresponding to the electron type carrier or the hole type carrier respectively without the first bias power supply and the second bias power supply.

[0010] In the technical solution, by arranging current gates on both sides of the device and driving the gates with current, the imbalance of electron and hole carrier mobility in the light emitting recombination layer can be effectively solved. The charge dynamics in the light emitting recombination layer are regulated by the double gates, the electron-hole light emitting recombination efficiency between the first face gate and the second face gate is effectively improved, and the light emitting brightness and the light emitting efficiency can be optimized at the same time. Meanwhile, the shielding effect of the conductive electrode layer is smaller.

[0011] In a specific embodiment, the first bias power supply and the second bias power supply are voltage sources, and the first loop and the second loop further have first current limiting resistors and second current limiting resistors connected in series respectively.

[0012] The technical solution can limit the current between the face gate and the face electrode layer. The first current limiting resistor and the second current limiting resistor are used to control the current of the first loop and the second loop, so as to avoid excessive inter-electrode current and burn out the device.

[0013] In a specific embodiment, the first bias power supply and the second bias power supply include a direct current power supply, an energy storage capacitor and high and low potential nodes.

[0014] In an embodiment, when the intrinsic mobility of the electron-type carriers in the light-emitting composite layer is less than the intrinsic mobility of the hole-type carriers, the first bias power supply and the second bias power supply are configured to: the first face gate electrode applies a negative potential to the first face electrode layer to increase the electron-type carrier mobility, and the second face gate electrode applies a negative potential to the second face electrode layer to decrease the hole-type carrier mobility, so as to improve the light-emitting efficiency of hole-electron recombination.

[0015] In the technical solution, according to the difference between the intrinsic mobility of the electron carriers and the intrinsic mobility of the hole carriers, the electron injection amount is increased by applying a negative potential to the corresponding gate electrode, and the hole injection amount is decreased by applying a negative potential to the corresponding gate electrode, so as to improve the light-emitting efficiency of hole-electron recombination under the condition that holes are majority carriers.

[0016] In an embodiment, when the intrinsic mobility of the electron-type carriers in the light-emitting composite layer is greater than the intrinsic mobility of the hole-type carriers, the first bias power supply and the second bias power supply are configured to: the first face gate electrode applies a positive potential to the first face electrode layer to decrease the electron-type carrier mobility, and the second face gate electrode applies a positive potential to the second face electrode layer to increase the hole-type carrier mobility, so as to improve the light-emitting efficiency of hole-electron recombination.

[0017] In the technical solution, according to the difference between the intrinsic mobility of the electron carriers and the intrinsic mobility of the hole carriers, the electron injection amount is decreased by applying a positive potential to the corresponding gate electrode, and the hole injection amount is increased by applying a positive potential to the corresponding gate electrode, so as to improve the light-emitting efficiency of hole-electron recombination under the condition that electrons are majority carriers.

[0018] In an embodiment, the light-emitting device is an LED, an OLED or a QLED; when the light-emitting device is the OLED, a first electron injection layer is further included between the first face gate electrode and the first electron transport layer, and a first hole injection layer is further included between the second face gate electrode and the first hole transport layer.

[0019] In the technical solution, the carrier transport performance of the OLED is optimized by setting the injection layer.

[0020] In an embodiment, the first face electrode layer and the second face electrode layer are transparent conductive electrodes, at least one of the first face gate electrode and the second face gate electrode is a transparent conductive electrode, and the first face gate electrode or the second face gate electrode corresponding to the light-emitting side of the light-emitting device structure is a transparent conductive electrode.

[0021] In one embodiment, after the first bias power supply and the second bias power supply are regulated, the majority carrier mobility is reduced, the minority carrier mobility is increased, the electrons and holes in the light-emitting layer are balanced, and the light-emitting efficiency is optimized.

[0022] In one embodiment, the first bias power supply and the second bias power supply are current sources, the current of the first bias power supply is the same as that of the second bias power supply, the electron mobility of the first electron transport layer is equal to the hole mobility of the first hole transport layer, and after the first bias power supply and the second bias power supply are regulated, the electrons and holes in the light-emitting layer are balanced, and the light-emitting efficiency is optimized.

