A stacked light-emitting device based on gate modulation by grayscale value variation

Abstract

This invention discloses a stacked structure light-emitting device based on grayscale value variation and gate control, comprising: multiple light-emitting units, each light-emitting unit sequentially including a first electrode, a light-emitting functional layer, and a second electrode; a gate insulating layer is disposed on the first electrode and / or the second electrode side of the light-emitting unit, and a gate control electrode is disposed on the gate insulating layer; the second electrode of the light-emitting unit is grounded; the first electrode of the light-emitting unit is connected to the drain of a thin-film transistor (TFT) switch; the source of the TFT switch is connected to a data lead; the gate of the TFT switch is connected to a scan lead; the drain of the TFT switch is also connected to the gate of an amplifying field-effect transistor (AFPT); the source of the AFPT is connected to a control voltage source, which provides the required voltage to the source of the AFPT; and the drain of the AFPT is connected to the gate control electrode. This invention can achieve adaptive gate voltage adjustment based on grayscale value variation, saving energy.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic displays, and in particular to a stacked structure light-emitting device based on gate modulation by grayscale value variation. Background Technology

[0002] Light-emitting devices (LEDs) are a crucial component of optoelectronic displays, emitting light to display images or information. Many LEDs operate on the principle that, when an electric current is applied, electrons and holes recombine in the light-emitting layer to form excitons. These excitons recombine, releasing energy and emitting light, as seen in QLEDs (quantum dot light-emitting diodes) and OLEDs (organic light-emitting diodes). These LEDs offer advantages such as rich color reproduction, high contrast, fast response times, wide viewing angles, and energy efficiency. However, their luminous efficiency and brightness are significantly affected by carrier recombination. Optimal device efficiency is typically achieved by combining different functional layers and quantum dots, a process that requires substantial time, material, and human resources. Therefore, gate modulation has emerged. By controlling the gate, a built-in electric field can be created within these LEDs, allowing for the regulation of carrier mobility and thus controlling luminous efficiency, ultimately improving overall luminous efficiency.

[0003] Generally, gate-controlled light-emitting devices require higher luminous efficiency and can save more energy when the grayscale value is larger. However, existing light-emitting devices rarely achieve adaptive gate voltage adjustment based on individual grayscale value changes when performing uniform gate voltage control, resulting in energy waste. Summary of the Invention

[0004] In view of the aforementioned deficiencies of the prior art, the technical problem to be solved by the present invention is to provide a stacked structure light-emitting device based on grayscale value variation gate control, which aims to achieve adaptive gate voltage adjustment according to grayscale value variation during uniform gate voltage control, thereby saving energy.

[0005] To achieve the above objectives, this invention discloses a stacked structure light-emitting device based on grayscale value variation gate modulation. The stacked structure light-emitting device includes: multiple light-emitting units, each light-emitting unit sequentially including a first electrode, a light-emitting functional layer, and a second electrode; a gate insulating layer is disposed on the first electrode and / or the second electrode side of the light-emitting unit, and a gate modulation electrode is disposed on the gate insulating layer; the second electrode of the light-emitting unit is grounded; the first electrode of the light-emitting unit is connected to the drain of a thin-film transistor (TFT) switch; the source of the TFT switch is connected to a data lead for controlling the brightness of the light-emitting unit; the gate of the TFT switch is connected to a scan lead for controlling the selection of the TFT switch; the drain of the TFT switch is also connected to the gate of an amplifying field-effect transistor (AFPT); the source of the AFPT is connected to a modulation voltage source, which provides the required voltage to the source of the AFPT; the drain of the AFPT is connected to the gate modulation electrode; and an energy storage capacitor is connected to the drain of the TFT switch, which enables the light-emitting unit to continue emitting light, thereby extending the emitting time.

[0006] When the data lead drives the selected light-emitting unit to emit light, the driving voltage of the data lead is also applied to the gate of the amplifying field-effect transistor. With the applied voltage from the control voltage source remaining constant, the driving voltage changes the carrier concentration and conductivity in the channel of the amplifying field-effect transistor, thereby controlling the drain current of the transistor and causing the control gate voltage of the gate control electrode to change according to the driving voltage. The control gate voltage is used to construct an electric field to control the carrier mobility within the light-emitting unit, thus adjusting the luminous efficiency of the light-emitting unit.

