Unidirectional current blocking current grid regulating light emitting device

Abstract

The application discloses a unidirectional current barrier regulation and control light-emitting device, and relates to the field of photoelectric display, comprising: an anode, a first hole transport layer, a light-emitting recombination layer, a first electron transport layer, a cathode; the anode and the cathode form a first loop and apply a driving signal, and inject electrons and holes into the light-emitting recombination layer to recombine and emit light; the device further comprises a unidirectional throttling current barrier structure; the unidirectional throttling current barrier structure is arranged between the cathode and the first electron transport layer or arranged between the first hole transport layer and the anode; the unidirectional throttling current barrier structure participates in the recombination of the light-emitting recombination layer, and the recombination amount of electrons or the recombination amount of holes is adjusted to regulate and control the light-emitting efficiency of the device, so that the light-emitting efficiency of the device can be effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photoelectric display, in particular to a unidirectional current grid regulation light emitting device. BACKGROUND

[0002] Due to the process conditions, material properties, there is a natural, difficult to eliminate the difference between the mobility of electrons and holes, resulting in the light emitting layer of QLED device, charge carriers often appear serious imbalance. This imbalance not only makes the free state of charge carriers in the compound is difficult to achieve the ideal efficiency, and then have a serious negative impact on the light emitting performance of the whole device, but also has become the key bottleneck restricting the further development and performance improvement of QLED technology. This problem also exists in organic light emitting diode (OLED) device, has become a common problem restricting the further improvement of the performance of the two types of display technology.

[0003] Therefore, how to effectively improve the recombination process of charge carriers, balance the mobility of electrons and holes, and significantly improve the light emitting efficiency and performance of QLED and OLED devices without greatly increasing the cost, has become a key scientific problem and technical challenge to be solved in the current display technology field.

[0004] In the related art, the injection amount of electrons or holes is regulated by using a gate. However, in the process of regulating the gate in current injection or built-in electric field construction, carrier conduction or electric field shielding occurs, which affects the effective injection of the regulated carriers and causes inefficient regulation. SUMMARY

[0005] In view of the shortcomings of the prior art, the technical problem to be solved by the present application is to provide a unidirectional current grid regulation light emitting device, which is designed to effectively regulate the migration amount of carriers by designing a unidirectional current grid, and is more efficient than the related art which regulates the injection amount of electrons or holes by using a gate.

[0006] To achieve the above purpose, the present application provides a unidirectional current grid regulation light emitting device, which comprises in sequence: an anode, a first hole transport layer, a light emitting composite layer, a first electron transport layer, and a cathode; the anode and the cathode form a first loop and apply a driving signal, and inject electrons and holes into the light emitting composite layer to recombine and emit light.

[0007] The device further comprises a unidirectional throttling current grid structure; the unidirectional throttling current grid structure is arranged between the cathode and the first electron transport layer or arranged between the first hole transport layer and the anode; the unidirectional throttling current grid structure is configured to:

[0008] When the unidirectional throttling current grid structure is arranged between the cathode and the first electron transport layer, the unidirectional throttling current grid structure comprises a thin hole transport layer, a second electron transport layer and a first regulating electrode; the film layer 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 electrically connected in a stack adjacent to the first electron transport layer directly or through a first conductive surface 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 with 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 by the cathode to the thin hole transport layer and further to the light-emitting recombination layer to participate in recombination, so as to regulate the light-emitting efficiency of the device.

[0009] When the unidirectional throttling current grid structure is arranged between the first hole transport layer and the anode, the unidirectional throttling current grid structure comprises a thin electron transport layer, a second hole transport layer and a second regulating electrode; the film layer 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 electrically connected in a stack adjacent to the first hole transport layer directly or through a second conductive surface 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 with 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 by the anode to the thin electron transport layer and further to the light-emitting recombination layer to participate in recombination, so as to regulate the light-emitting efficiency of the device.