[0023] In a second aspect of the present application, a display panel based on current grid light-emitting regulation is provided, and the panel comprises:

[0024] A panel array composed of a double-current grid light-emitting device provided by the first aspect of the present application as a unit.

[0025] The present application has the following advantages: 1) By arranging current grids on both sides of the device and driving the grids with current, the unbalanced problem of electron and hole carrier mobility in the light-emitting layer can be effectively solved, the charge dynamics in the light-emitting layer can be regulated by the double grids, the electron-hole light-emitting recombination energy efficiency between the first grid and the second grid can be effectively improved, and the light-emitting brightness and light-emitting efficiency can be optimized at the same time. Meanwhile, the shielding effect of the conductive electrode layer is smaller. 2) Compared with the voltage regulation grid, the current grid has a faster response speed, a smaller shielding effect of the conductive electrode layer, and better penetration of the carrier to the light-emitting layer. 3) By regulating the double current grids, the electron and hole mobility can be adjusted to be flat, and the optimal light-emitting efficiency can be balanced. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 is a schematic diagram of a double-current grid light-emitting device in one embodiment of the present application;

[0027] Figure 2 is a schematic diagram of a double-current grid light-emitting device in one embodiment of the present application, in which the majority carrier is a hole;

[0028] Figure 3 is a schematic diagram of a double-current grid light-emitting device in one embodiment of the present application, in which the majority carrier is an electron. DETAILED DESCRIPTION

[0029] Embodiments of the present patent are described below in detail with reference to the accompanying drawings, wherein the same or similar elements or elements having the same or similar functions are denoted by the same or similar reference signs throughout the drawings. The embodiments described below by reference to the drawings are exemplary only, and are intended to explain the present patent, but cannot be understood as a limitation on the present patent.

[0030] In the description of the present patent, it should be understood that the terms "center", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present patent and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present patent.

[0031] In the description of the present patent, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "setting" should be understood broadly, for example, it can be fixedly connected, set, or detachably connected, set, or integrally connected, set. For those skilled in the art, the specific meaning of the above terms in the present patent can be understood according to the specific circumstances.

[0032] The embodiment of the present application provides a double-current grid regulated light-emitting device, as shown in the figure, the structure of the light-emitting device is sequentially stacked, including: a first surface gate 101, a first electron transport layer 102, a first surface electrode layer 103, a second electron transport layer 104, a light-emitting composite layer 105, a second hole transport layer 106, a second surface electrode layer 107, a first hole transport layer 108, and a second surface gate 109. Figure 1

[0033] The first loop composed of the first surface gate 101, the first electron transport layer 102 and the first surface electrode layer 103 is applied with a first bias power supply 110; the second loop composed of the second surface gate 109, the first hole transport layer 108 and the second surface electrode layer 107 is applied with a second bias power supply 111; the driving signal 112 is applied between the first surface electrode layer 103 and the second surface electrode layer 107 for driving the hole-electron to recombine in the light-emitting composite layer 105 and emit light; the first bias power supply is used to regulate the electron migration amount of the electron-type carrier of the light-emitting composite layer 105 relative to the first surface electrode layer 103, and the second bias power supply is used to regulate the hole migration amount of the hole-type carrier of the light-emitting composite layer 105 relative to the second surface electrode layer 107, so as to improve the light-emitting efficiency of hole-electron recombination;

[0034] ​The first bias power supply and the second bias power supply are configured to increase the carrier mobility of the electronic carrier or the hole carrier with small intrinsic mobility and to reduce the carrier mobility of the hole carrier or the electronic carrier with large intrinsic mobility; the intrinsic mobility is the mobility of the electronic carrier or the hole carrier without the first bias power supply 110 and the second bias power supply 111.

[0035] The application can effectively solve the imbalance of electron and hole carrier mobility in the light emitting layer 105 by arranging current grids on both sides of the device and driving the grids with current, and the electron mobility and the hole mobility in the light emitting layer 105 are regulated by the double grids, so that the light emitting efficiency is improved.

[0036] Typically, in the embodiment, the first bias power supply 110 and the second bias power supply 111 are voltage sources, and the first loop and the second loop further have first current limiting resistors and second current limiting resistors connected in series, respectively.

