Unidirectional cut-off current gate regulation and control light-emitting device

Abstract

The invention, which relates to the photoelectric display field, discloses a one-way cut-off current gate regulation light-emitting device comprising an anode, a first hole transport layer, a light-emitting composite layer, a first electron transport layer, and a cathode. A first loop is formed between the anode and the cathode, a driving signal is applied between the anode and the cathode, and electrons and holes are injected into the light-emitting composite layer for composite light emitting; the device further comprises a one-way throttling current gate structure. The one-way throttling current gate structure is arranged between the cathode and the first electron transport layer or between the first hole transport layer and the anode; the one-way throttling current gate structure light-emitting composite layer participates in the electron recombination amount or the hole recombination amount, so that the light-emitting efficiency of the device is regulated and controlled, and the light-emitting efficiency of the device can be effectively improved.

Description

Technical Field

[0001] The present invention relates to the field of optoelectronic display, and in particular to a unidirectional current-cutoff current gate-regulated light-emitting device. Background Art

[0002] Due to process conditions and material properties, there are natural and difficult-to-eliminate differences in the mobility of electrons and holes, resulting in a serious imbalance of charge carriers in the light-emitting layer of QLED devices. This imbalance not only makes it difficult for free charge carriers to achieve ideal efficiency when recombinating, which in turn has a serious negative impact on the luminescence performance of the entire device, but also becomes a key bottleneck restricting the further development and performance improvement of QLED technology. This problem is also prevalent in organic light-emitting diode (OLED) devices, becoming a common problem that restricts the further improvement of the performance of these two types of display technologies.

[0003] Therefore, how to effectively improve the recombination process of charge carriers and balance the mobility of electrons and holes through innovative technical means and strategies without significantly increasing costs, thereby significantly improving the luminous efficiency and performance of QLED and OLED devices, has become a key scientific problem and technical challenge that needs to be urgently solved in the current field of display technology.

[0004] In related technologies, gate control is used to control the injection amount of electrons or holes. However, in these technologies, the control gate may cause carrier conduction or electric field shielding during current injection or built-in electric field construction, which affects the effective injection of control carriers and causes inefficient control. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the technical problem to be solved by the present invention is to provide a unidirectional throttling current gate to regulate the light-emitting device. The purpose is to solve the imbalance phenomenon of charge carriers in the light-emitting composite layer in the existing technology, and to achieve effective control of the carrier migration amount by designing a unidirectional throttling current gate. Compared with the related technology of using a gate to regulate the injection amount of electrons or holes, it is more efficient.

[0006] To achieve the above objectives, the present invention provides a unidirectional current-cutoff current gate-controlled light-emitting device, the device comprising, in order: an anode, a first hole transport layer, a light-emitting composite layer, a first electron transport layer, and a cathode; a first circuit is formed between the anode and the cathode, and a driving signal is applied thereto, and electrons and holes are injected into the light-emitting composite layer to recombine and emit light;

[0007] The device further includes a unidirectional throttling current gate structure; the unidirectional throttling current gate structure is disposed between the cathode and the first electron transport layer or between the first hole transport layer and the anode; the unidirectional throttling current gate structure is configured as follows:

[0008] When the unidirectional throttling current gate structure is arranged between the cathode and the first electron transport layer, the unidirectional throttling current gate structure includes a thin hole transport layer, a second electron transport layer and a first control electrode; the film thickness of the thin hole transport layer is less than the thickness of the first electron transport layer and / or the second electron transport layer; the thin hole transport layer is directly or through a first conductive surface layer and is electrically connected to the first electron transport layer in an adjacent stack, and the second electron transport layer is arranged between the thin hole transport layer and the cathode; the first control electrode is electrically connected to the thin hole transport layer, and forms a second loop with the second electron transport layer and the cathode to apply a first bias signal; the first bias signal is used to regulate the number of electrons conducted from the cathode to the thin hole transport layer and further conducted to the light-emitting composite layer and the amount of electrons participating in the composite, so as to regulate the luminous efficiency of the device;

[0009] When the unidirectional throttling current gate structure is arranged between the first hole transport layer and the anode, the unidirectional throttling current gate structure includes a thin electron transport layer, a second hole transport layer and a second control electrode; the film thickness of the thin electron transport layer is less than the thickness of the first hole transport layer and / or the second hole transport layer; the thin electron transport layer is directly or through a second conductive surface layer and electrically connected to the adjacent stack of the first hole transport layer, and the second hole transport layer is arranged between the thin electron transport layer and the anode; the second control electrode is electrically connected to the thin electron transport layer, and forms a third loop with the second hole transport layer and the anode to apply a second bias signal; the second bias signal is used to regulate the number of holes conducted from the anode to the thin electron transport layer and further conducted to the light-emitting composite layer and the amount of holes participating in the composite, so as to regulate the luminous efficiency of the device.