[0010] In the technical solution, on the one hand, the unidirectional throttling current grid structure can effectively regulate the carrier injection amount, effectively regulate the injection amount of carriers participating in recombination in the light-emitting recombination layer, and effectively regulate and improve the light-emitting efficiency; on the other hand, the technical solution adopts the unidirectional throttling current grid structure, in the case of controlling the carrier injection amount according to the bias signal of the unidirectional throttling current grid structure, the carrier injection can only be 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 reverse flow, and can be accumulated on the thin hole transport layer / thin electron transport layer, which is convenient for injection to the first electron transport layer / first hole transport layer, and further helps to improve the light-emitting recombination efficiency.

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

[0012] The technical solution can limit the current of the first circuit / second circuit, and avoid burning the device due to excessive inter-electrode current.

[0013] In an embodiment, the first bias signal or the second bias signal is a current-mode driving signal or a voltage-mode driving signal; the voltage-mode driving signal comprises an adjustable DC power supply, an energy storage capacitor, or a high / low potential node.

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

[0015] When the light-emitting layer is the OLED, if the unidirectional throttling current grid structure is arranged between the cathode and the first electron transport layer, a first hole injection layer is further arranged between the first hole transport layer and the anode; when the light-emitting layer is the OLED, if the unidirectional throttling current grid structure is arranged between the first hole transport layer and the anode, a first electron injection layer is further arranged between the first electron transport layer and the cathode.

[0016] In the technical solution, the injection layer is arranged to optimize the carrier transport performance of the OLED.

[0017] In an embodiment, the unidirectional throttling current grid 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 at the periphery of the same layer of the thin hole transport layer.

[0018] Further, in an embodiment, the control electrode is arranged in a network shape at the same layer of the thin hole transport layer.

[0019] In an embodiment, the unidirectional throttling current grid 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 at the periphery of the same layer of the thin electron transport layer.

[0020] Further, in an embodiment, the control electrode is arranged in a network shape at the same layer of the thin electron transport layer.

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

[0022] In one embodiment, the device comprises a first unidirectional current blocking current grid structure disposed between the cathode and the first electron transport layer and a second unidirectional current blocking current grid structure disposed between the first hole transport layer and the anode.

[0023] The present application has the following advantages: 1) the present application can effectively regulate the carrier injection amount by setting the unidirectional current blocking current grid structure, can effectively regulate the injection amount of carriers participating in recombination in the light emitting layer, and based on this, can effectively regulate and improve the light emitting efficiency; 2) the present application uses a unidirectional current blocking current grid structure, in the case of controlling the carrier injection amount according to the bias signal of the unidirectional current blocking current grid structure, the carrier injection can only be from the cathode / anode to the first electron transport layer / first hole transport layer, i.e. the carrier is 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, facilitating injection into the first electron transport layer / first hole transport layer, thereby helping to improve the light emitting recombination efficiency. 3) the current grid of the present application has a fast response speed, small shielding effect of the conductive electrode layer, and better penetration of the carrier to the light emitting recombination layer. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is a structure schematic diagram of a light emitting device for regulating electron carriers by a unidirectional current blocking current grid in one embodiment of the present application;

[0025] Figure 2 is a structure schematic diagram of a light emitting device for regulating electron carriers by a unidirectional current blocking current grid in another embodiment of the present application;

[0026] Figure 3 is a structure schematic diagram of a light emitting device for regulating hole carriers by a unidirectional current blocking current grid in one embodiment of the present application;

[0027] Figure 4 is a structure schematic diagram of a light emitting device for regulating hole carriers by a unidirectional current blocking current grid in another embodiment of the present application;

[0028] Figure 5 is a principle schematic diagram of a light emitting device for regulating electron carriers by a unidirectional current blocking current grid in one embodiment of the present application;

[0029] Figure 6 is a principle schematic diagram of a light emitting device for regulating electron carriers by a unidirectional current blocking current grid in another embodiment of the present application;

[0030] Figure 7This is a schematic diagram of the principle of a light-emitting device that modulates electron carriers by a unidirectional current-blocking grid in another specific embodiment of the present invention.

[0031] Figure 8 This is a side view of a thin transport layer structure according to a specific embodiment of the present invention;

[0032] Figure 9 This is a top cross-sectional view of a thin transport layer structure according to a specific embodiment of the present invention. Detailed Implementation

[0033] The embodiments of this patent are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this patent, and should not be construed as limiting this patent.