[0037] The first current limiting resistor and the second current limiting resistor are used to control the current of the first loop and the second loop, so as to avoid excessive current between the electrodes and burn out the device.

[0038] It is worth mentioning that the first bias power supply 110 and the second bias power supply 111 include a direct current power supply, an energy storage capacitor and a high-low potential node.

[0039] In the embodiment, the first bias power supply 110 and the second bias power supply 111 can be current sources or voltage sources; for the current source, the control of the bias current is more stable than that of the voltage source, and the carrier mobility can be more stably regulated.

[0040] It is worth mentioning that in the embodiment, the light emitting device can be but is not limited to LED, OLED or QLED; when the light emitting device is the OLED, a first electron injection layer is further included between the first face grid 101 and the first electron transport layer 102, and a first hole injection layer is further included between the second face grid 109 and the first hole transport layer 108.

[0041] Further, the related film layers of the embodiment can be transparent for easy display; typically, the first face electrode layer 103 and the second face electrode layer 107 are transparent conductive electrodes, at least one of the first face grid 101 and the second face grid 109 is a transparent conductive electrode, and the first face grid 101 or the second face grid 109 corresponding to the light emitting side of the light emitting device structure is a transparent conductive electrode.

[0042] It is worth mentioning that, for the present embodiment, according to the magnitude relation of the intrinsic mobility of the electron-type carriers and the intrinsic mobility of the hole-type carriers in the light-emitting recombination layer 105 (from the semiconductor, the two are difficult to balance, so the case of equal is not considered), it can be divided into the following two cases:

[0043] As shown in Figure 2 When the intrinsic mobility of the electron-type carriers in the light-emitting recombination layer 105 is less than the intrinsic mobility of the hole-type carriers, the first bias power supply 110, the second bias power supply 111 are configured to: the first face gate 101 applies a negative phase potential to the first face electrode layer 103 to increase the electron-type carrier migration amount, the second face gate 109 applies a negative phase potential to the second face electrode layer 107 to reduce the hole-type carrier migration amount, so as to improve the light-emitting efficiency of hole-electron recombination.

[0044] As shown in Figure 3 When the intrinsic mobility of the electron-type carriers in the light-emitting recombination layer 105 is greater than the intrinsic mobility of the hole-type carriers, the first bias power supply 110, the second bias power supply 111 are configured to: the first face gate 101 applies a positive phase potential to the first face electrode layer 103 to reduce the electron-type carrier migration amount, the second face gate 109 applies a positive phase potential to the second face electrode layer 107 to increase the hole-type carrier migration amount, so as to improve the light-emitting efficiency of hole-electron recombination.

[0045] Preferably, after being regulated by the first bias power supply 110 and the second bias power supply 111, the majority carrier migration amount is reduced, the minority carrier migration rate is increased, and the free electrons and holes in the light-emitting recombination layer 105 tend to be balanced, so that the light-emitting efficiency is optimized.

[0046] Preferably, the gate can be regulated by a current source; the first bias power supply 110 and the second bias power supply 111 are current sources and the currents of the first bias power supply 110 and the second bias power supply 111 are the same, the electron mobility of the first electron transport layer 102 and the hole mobility of the first hole transport layer 108 tend to be equal; after being regulated by the first bias power supply 110 and the second bias power supply 111, the free electrons and holes in the light-emitting recombination layer 105 tend to be balanced, so that the light-emitting efficiency is optimized.

[0047] In the second embodiment of the present application, a display panel based on current gate light-emitting regulation is provided, the panel comprising:

[0048] The panel array composed of the double-current gate light-emitting device regulated by the first embodiment as a unit.

[0049] The preferred embodiments of the application have been described above in detail. It should be understood that modifications and variations to the preferred embodiments could be made by those skilled in the art in light of the teachings above. It is therefore contemplated that the application can encompass other variations and modifications that fall within the scope of the claims.