[0010] In this technical solution, on the one hand, by setting a unidirectional current cutoff gate structure, the carrier injection amount can be effectively regulated, and the injection amount of carriers participating in the recombination of the light-emitting composite layer can be effectively regulated. Based on this, the luminous efficiency can be effectively regulated and improved; on the other hand, this technical solution adopts a unidirectional current cutoff gate structure. When the carrier injection amount is controlled according to the bias signal of the unidirectional current cutoff gate structure, the carrier injection can only be injected from the cathode / anode to the first electron transport layer / first hole transport layer, that is, the carriers are blocked by the thin hole transport layer / thin electron transport layer to prevent backflow, and can accumulate on the thin hole transport layer / thin electron transport layer, which is convenient for injection into the first electron transport layer / first hole transport layer, thereby helping to improve the luminous recombination efficiency.

[0011] In a specific embodiment, the second loop is further connected in series with a first current-limiting resistor, or the third loop is further connected in series with a second current-limiting resistor.

[0012] This technical solution can limit the current of the first loop / second loop, and avoid excessive inter-electrode current and burning of the device.

[0013] In a specific embodiment, the first bias signal or the second bias signal is a current-type drive signal or a voltage-type drive signal; the voltage-type drive signal includes an adjustable DC power supply, an energy storage capacitor, or a high or low potential node.

[0014] In one embodiment, the light-emitting composite layer is an LED, an OLED, or a QLED;

[0015] Among them, when the light-emitting composite layer is the OLED, if the one-way throttling current gate structure is arranged between the cathode and the first electron transport layer, a first hole injection layer is also arranged between the first hole transport layer and the anode; when the light-emitting composite layer is the OLED, if the one-way throttling current gate structure is arranged between the first hole transport layer and the anode, a first electron injection layer is also arranged between the first electron transport layer and the cathode.

[0016] In this technical solution, the carrier transport performance of the OLED is optimized by providing an injection layer.

[0017] In a specific embodiment, the unidirectional throttling current gate structure is arranged between the cathode and the first electron transport layer, the thin hole transport layer is arranged between the first electron transport layer and the second electron transport layer, and the control electrode is arranged around the same layer of the thin hole transport layer.

[0018] Furthermore, in a specific embodiment, the control electrodes are arranged in a network-like manner on the same layer of the thin hole transport layer in a cross-arrangement.

[0019] In a specific embodiment, the unidirectional throttling current gate structure is arranged between the first hole transport layer and the anode, the thin electron transport layer is arranged between the first hole transport layer and the second hole transport layer, and the control electrode is arranged around the same layer of the thin electron transport layer.

[0020] Furthermore, in a specific embodiment, the control electrodes are arranged in a network-like manner on the same layer of the thin electron transport layer in a cross-arrangement.

[0021] In a specific embodiment, an insulating layer is further provided between the control electrode and the second hole transport layer, and an insulating layer is also provided between the control electrode and the first hole transport layer.

[0022] In a specific embodiment, the device includes a first unidirectional throttling current gate structure disposed between the cathode and the first electron transport layer and a second unidirectional throttling current gate structure disposed between the first hole transport layer and the anode.

[0023] Beneficial effects of the present invention: 1) The present invention can effectively regulate the amount of carrier injection by setting a unidirectional current cutoff current gate structure, and can effectively regulate the amount of carrier injection participating in the recombination of the light-emitting composite layer. Based on this, the luminous efficiency can be effectively regulated and improved; 2) The present invention adopts a unidirectional current cutoff current gate structure. When the amount of carrier injection is controlled according to the bias signal of the unidirectional current cutoff current gate structure, the carrier injection can only be injected from the cathode / anode to the first electron transport layer / first hole transport layer, that is, the carriers are blocked by the thin hole transport layer / thin electron transport layer to prevent backflow, and can be accumulated on the thin hole transport layer / thin electron transport layer, which is convenient for injection into the first electron transport layer / first hole transport layer, thereby helping to improve the luminous recombination efficiency. 3) Compared with the voltage control gate, the current gate of the present invention has a fast response speed, a small shielding effect of the conductive electrode layer, and the carriers can better penetrate into the light-emitting composite layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of a light-emitting device in accordance with a specific embodiment of the present invention, in which a unidirectional current-cutoff current gate is used to regulate electron carriers;

[0025] Figure 2 This is a structural schematic diagram of a light-emitting device with a unidirectional current-cutoff gate regulating electron carriers in another specific embodiment of the present invention;