[0007] Optionally, multiple light-emitting units are arranged in rows and columns. Each light-emitting unit includes a red light-emitting unit, a green light-emitting unit, and a blue light-emitting unit. Adjacent red light-emitting units, green light-emitting units, and blue light-emitting units constitute a light-emitting pixel.

[0008] Optionally, the amplifying field-effect transistors corresponding to each of the red light-emitting units are all connected to the same first control voltage source, the amplifying field-effect transistors corresponding to each of the green light-emitting units are all connected to the same second control voltage source, and the amplifying field-effect transistors corresponding to each of the blue light-emitting units are all connected to the same third control voltage source.

[0009] Optionally, the first regulating voltage source, the second regulating voltage source, and the third regulating voltage source apply different voltages, and the voltages applied by the first regulating voltage source, the second regulating voltage source, and the third regulating voltage source increase sequentially; wherein, the initial luminous efficiency of the red light-emitting unit, the green light-emitting unit, and the blue light-emitting unit decreases sequentially.

[0010] Optionally, the drain of the thin-film transistor switch is connected to the gate of the amplifying field-effect transistor via a first step-down resistor, the first step-down resistor being used to ensure that the voltage applied from the drain of the thin-film transistor switch to the gate of the amplifying field-effect transistor meets the requirements.

[0011] Optionally, the light-emitting unit is a quantum dot light-emitting diode, and the light-emitting functional layer includes a hole transport layer, a quantum dot light-emitting layer, and an electron transport layer.

[0012] Optionally, the light-emitting unit is an organic light-emitting diode, and the light-emitting functional layer includes a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, and an electron injection layer.

[0013] The beneficial effects of this invention are as follows: The drain of the thin-film transistor switch of this invention is also connected to the gate of the amplifying field-effect transistor (AFPT), and the source of the AFPT is connected to a control voltage source. The control voltage source provides the required voltage to the source of the AFPT, and the drain of the AFPT is connected to the gate control electrode. When the data lead drives the selected light-emitting unit to emit light, the driving voltage of the data lead is also applied to the gate of the AFPT. With the voltage applied by the control voltage source remaining constant, the driving voltage changes the carrier concentration and conductivity in the channel of the AFPT, thereby controlling the drain current of the AFPT and causing the control gate voltage of the gate control electrode to change according to the driving voltage. This invention, through the configuration of the AFPT, allows the AFPT to determine the applied control gate voltage based on the driving voltage, and the driving voltage also determines the grayscale value of the light-emitting unit. Therefore, this invention can achieve adaptive gate voltage adjustment based on changes in grayscale value. Compared to existing technologies that use one-to-one gate voltage regulation to adapt to changes in grayscale values, this invention allows multiple light-emitting units to share a single regulation voltage source and achieve adaptive gate voltage adjustment based on changes in grayscale values. This effectively reduces the complexity of the gate regulation circuit and saves energy.

[0014] In summary, this invention can adaptively adjust the gate voltage based on changes in grayscale values ​​during unified gate voltage control, thereby saving energy. Attached Figure Description

[0015] Figure 1This is a schematic diagram of a stacked light-emitting device based on gate modulation by grayscale value variation according to a specific embodiment of the present invention;

[0016] Figure 2 This is a schematic diagram of the structure of a light-emitting unit provided in a specific embodiment of the present invention;

[0017] Figure 3 This is a schematic diagram of a stacked structure light-emitting device with multiple light-emitting units based on gate modulation of grayscale value according to a specific embodiment of the present invention;

[0018] Figure 4 This is a schematic diagram of a full-color stacked light-emitting device based on gate modulation by grayscale value variation, provided in a specific embodiment of the present invention. Detailed Implementation

[0019] This invention discloses a driving method for a stacked structure light-emitting device based on gate modulation using grayscale value variation. Those skilled in the art can refer to the content of this document and appropriately modify the technical details to implement it. It should be particularly noted that all similar substitutions and modifications are obvious to those skilled in the art and are considered to be included in this invention. The methods and applications of this invention have been described through preferred embodiments. Those skilled in the art can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit, and scope of this invention to implement and apply the technology of this invention.