[0034] In the description of this patent, it should be understood that the terms “center,” “upper,” “lower,” “front,” “back,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used 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, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this patent.

[0035] In the description of this patent, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this patent according to the specific circumstances.

[0036] This invention provides a unidirectional current-blocking gate-controlled light-emitting device, such as... Figures 1-9 As shown, the device sequentially includes: 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; the anode 101 and the cathode 105 form a first circuit and a driving signal 106 is applied, and electrons and holes are injected into the light-emitting composite layer 103 to emit light.

[0037] The device also comprises 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 arranged 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] As shown in Figure 1 , Figure 2 , the unidirectional throttling current gate structure 107 is arranged between the cathode 105 and the first electron transport layer 104, the unidirectional throttling current gate structure 107 comprises a thin hole transport layer 108, a second electron transport layer 109 and a first control 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 a first conductive surface layer 111 electrically connected with the first electron transport layer 104, 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 with the thin hole transport layer 108 and forms a second loop 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 control the number of electrons conducted by the cathode 105 to the thin hole transport layer 108 and further to the light-emitting recombination layer 103 to participate in the recombination of the electron recombination amount, so as to control the light-emitting efficiency of the device.

[0040] In scenario 1 of the embodiment, the second loop also has a first current-limiting resistor in series.

[0041] In scenario 1, the thin hole transport layer 108 is arranged between the first electron transport layer 104 and the second electron transport layer 109, and the control electrode is arranged at the same layer periphery of the thin hole transport layer 108. As shown in Figure 8 , Figure 9 , the control electrode is arranged in a network shape at the same layer intersection of the thin hole transport layer 108.

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

[0043] The current gate control principle of scenario 1 will be briefly described below.

[0044] As shown in Figure 5 , Figure 6As shown, the control electrode applies a positive phase potential to the cathode 105, and the thin hole transport layer 108 and the second electron transport layer 109 are connected. Electrons from the cathode 105 are injected into the thin hole transport layer 108 under the control of the control electrode and further injected into the light-emitting composite layer 103 via the first electron transport layer 104 to participate in recombination. Holes from the anode 101 are also injected into the light-emitting composite layer 103. At this time, the magnitude of the first bias signal 112 applied by the control electrode to the cathode 105 can be set according to the hole injection amount of the anode 101, thereby optimizing the luminous efficiency.

[0045] In addition, when the drive signal 106 is actually loaded, besides... Figure 6 Loaded between cathode 105 and anode 101, or as follows Figure 7 As shown, the conductive surface layer is loaded between the anode 101 (for scenario 2, it is loaded 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 disposed between the first hole transport layer 102 and the anode 101. 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 stacked adjacent to the first hole transport layer 102 and electrically connected. Next, the second hole transport layer 114 is disposed between the thin electron transport layer 113 and the anode 101; the second control electrode 115 is electrically connected to the thin electron transport layer 113, and forms a third circuit with the second hole transport layer 114 and the anode 101 to apply a second bias signal; the second bias signal is used to control the number of holes conducted from the anode 101 to the thin electron transport layer 113 and further conducted to the light-emitting recombination layer 103 to participate in recombination, so as to control the luminous efficiency of the device.

[0048] In scenario 2 of this embodiment, the third circuit is also 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 periphery of the thin electron transport layer 113. Figure 8 , Figure 9 As shown, the control electrodes are arranged in a network pattern and cross-arranged on the same layer as the thin electron transport layer 113.

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

[0051] In addition, in the 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-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 injected carrier, and the control increases the carrier concentration participating in recombination to realize light emission control.

[0053] In the embodiment, the light emitting recombination layer 103 is an LED, an OLED or a QLED.

[0054] When the light emitting recombination layer 103 is the OLED, based on scenario 1, the one-way throttling current grid structure 107 is arranged between the cathode 105 and the first electron transport layer 104, and a first hole injection layer is further arranged between the first hole transport layer 102 and the anode 101; when the light emitting recombination layer 103 is the OLED, based on scenario 2, the one-way throttling current grid structure 107 is arranged between the first hole transport layer 102 and the anode 101, and a first electron injection layer is further arranged between the first electron transport layer 104 and the cathode 105.