[0026] Figure 3 This is a schematic structural diagram of a light-emitting device in accordance with a specific embodiment of the present invention, in which a unidirectional current-cutoff current gate is used to regulate hole carriers;

[0027] Figure 4 This is a schematic structural diagram of a light-emitting device in accordance with another specific embodiment of the present invention, wherein a unidirectional current-cutoff current gate is used to regulate hole carriers;

[0028] Figure 5 This is a schematic diagram of the principle of a light-emitting device in which a unidirectional current-cutoff current gate regulates electron carriers in a specific embodiment of the present invention;

[0029] Figure 6 This is a schematic diagram of the principle of a light-emitting device in which a unidirectional current-cutoff current gate regulates electron carriers in another specific embodiment of the present invention;

[0030] Figure 7This is a schematic diagram of the principle of a light-emitting device in which a unidirectional current-cutoff current gate regulates electron carriers in another specific embodiment of the present invention;

[0031] Figure 8 is a side view of a thin transmission layer structure in one embodiment of the present invention;

[0032] Figure 9 It is a top cross-sectional view of a thin transmission layer structure in a specific embodiment of the present invention. DETAILED DESCRIPTION

[0033] The following describes in detail embodiments of the present invention, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0034] In the description of this patent, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing this patent and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limitations on this patent.

[0035] In the description of this patent, it should be noted that, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," and "set" should be understood in a broad sense. For example, they can refer to fixed connection or set, detachable connection or set, or integral connection or set. Those skilled in the art will understand the specific meanings of the above terms in this patent based on the specific circumstances.

[0036] The embodiment of the present invention provides a unidirectional current-cutoff current gate controlled light emitting device, such as Figures 1-9 As shown, the device includes, in sequence: an anode 101, a first hole transport layer 102, a light-emitting composite layer 103, a first electron transport layer 104, and a cathode 105; a first circuit is formed between the anode 101 and the cathode 105 and a driving signal 106 is applied, and electrons and holes are injected into the light-emitting composite layer 103 to recombine and emit light;

[0037] The device also includes a unidirectional throttling current gate structure 107; the unidirectional throttling current gate structure 107 is arranged between the cathode 105 and the first electron transport layer 104 or between the first hole transport layer 102 and the anode 101; typically, the unidirectional throttling current gate structure 107 can be configured to be arranged on the anode 101 side or the cathode 105 side, or both.

[0038] Typical Scenario 1

[0039] like Figure 1 、 Figure 2 As shown, the unidirectional throttling current gate structure 107 is arranged between the cathode 105 and the first electron transport layer 104, and the unidirectional throttling current gate structure 107 includes a thin hole transport layer 108, a second electron transport layer 109 and a first regulating electrode 110; the film thickness of the thin hole transport layer 108 is less than the thickness of the first electron transport layer 104 and / or the second electron transport layer 109; the thin hole transport layer 108 is directly or through the first conductive surface layer 111 adjacent to the first electron transport layer 104 and is electrically connected. The second electron transport layer 109 is arranged between the thin hole transport layer 108 and the cathode 105; the first control electrode 110 is electrically connected to the thin hole transport layer 108, and forms a second circuit with the second electron transport layer 109 and the cathode 105 to apply a first bias signal 112; the first bias signal 112 is used to regulate the number of electrons conducted from the cathode 105 to the thin hole transport layer 108 and further conducted to the light-emitting composite layer 103 and the amount of electrons participating in the recombination, so as to regulate the luminous efficiency of the device.

[0040] In scenario 1 of this embodiment, the second loop is further connected in series with a first current-limiting resistor.

[0041] In scenario 1, the thin hole transport layer 108 is disposed between the first electron transport layer 104 and the second electron transport layer 109, and the control electrode is disposed around the same layer as the thin hole transport layer 108. Figure 8 、 Figure 9 As shown, the control electrodes are arranged in a network-like manner on the same layer of the thin hole transport layer 108 in a cross-arranged manner.

[0042] Optionally, an insulating layer is further provided between the control electrode and the second electron transport layer 109 , and an insulating layer is also provided between the control electrode and the first electron transport layer 104 .

[0043] The following is a brief description of the current gate control principle of scenario 1.

[0044] like Figure 5 、 Figure 6As shown, the control electrode applies a positive potential relative to the cathode 105, the thin hole transport layer 108 and the second electron transport layer 109 are connected, and the electrons from the cathode 105 are controlled by the control electrode and injected into the thin hole transport layer 108 and further injected into the light-emitting composite layer 103 through the first electron transport layer 104 to participate in the recombination, while the holes from the anode 101 are also injected into the light-emitting composite layer 103; at this time, the size of the first bias signal 112 applied by the control electrode relative to the cathode 105 can be set according to the amount of hole injection from the anode 101, thereby optimizing the luminous efficiency.