[0020] According to the applicant's research, gate-controlled light-emitting devices generally require higher luminous efficiency and can save more energy when the grayscale value is larger. However, existing light-emitting devices, when uniformly controlled by a gate voltage, rarely achieve adaptive gate voltage adjustment based on individual grayscale value changes, leading to energy waste. That is, when controlling multiple light-emitting diodes with a single control voltage, it is impossible to make different adaptive adjustments for different grayscale value changes of each light-emitting diode.

[0021] Therefore, embodiments of the present invention provide a stacked structure light-emitting device based on gate modulation by grayscale value variation, such as... Figure 1As shown, the stacked structure light-emitting device includes: multiple light-emitting units 101, each light-emitting unit 101 sequentially including a first electrode, a light-emitting functional layer, and a second electrode; a gate insulating layer 102 is disposed on the first electrode and / or second electrode side of the light-emitting unit 101, and a gate control electrode 103 is disposed on the gate insulating layer 102; the second electrode of the light-emitting unit 101 is grounded, the first electrode of the light-emitting unit 101 is connected to the drain of a thin-film transistor switch 104, the source of the thin-film transistor switch 104 is connected to a data lead 105 for controlling the brightness of the light-emitting unit 101, and the gate of the thin-film transistor switch 104 is connected to a data lead 105 for controlling the brightness of the light-emitting unit 101. The thin-film transistor switch 104 is configured with a scanning lead 106 for selection. The drain of the thin-film transistor switch 104 is also connected to the gate of the amplifying field-effect transistor 107. The source of the amplifying field-effect transistor 107 is connected to a regulating voltage source 108, which provides the required voltage to the source of the amplifying field-effect transistor 107. The drain of the amplifying field-effect transistor 107 is connected to the gate regulating electrode 103. The drain of the thin-film transistor switch 104 is also connected to an energy storage capacitor 109, which is used to make the light-emitting unit 101 continue to emit light, thereby extending the light emission time.

[0022] It should be noted that in this embodiment of the invention, the regulating voltage source 108 corresponds to multiple light-emitting units 101. Through the arrangement and connection method of the amplifying field-effect transistor 107, this embodiment allows the amplifying field-effect transistor 107 to control the drain current output by adjusting the grayscale value driving voltage applied to its gate, while keeping its source voltage constant, thereby controlling the regulating gate voltage applied to the gate regulating electrode 103. This achieves adaptive gate voltage adjustment based on grayscale value changes during uniform gate voltage regulation. In this embodiment, the energy storage capacitor 109 can extend the light-emitting state, resulting in clearer light-emitting imaging.

[0023] Figure 1 In this text, S, G, and D are abbreviations for the source, gate, and drain of the thin-film transistor switch 104 and the amplifying field-effect transistor 107, respectively. The gate of the thin-film transistor switch 104 and the amplifying field-effect transistor 107 is not the gate control electrode 103.

[0024] When the data lead 105 drives the selected light-emitting unit 101 to emit light, the driving voltage of the data lead 105 is also applied to the gate of the amplifying field-effect transistor 107. When the voltage applied by the regulating voltage source 108 remains unchanged, the driving voltage changes the carrier concentration and conductivity in the channel of the amplifying field-effect transistor 107, thereby controlling the drain current of the amplifying field-effect transistor 107, so that the regulating gate voltage of the gate regulating electrode 103 changes according to the change of the driving voltage. The regulating gate voltage is used to construct an electric field to regulate the carrier mobility in the light-emitting unit 101 and adjust the luminous efficiency of the light-emitting unit 101.

[0025] Multiple light-emitting units 101 can be arranged as follows Figure 3 As shown. Figure 3 The light-emitting units 101 that are connected to the same regulating voltage source 108 are of the same color.

[0026] In this specific embodiment, such as Figure 2 As shown, each light-emitting unit 101 includes a first electrode, a light-emitting functional layer, and a second electrode, and each light-emitting unit 101 is provided with a gate insulating layer 102 and a gate control electrode 103.