[0055] The technical principle of scenario 2 is similar to that of scenario 1, which will not be repeated here.

[0056] Scenario 3

[0057] In the embodiment of scenario 3, the device includes a first one-way throttling current grid structure 107 arranged between the cathode 105 and the first electron transport layer 104 and a second one-way throttling current grid structure 107 arranged between the first hole transport layer 102 and the anode 101.

[0058] The specific structure of scenario 3 can be obtained according to the combination of scenario 1 and scenario 2, which will not be repeated here.

[0059] The preferred embodiments of the present application have been described above in detail. It should be understood that modifications and variations to the present application can be affected by those skilled in the art without departing from the scope of the application. Accordingly, it is intended that all of the subject matter of the above description and the claims be interpreted to encompass all such modifications and changes.

Claims

1. A unidirectional current-blocking gate-controlled 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; the anode and the cathode form a first circuit and a driving signal is applied, and electrons and holes are injected into the light-emitting composite layer to emit light. 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: When the unidirectional throttling current gate structure is disposed 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 stacked adjacent to the first electron transport layer and electrically connected; the second electron transport layer is disposed 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 circuit with the second electron transport layer and the cathode to apply a first bias signal; the first control electrode is disposed in a network on the same layer as the thin hole transport layer; an insulating layer is disposed between the first control electrode and the first electron transport layer, and an insulating layer is also disposed between the first control electrode and the second electron transport layer; the first bias signal is used to control the number of electrons conducted from the cathode to the thin hole transport layer and further conducted to the light-emitting recombination layer to participate in recombination, so as to control the luminous efficiency of the device; When the unidirectional throttling current gate structure is disposed 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 stacked adjacent to the first hole transport layer and electrically connected, and the second hole transport layer is disposed 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 circuit with the second hole transport layer and the anode to apply a second bias signal; the second control electrode is disposed in a network on the same layer as the thin electron transport layer, and an insulating layer is disposed between the second control electrode and the second hole transport layer, and an insulating layer is also disposed between the second control electrode and the first hole transport layer; the second bias signal is used to control the number of holes conducted from the anode to the thin electron transport layer and further conducted to the light-emitting recombination layer to participate in recombination, so as to control the luminous efficiency of the device.

2. The unidirectional current-blocking gate-controlled light-emitting device as described in claim 1, characterized in that, The second circuit is also connected in series with a first current-limiting resistor, or the third circuit is also connected in series with a second current-limiting resistor.

3. The unidirectional current-blocking gate-controlled light-emitting device as described in claim 1, characterized in that, 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 high and low potential nodes.

4. The unidirectional current-blocking gate-controlled light-emitting device as described in claim 1, characterized in that, The light-emitting composite layer is an LED, OLED, or QLED; Wherein, when the light-emitting composite layer is the OLED, if the unidirectional throttling current gate structure is disposed between the cathode and the first electron transport layer, then a first hole injection layer is also disposed between the first hole transport layer and the anode; when the light-emitting composite layer is the OLED, if the unidirectional throttling current gate structure is disposed between the first hole transport layer and the anode, then a first electron injection layer is also disposed between the first electron transport layer and the cathode.

5. A unidirectional current-blocking gate-controlled light-emitting device as described in claim 1, characterized in that, The unidirectional throttling current gate structure is disposed between the cathode and the first electron transport layer, the thin hole transport layer is disposed between the first electron transport layer and the second electron transport layer, and the first control electrode is disposed on the periphery of the thin hole transport layer.

6. The unidirectional current-blocking gate-controlled light-emitting device as described in claim 1, characterized in that, The unidirectional throttling current gate structure is disposed between the first hole transport layer and the anode, the thin electron transport layer is disposed between the first hole transport layer and the second hole transport layer, and the second control electrode is disposed on the periphery of the thin electron transport layer.

7. A unidirectional current-blocking gate-controlled light-emitting device as described in 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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