[0045] In addition, when the driving signal 106 is actually loaded, in addition to the following Figure 6 Loaded between cathode 105 anode 101, can also be as Figure 7 As shown, the load is between the conductive surface layer and the anode 101 (for scenario 2, the load is between the conductive surface layer and the cathode 105).

[0046] Typical Scenario 2

[0047] like Figure 3 、 Figure 4 As shown, the unidirectional throttling current gate structure 107 is arranged between the first hole transport layer 102 and the anode 101, and the unidirectional throttling current gate structure 107 includes a thin electron transport layer 113, a second hole transport layer 114 and a second control electrode 115; the film thickness of the thin electron transport layer 113 is less than the thickness of the first hole transport layer 102 and / or the second hole transport layer 114; the thin electron transport layer 113 is directly or through the second conductive surface layer 116 adjacent to the first hole transport layer 102 and stacked electrically connected The second hole transport layer 114 is arranged between the thin electron transport layer 113 and the anode 101; the second regulation electrode 115 is electrically connected to the thin electron transport layer 113, and forms a third loop with the second hole transport layer 114 and the anode 101 to apply a second bias signal; the second bias signal is used to regulate the number of holes conducted from the anode 101 to the thin electron transport layer 113 and further conducted to the light-emitting composite layer 103 and the amount of holes participating in the recombination, so as to regulate the luminous efficiency of the device.

[0048] In scenario 2 of this embodiment, the third loop is further connected in series with a second current-limiting resistor.

[0049] In scenario 2, the thin electron transport layer 113 is disposed between the first hole transport layer 102 and the second hole transport layer 114, and the control electrode is disposed around the same layer of the thin electron transport layer 113. Figure 8 、 Figure 9 As shown, the control electrodes are arranged in a network-like manner on the same layer of the thin electron transport layer 113 in a cross-arranged manner.

[0050] Optionally, an insulating layer is further provided between the control electrode and the second hole transport layer 114 , and an insulating layer is also provided between the control electrode and the first hole transport layer 102 .

[0051] In addition, in this embodiment, the first bias signal 112 or the second bias signal is a current-type driving signal 106 or a voltage-type driving signal 106 ; the voltage-type driving signal 106 includes an adjustable DC power supply, an energy storage capacitor, or a high or low potential node.

[0052] It is worth mentioning that the greater the voltage / current of the first bias signal 112 and the second bias signal, the greater the carriers injected, and the concentration of the carriers participating in the recombination is controlled to increase to achieve luminescence regulation.

[0053] In this embodiment, the light-emitting composite layer 103 is LED, OLED or QLED;

[0054] Among them, when the light-emitting composite layer 103 is the OLED, based on scenario 1, the unidirectional throttling current gate structure 107 is arranged between the cathode 105 and the first electron transport layer 104, and a first hole injection layer is also arranged between the first hole transport layer 102 and the anode 101; when the light-emitting composite layer 103 is the OLED, based on scenario 2, the unidirectional throttling current gate structure 107 is arranged between the first hole transport layer 102 and the anode 101, and a first electron injection layer is also arranged between the first electron transport layer 104 and the cathode 105.

[0055] The technical principles of Scenario 2 are similar to those of Scenario 1 and will not be repeated here.

[0056] Scenario 3

[0057] In this implementation scenario 3, the device includes a first unidirectional throttling current gate structure 107 disposed between the cathode 105 and the first electron transport layer 104 and a second unidirectional throttling current gate structure 107 disposed between the first hole transport layer 102 and the anode 101 .

[0058] The specific structure of scenario 3 can be obtained by combining scenario 1 and scenario 2, and will not be described here.

[0059] The above describes in detail the preferred embodiments of the present invention. It should be understood that those skilled in the art can make numerous modifications and variations based on the concepts of the present invention without inventive effort. Therefore, any technical solutions that can be derived by those skilled in the art through logical analysis, reasoning, or limited experimentation based on the concepts of the present invention and the prior art should be within the scope of protection defined by the claims.