[0027] In this specific embodiment, multiple light-emitting units 101 are arranged in rows and columns. Each light-emitting unit 101 includes red, green, and blue light-emitting units, and adjacent red, green, and blue light-emitting units constitute a light-emitting pixel. When the light-emitting unit 101 includes red, green, and blue light-emitting units, this stacked structure light-emitting device is a full-color stacked structure light-emitting device, which can be used as follows... Figure 4 As shown.

[0028] It should be noted that the combination of different color light-emitting units 101 can enable the device in the embodiment of the present invention to achieve full color.

[0029] Furthermore, in this specific embodiment, the amplifying field-effect transistors corresponding to each red light-emitting unit are all connected to the same first control voltage source, the amplifying field-effect transistors corresponding to each green light-emitting unit are all connected to the same second control voltage source, and the amplifying field-effect transistors corresponding to each blue light-emitting unit are all connected to the same third control voltage source. For example... Figure 4 As shown, light-emitting units of different colors are connected to different control voltage sources to facilitate subsequent gate control.

[0030] It should be noted that when there are three different colored light-emitting units, the initial luminous efficiency of the three different colored light-emitting units is different, so the required luminous efficiency improvement is also different, and the applied initial gate voltage is also different. Therefore, three different control gate voltage sources are required.

[0031] Furthermore, in this specific embodiment, the first regulating voltage source, the second regulating voltage source, and the third regulating voltage source apply different voltages, and the voltages applied by the first regulating voltage source, the second regulating voltage source, and the third regulating voltage source increase sequentially; wherein, the initial luminous efficiency of the red light-emitting unit, the green light-emitting unit 1, and the blue light-emitting unit decreases sequentially.

[0032] In this specific embodiment, the drain of the thin-film transistor switch 104 is connected to the gate of the amplifying field-effect transistor 107 through a first step-down resistor. The first step-down resistor is used to ensure that the voltage applied by the drain of the thin-film transistor switch 104 to the gate of the amplifying field-effect transistor 107 meets the requirements.

[0033] It should be noted that in some scenarios, the driving voltage may be much greater than the limit of the gate voltage of the amplifying field-effect transistor 107. Therefore, a first step-down resistor is needed to reduce the voltage. This ensures that the driving voltage can enable the amplifying field-effect transistor 107 to work normally, while preventing the amplifying field-effect transistor 107 from burning out due to excessive voltage and current.

[0034] In this specific embodiment, the light-emitting unit 101 is a quantum dot light-emitting diode, and the light-emitting functional layer includes a hole transport layer, a quantum dot light-emitting layer, and an electron transport layer.

[0035] In another specific embodiment, the light-emitting unit 101 is an organic light-emitting diode, and the light-emitting functional layer includes a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, and an electron injection layer.

[0036] In this embodiment of the invention, the drain of the thin-film transistor switch 104 is also connected to the gate of the amplifying field-effect transistor 107. The source of the amplifying field-effect transistor 107 is connected to the regulating voltage source 108, which provides the required voltage to the source of the amplifying field-effect transistor 107. The drain of the amplifying field-effect transistor 107 is connected to the gate regulating electrode 103. When the data lead 105 drives the selected light-emitting unit 101 to emit light, the driving voltage of the data lead 105 is also applied to the gate of the amplifying field-effect transistor 107. When the voltage applied by the regulating voltage source 108 remains constant, the driving voltage changes the carrier concentration and conductivity in the channel of the amplifying field-effect transistor 107, thereby controlling the drain current of the amplifying field-effect transistor 107 and causing the regulating gate voltage of the gate regulating electrode 103 to change according to the change of the driving voltage. In this embodiment of the invention, by configuring the amplifying field-effect transistor 107, the amplifying field-effect transistor 107 can determine the applied control gate voltage according to the magnitude of the driving voltage. Simultaneously, the magnitude of the driving voltage also determines the grayscale value of the light-emitting unit 101. Therefore, this embodiment of the invention can achieve adaptive gate voltage adjustment based on changes in grayscale value. Compared to the prior art that adapts to grayscale value changes through one-to-one gate voltage control, this embodiment of the invention allows multiple light-emitting units 101 to share a single control voltage source 108, achieving adaptive gate voltage adjustment based on grayscale value changes. This effectively reduces the complexity of the gate control circuit and saves energy.