Claims

1. A dual-current-gate modulated light-emitting device, characterized in that, The structure of the light-emitting device is stacked in sequence as follows: a first gate, a first electron transport layer, a first electrode layer, a second electron transport layer, a light-emitting composite layer, a second hole transport layer, a second electrode layer, a first hole transport layer, and a second gate; A first bias power supply is applied to the first circuit formed by the first gate, the first electron transport layer, and the first electrode layer; a second bias power supply is applied to the second circuit formed by the second gate, the first hole transport layer, and the second electrode layer; a driving signal is applied between the first electrode layer and the second electrode layer to drive hole-electron recombination in the light-emitting recombination layer and emit light; the first bias power supply is used to regulate the electron migration of electron carriers in the first electrode layer relative to the light-emitting recombination layer, and the second bias power supply is used to regulate the hole migration of hole carriers in the second electrode layer relative to the light-emitting recombination layer, so as to improve the luminescence efficiency of hole-electron recombination; The first bias power supply and the second bias power supply are configured to increase the carrier mobility of the electron carriers or hole carriers with lower intrinsic mobility, and decrease the carrier mobility of the hole carriers or electron carriers with higher intrinsic mobility; the intrinsic mobility is the mobility of the electron carriers and the hole carriers respectively when the first bias power supply and the second bias power supply are not applied.

2. The dual-current-gate modulated light-emitting device as described in claim 1, characterized in that, The first bias power supply and the second bias power supply are voltage sources, and the first circuit and the second circuit are respectively connected in series with a first current-limiting resistor and a second current-limiting resistor.

3. The dual-current-gate modulated light-emitting device as described in claim 1, characterized in that, The first bias power supply and the second bias power supply include: a DC power supply, an energy storage capacitor, and high and low potential nodes.

4. The dual-current-gate modulated light-emitting device as described in claim 1, characterized in that, When the intrinsic mobility of the electron carriers in the light-emitting recombination layer is less than the intrinsic mobility of the hole carriers, the first bias power supply and the second bias power supply are configured such that: the first gate electrode applies a negative phase potential relative to the first electrode layer to increase the electron carrier mobility, and the second gate electrode applies a negative phase potential relative to the second electrode layer to decrease the hole carrier mobility, thereby improving the luminous efficiency of hole-electron recombination.

5. A dual-current-gate modulated light-emitting device as described in claim 1, characterized in that, When the intrinsic mobility of the electron carriers in the light-emitting recombination layer is greater than the intrinsic mobility of the hole carriers, the first bias power supply and the second bias power supply are configured such that: the first gate applies a positive phase potential relative to the first electrode layer to reduce the migration of electron carriers, and the second gate applies a positive phase potential relative to the second electrode layer to increase the migration of hole carriers, thereby improving the luminous efficiency of hole-electron recombination.

6. A dual-current-gate modulated light-emitting device as described in claim 1, characterized in that, The light-emitting device is an LED, OLED, or QLED; wherein, when the light-emitting device is an OLED, a first electron injection layer is further included between the first gate and the first electron transport layer, and a first hole injection layer is further included between the second gate and the first hole transport layer.

7. A dual-current-gate modulated light-emitting device as described in claim 1, characterized in that, The first surface electrode layer and the second surface electrode layer are transparent conductive electrodes, and at least one of the first surface gate and the second surface gate is a transparent conductive electrode. Furthermore, the first surface gate or the second surface gate corresponding to the light-emitting side of the light-emitting device structure is a transparent conductive electrode.

8. A dual-current-gate modulated light-emitting device as described in claim 4 or 5, characterized in that, After being regulated by the first bias power supply and the second bias power supply, the majority carrier mobility decreases and the minority carrier mobility increases. The free electrons and holes in the luminescent composite layer tend to be in equilibrium, with the luminescence efficiency reaching its optimal level.

9. A dual-current-gate modulated light-emitting device as described in claim 1, characterized in that, The first bias power supply and the second bias power supply are current sources, and the current of the first bias power supply and the second bias power supply are the same. The electron mobility of the first electron transport layer and the hole mobility of the first hole transport layer tend to be equal. After being regulated by the first bias power supply and the second bias power supply, the free electrons and holes in the light-emitting composite layer tend to be balanced, with the luminous efficiency reaching the optimal level.

10. A display panel based on current-grid light emission control, characterized in that, The panel includes: A panel array composed of a dual current gate controlled light-emitting device as described in any one of claims 1-9 as a unit.

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