Inverted Green Quantum Dot Thin Film Electroluminescent Device

A technology for electroluminescent devices and quantum dots to emit light. It is applied in the direction of electro-solid devices, electrical components, semiconductor devices, etc., which can solve the problem of inability to meet the requirements of hole injection, high hole injection barrier, and difficult hole injection. question

Inactive Publication Date: 2017-12-22
SHANGHAI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, holes in traditional quantum dot thin film electroluminescent devices (QLED) are not easy to inject, and hole injection materials with high HOMO (Highest Occupied Molecular Orbital, highest occupied molecular orbital) energy level are needed to help hole injection
Especially for green light quantum dot thin film electroluminescent devices, the HOMO energy level of green light quantum dots is generally large, about 6.5eV, while the work function of general transparent anodes is less than 5.0eV, the difference between the two is far, resulting in QLED The hole injection barrier in the device is generally high, and the HOMO energy level of commonly used hole injection materials is generally 5.0eV to 5.5eV, which cannot meet the requirements of hole injection.

Method used

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  • Inverted Green Quantum Dot Thin Film Electroluminescent Device
  • Inverted Green Quantum Dot Thin Film Electroluminescent Device
  • Inverted Green Quantum Dot Thin Film Electroluminescent Device

Examples

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preparation example Construction

[0049] In addition, the present invention also provides a method for preparing the above-mentioned inverted green light quantum dot thin film electroluminescent device 10, such as image 3 As shown, the method includes the following steps S110-S140.

[0050] S110, providing a substrate, and forming a cathode on the substrate.

[0051] The material of the substrate can be glass, and the substrate can be ultrasonically treated with detergent, acetone, ethanol and isopropanol for 15 minutes each. Then vapor deposition, sputtering, sputtering or electrochemical vapor deposition on the substrate to form the cathode. The material of the cathode can be indium tin oxide (ITO), fluorine-doped tin oxide (FTO), aluminum-doped zinc oxide (AZO), indium-doped zinc oxide (IZO), etc., and the thickness of the cathode is 80nm-200nm.

[0052] Preferably, indium tin oxide (ITO) is sputtered onto the glass substrate by sputtering.

[0053] In this embodiment, after the cathode is formed on the...

Embodiment 1

[0065] The structure of the inverted green light quantum dot thin film electroluminescence device is a substrate, a cathode, an electron transport layer, a green light quantum dot light-emitting layer, a hole balance layer, a hole transport layer and an anode. Wherein the hole transport layer includes a second hole transport layer and a first hole transport layer. The second hole transport layer is in direct contact with the hole transport layer. The thickness of the hole balance layer is 8nm, and the material of the hole balance layer is the third hole transport material (HTL3), and HTL3 is 6,6-bis(4-9 hydrogen-carbazol-9-yl)phenyl)- 6 Hydrogen-pyrrole[3,2,1-de]acridine (BCPPA). The thickness of the second hole transport layer is 15nm, and the material of the second hole transport layer is the mixture that the first hole transport material (HTL1) and the 3rd hole transport material (HTL3) form, and wherein HTL1 is tungsten trioxide ( WO 3 ), HTL3 is 6,6-bis(4-9hydrogen-car...

Embodiment 2

[0071] The thickness of the hole balance layer in the inverted green light quantum dot thin film electroluminescence device of this embodiment is 5 nm, and the material of the hole balance layer is HTL3, and HTL3 is BCPPA. The thickness of the second hole transport layer is 10nm, and the material of the second hole transport layer is a mixture of HTL1 and HTL3, wherein HTL1 is WO 3 , HTL3 for BCPPA, WO 3 The mass ratio to BCPPA is 1:2. The thickness of the first hole transport layer is 20nm, and the material of the first hole transport layer is a mixture of HTL1 and HTL2, wherein HTL1 is WO 3 , HTL2 to BTPD, WO 3 The mass ratio to BTPD is 1:1. All the other are identical with embodiment 1.

[0072] The specific preparation method of the inverted green light quantum dot thin film electroluminescent device is the same as that of Example 1.

[0073] The hole balance layer, the second hole transport layer and the first hole transport layer were tested respectively. The HOMO e...

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Abstract

The invention discloses an inverted green light quantum dot thin film electroluminescent device, which comprises a substrate, a cathode, an electron transport layer, a green light quantum dot luminescent layer, a hole balance layer, a hole transport layer and an anode stacked in sequence. The hole transport layer includes a stacked second hole transport layer and a first hole transport layer. The thickness of the hole balancing layer is 5nm˜10nm. The HOMO energy level of the second hole transport layer is higher than the HOMO energy level of the first hole transport layer, thereby forming a step barrier between the green light quantum dot light-emitting layer and the anode, so as to gradually increase the hole injection of the hole transport layer Ability to meet the hole injection requirements of green light quantum dot thin film electroluminescent devices. Further, the hole balancing layer can prevent the direct contact between the high-mobility first hole transport material and the green light quantum dot light-emitting layer, so as to avoid luminescence quenching.

Description

technical field [0001] The invention relates to the technical field of light-emitting devices, in particular to an electroluminescent device with an inverted green light quantum dot thin film. Background technique [0002] Quantum dots (QDs, quantum dots) are some extremely small semiconductor nanocrystals that cannot be seen by the naked eye, and the particle size is generally less than 10nm. When stimulated by light or electricity, quantum dots can emit colored light. The color of light is determined by the composition, material, size and shape of quantum dots. This feature enables quantum dots to change the color of light emitted by the light source. Because electrons, holes, and excitons are quantum-confined in the three-dimensional direction, the energy band structure of QDs changes from a bulk continuous structure to a discrete energy level structure with molecular characteristics. When the particle size of QDs is equal to or smaller than the Bohr radius of Wannier ex...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01L51/50H01L51/52H01L51/54H01L51/56
CPCH10K50/00H10K50/15H10K50/80H10K71/00
Inventor 曹进周洁谢婧薇魏翔俞浩健
Owner SHANGHAI UNIV
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