[0037] In summary, the embodiments of the present invention can achieve adaptive gate voltage adjustment based on changes in grayscale values ​​when performing unified gate voltage control, thereby saving energy.

[0038] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0039] The various embodiments in this specification are described in a related manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions of the method embodiments.

[0040] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention are included within the scope of protection of the present invention.

Claims

1. A stacked structure light emitting device based on gray scale value change gate regulation, characterized in that, The stacked structure light emitting device comprises: a plurality of light emitting units, the light emitting units sequentially comprise a first electrode, a light emitting functional layer, and a second electrode; the first electrode and / or the second electrode of the light emitting units are provided with a gate insulating layer, and a gate control electrode is arranged on the gate insulating layer; the second electrode of the light emitting units is grounded, the first electrode of the light emitting units is connected with the drain of a thin film transistor switch, the source of the thin film transistor switch is connected with a data lead wire for controlling the brightness of the light emitting units, the gate of the thin film transistor switch is connected with a scanning lead wire for controlling the gating of the thin film transistor switch, and the drain of the thin film transistor switch is also connected with the gate of an amplification field effect transistor; the source of the amplification field effect transistor is connected with a control voltage source for providing the required voltage to the source of the amplification field effect transistor; the drain of the amplification field effect transistor is connected with the gate control electrode; the drain of the thin film transistor switch is also connected with an energy storage capacitor, and the energy storage capacitor is used to make the light emitting unit continuously emit light so as to prolong the light emitting time. When the data lead wire drives the gated light emitting unit to emit light, the driving voltage of the data lead wire is also applied to the gate of the amplification field effect transistor; in the case that the voltage applied by the control voltage source is unchanged, the driving voltage changes the carrier concentration and conductivity in the channel of the amplification field effect transistor, thereby controlling the drain current of the amplification field effect transistor, and making the control gate voltage of the gate control electrode change according to the change of the driving voltage; wherein the control gate voltage is used to build an electric field to control the mobility of the carriers in the light emitting unit and adjust the light emitting efficiency of the light emitting unit.

2. The stacked structure light-emitting device based on the gray scale value change gate regulation according to claim 1, wherein, The plurality of light emitting units are arranged in rows and columns, and the light emitting units comprise red light emitting units, green light emitting units and blue light emitting units, and adjacent red light emitting units, green light emitting units and blue light emitting units constitute a light emitting pixel.

3. The stacked structure light-emitting device based on the gray scale value change gate regulation according to claim 2, characterized in that, The amplification field effect transistors corresponding to each red light emitting unit are connected to the same first control voltage source, the amplification field effect transistors corresponding to each green light emitting unit are connected to the same second control voltage source, and the amplification field effect transistors corresponding to each blue light emitting unit are connected to the same third control voltage source.

4. The stacked structure light-emitting device based on the gray scale value change gate regulation according to claim 3, characterized in that, The first control voltage source, the second control voltage source and the third control voltage source apply different voltages, and the voltages applied by the first control voltage source, the second control voltage source and the third control voltage source increase in turn; wherein the initial light emitting efficiencies of the red light emitting units, the green light emitting units and the blue light emitting units decrease in turn.

5. The stacked structure light-emitting device based on the gray scale value change gate regulation according to claim 1, wherein, The drain of the thin film transistor switch is connected with the gate of the amplification field effect transistor through a first voltage dropping resistor, and the first voltage dropping resistor is used to make the voltage applied by the drain of the thin film transistor switch to the gate of the amplification field effect transistor meet the requirements.

6. The stacked structure light-emitting device based on the gray scale value change gate regulation according to claim 1, wherein, The light-emitting unit is a quantum dot light-emitting diode, and the light-emitting functional layer comprises a hole transport layer, a quantum dot light-emitting layer and an electron transport layer.

7. The stacked structure light-emitting device based on the gray scale value change gate regulation according to claim 1, wherein, The light-emitting unit is an organic light-emitting diode, and the light-emitting functional layer comprises a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer and an electron injection layer.

Images