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EP-4044263-B1 - MANUFACTURING METHOD OF A µLED LIGHT-EMITTING AND DISPLAY DEVICE WITH SINGLE-ENDED ELECTRICAL CONTACT AND SINGLE-ENDED CARRIER INJECTION

EP4044263B1EP 4044263 B1EP4044263 B1EP 4044263B1EP-4044263-B1

Inventors

  • GUO, TAILIANG
  • LIU, YE
  • WU, Chaoxing
  • LI, Dianlun
  • ZHANG, YONGAI
  • ZHOU, Xiongtu
  • WANG, KUN

Dates

Publication Date
20260506
Application Date
20200831

Claims (16)

  1. A manufacturing method of a µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection, comprising more than one pixel unit, each pixel unit sequentially comprising a lower pixel electrode (101), µLED chips (3), an insulating layer (202), and an upper pixel electrode (201) from bottom to top, wherein the µLED chips (3) directly contact with the lower pixel electrode (101) , external carriers are injected into the µLED chips (3) through the lower pixel electrode (101), the insulating layer (202) is set to prevent the external carriers from being injected into the µLED chips (3) through the upper pixel electrode (201), and the µLED chips (3) are lit by an alternating electric field applied between the upper pixel electrode (201) and the lower pixel electrode (101); the µLED chips (3) comprise a P-type semiconductor layer (301), a light-emitting layer and a N-type semiconductor layer (302), and the P-type semiconductor layer (301), the light-emitting layer and the N-type semiconductor layer (302) are stacked to form a semiconductor junction capable of emitting light under the action of an electric field; the semiconductor junction in the µLED chips (3) comprises a single PN junction, a single heterojunction, a composite PN junction comprising a plurality of PN junctions, or a combined semiconductor junction comprising a PN junction and a heterojunction; the manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection, comprising the following steps: S1: preparing a lower pixel electrode (101) array and a connection wire thereof on the surface of a base plate; S2: disposing a patterned µLED chip (3) array on the surface of the base plate of a substrate; S3: providing an insulating layer (202) on the surfaces of the µLED chip array, the lower pixel electrode array and a connection wire thereof using an insulating layer manufacturing process; and S4: preparing an upper pixel electrode (201) array and a connection wire thereof on the surface of the insulating layer (202).
  2. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the semiconductor junction is located on the surface or in the inside of the µLED chips (3).
  3. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the p-type semiconductor layer (301) has a thickness of 1 nm-2.0 µm, the light-emitting layer has a thickness of 1 nm-1.0 µm, and the n-type semiconductor layer (302) has a thickness of 1 nm-2.5 µm.
  4. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein one or more than two µLED chips (3) are present in each pixel unit.
  5. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 4, wherein the size of the upper pixel electrode (201) or the lower pixel electrode (101) in a pixel unit is not smaller than the sum of the sizes of all the µLED chips (3) in the pixel unit.
  6. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the µLED chips (3) have a size of 1 nm to 1000 µm and a thickness of 1 nm to 100 µm.
  7. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein at least one of the upper pixel electrode (201) and the lower pixel electrode (101) is a transparent electrode, and wherein the material of the transparent electrode comprises graphene, indium tin oxide, carbon nanotubes, silver nanowires, copper nanowires or a combination thereof, and the material of a non-transparent electrode comprises gold, silver, aluminum, copper or a combination thereof.
  8. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the material of the insulating layer (202) has a light transmittance of greater than or equal to 80% in a visible light range, and the material is an organic insulating material, an inorganic insulating material, air or a combination thereof.
  9. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the insulating layer (202) has a thickness of 1 nm to 1000 µm.
  10. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the waveform of the alternating electric field comprises sine wave, triangle wave, square wave, pulse or a combination thereof.
  11. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the alternating electric field has a frequency of 1 Hz to 1000 MHz.
  12. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the µLED chips (3) emit light (comprising infrared light or ultraviolet light) of different colors by selecting different semiconductor materials.
  13. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the µLED chips (3) can emit light of the same color or light of different mixed colors by using a composite PN junction or a combined semiconductor junction.
  14. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein the µLED light-emitting and display device is prepared on a rigid material comprising glass, ceramics and sapphire or prepared on a flexible material comprising PI.
  15. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein S2 specifically comprises: arranging µLED chips (3) emitting light of different colors on the surface of the base plate of the substrate by means of inkjet printing, silk-screen printing, spin coating, brush coating, roll coating, chemical self-assembly, electromagnetic self-assembly and the like.
  16. The manufacturing method of the µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection according to claim 1, wherein S2 specifically comprises: arranging a patterned µLED chip array on the surface of the base plate of the substrate using an in-situ growth method.