Claims

1. A unidirectional current-cutoff current gate-regulated light-emitting device, characterized in that: The device comprises in sequence: an anode, a first hole transport layer, a light-emitting composite layer, a first electron transport layer, and a cathode; a first circuit is formed between the anode and the cathode and a driving signal is applied, and electrons and holes are injected into the light-emitting composite layer to compositely emit light; The device further comprises a unidirectional throttling current gate structure; the unidirectional throttling current gate structure is arranged between the cathode and the first electron transport layer or between the first hole transport layer and the anode; the unidirectional throttling current gate structure is configured as: When the unidirectional throttling current gate structure is arranged between the cathode and the first electron transport layer, the unidirectional throttling current gate structure includes a thin hole transport layer, a second electron transport layer and a first regulating electrode; the film thickness of the thin hole transport layer is less than the thickness of the first electron transport layer and / or the second electron transport layer; the thin hole transport layer is directly or through a first conductive surface layer and is electrically connected to the adjacent stack of the first electron transport layer, and the second electron transport layer is arranged between the thin hole transport layer and the cathode; the first regulating electrode is electrically connected to the thin hole transport layer, and forms a second loop with the second electron transport layer and the cathode to apply a first bias signal; the first bias signal is used to regulate the number of electrons conducted from the cathode to the thin hole transport layer and further conducted to the light-emitting composite layer and the amount of electrons participating in the composite, so as to regulate the luminous efficiency of the device; When the unidirectional throttling current gate structure is arranged between the first hole transport layer and the anode, the unidirectional throttling current gate structure includes a thin electron transport layer, a second hole transport layer and a second regulating electrode; the film thickness of the thin electron transport layer is less than the thickness of the first hole transport layer and / or the second hole transport layer; the thin electron transport layer is directly or through a second conductive surface layer and is electrically connected to the adjacent stack of the first hole transport layer, and the second hole transport layer is arranged between the thin electron transport layer and the anode; the second regulating electrode is electrically connected to the thin electron transport layer, and forms a third loop with the second hole transport layer and the anode to apply a second bias signal; the second bias signal is used to regulate the number of holes conducted from the anode to the thin electron transport layer and further conducted to the light-emitting composite layer and the amount of holes participating in the recombination, so as to regulate the luminescence efficiency of the device.

2. A unidirectional current-cutoff current gate controlled light-emitting device as claimed in claim 1, characterized in that: The second loop is further connected in series with a first current limiting resistor, or the third loop is further connected in series with a second current limiting resistor.

3. A unidirectional current-cutoff current gate-controlled light-emitting device as claimed in claim 1, characterized in that: The first bias signal or the second bias signal is a current-type driving signal or a voltage-type driving signal; the voltage-type driving signal includes an adjustable direct current power supply, an energy storage capacitor, or a high or low potential node.

4. A unidirectional current-cutoff current gate controlled light-emitting device as claimed in claim 1, characterized in that: The light-emitting composite layer is LED, OLED or QLED; Among them, when the light-emitting composite layer is the OLED, if the one-way throttling current gate structure is arranged between the cathode and the first electron transport layer, a first hole injection layer is also arranged between the first hole transport layer and the anode; when the light-emitting composite layer is the OLED, if the one-way throttling current gate structure is arranged between the first hole transport layer and the anode, a first electron injection layer is also arranged between the first electron transport layer and the cathode.

5. A unidirectional current-cutoff current gate-controlled light-emitting device as claimed in claim 1, characterized in that: The unidirectional throttling current gate structure is arranged between the cathode and the first electron transport layer, the thin hole transport layer is arranged between the first electron transport layer and the second electron transport layer, and the regulating electrode is arranged around the same layer of the thin hole transport layer.

6. A unidirectional current-cutoff current gate-controlled light-emitting device as claimed in claim 5, characterized in that: The control electrodes are arranged in a network-like manner on the same layer of the thin hole transport layer and are cross-arranged.

7. A unidirectional current-cutoff current gate controlled light-emitting device as claimed in claim 1, characterized in that: The unidirectional throttling current gate structure is arranged between the first hole transport layer and the anode, the thin electron transport layer is arranged between the first hole transport layer and the second hole transport layer, and the regulating electrode is arranged around the same layer of the thin electron transport layer.

8. A unidirectional current-cutoff current gate-controlled light-emitting device as claimed in claim 7, characterized in that: The regulating electrodes are arranged in a network-like manner on the same layer of the thin electron transport layer and are cross-arranged.

9. A unidirectional current-cutoff current gate-controlled light-emitting device as claimed in claim 7, characterized in that: An insulating layer is further provided between the regulating electrode and the second hole transport layer, and an insulating layer is also provided between the regulating electrode and the first hole transport layer.

10. The unidirectional current-cutoff current gate controlled light-emitting device according to claim 1, characterized in that: The device includes a first unidirectional throttling current gate structure disposed between the cathode and the first electron transport layer and a second unidirectional throttling current gate structure disposed between the first hole transport layer and the anode.

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