Description

BACKGROUND OF THE INVENTION 1. Technical Field The invention relates to the field of display and light-emitting device design, in particular to a µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection, and a manufacturing method thereof. 2. Description of Related Art In the technical field of flat panel display, µLED has many advantages, and the most notable advantage is low power consumption, high brightness, ultra-high definition, high color saturation, higher response speed, longer service life and higher work efficiency and the like. It is a new transformational display technology and is expected to replace almost all applications of TFT liquid crystal display in the field of flat panel display. The current µLED production process follows a traditional LED manufacturing method, in which a pn junction grows on the base surface by various thin film growth methods and then is cut into micro-sized LED chips. The µLED chips are transferred to a circuit substrate by various mechanical tools, and the accurate electrical contact between the µLED chips and a driving electrode needs to be achieved through accurate alignment and bonding, so the device manufacturing efficiency is low and the yield is low. In order to solve the above problems and improve the efficiency of the µLED industry, it is urgent to develop and design a new µLED. Patent CN 104465921 A discloses a light emitting diode integrated chip of a capacitive structure and a manufacturing method of the light emitting diode integrated chip. The chip comprises an outer connecting port, a transparent electrode layer with the conductive capacity, insulating medium filling layers and light emitting source light emitting diode chips. A capacitor structure is formed through the light emitting diode chips of a certain number and the insulating medium filling layers, and two insulating medium filling layers are conductive medium layers, so that the capacitor structure is formed, and the whole structure is connected with the outer connecting port through a lead Pad point on an electrode. According to the light emitting diode integrated chip, a novel drive mode and the novel chip structure are adopted, an insulating medium material with a high dielectric constant is adopted, the chip can be directly driven by an alternating current power source, and the chip is easy to manufacture and low in cost. Patent US 2019/004105 A1 discloses functional test methods useful for fabricating products containing Light Emitting Diode (LED) structures. In particular, LED arrays are functionally tested by injecting current via a displacement current coupling device using a field plate comprising of an electrode and insulator placed in close proximity to the LED array. A controlled voltage waveform is then applied to the field plate electrode to excite the LED devices in parallel for high-throughput. A camera records the individual light emission resulting from the electrical excitation to yield a function test of a plurality of LED devices. Changing the voltage conditions can excite the LEDs at differing current density levels to functionally measure external quantum efficiency and other important device functional parameters. Spectral filtering is used to improve measurement contrast and LED defect detection. External light irradiation is used to excite the LED array and improve onset of charge injection light emission and throughput. Patent US 2015/380390 A1 discloses a LED package (10) suitable for capacitive driving, comprising at least one pair of anti-parallel oriented LEDs (20, 30). These LEDs are provided with electrical terminals (21, 22, 31, 32) at opposing surfaces of the LEDs. The LEDs are sandwiched between two substantially parallel oriented substrates (40, 50) of a dielectric material, which substrates are provided on their facing surfaces (41, 51) with a film (42, 52) of electrically conductive material, so that electrical contacts (61, 62) are available between the electrical terminals and the films of electrically conductive material. The LED package is cheap, technically simple, reliable and small-dimensioned, and can be applied in a LED assembly. A method for manufacturing such LED packages is claimed as well. BRIEF SUMMARY OF THE INVENTION In view of this, the purpose of the present invention is to propose a µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection and a manufacturing method of the µLED light-emitting and display device, which avoids the complicated bonding process and is expected to improve the market competitiveness of the µLED light-emitting and display device. The present invention is achieved using the following scheme: a manufacturing method of a µLED light-emitting and display device with single-ended electrical contact and single-ended carrier injection comprising more than one pixel unit, each pixel unit sequentially comprising