CN114784215A - Preparation method of quasi-two-dimensional blue light LED device - Google Patents

Abstract

The invention is suitable for the field of light emitting diodes, and provides a preparation method of a quasi-two-dimensional blue light LED device. In the preparation process of the device, the metal nanoclusters are mixed with the traditional transmission layer, and the electrical property of the original transmission layer is adjusted, so that the effect of balancing carrier transmission is realized, the performance of the perovskite light-emitting device is improved finally, the preparation method has the advantages of simple preparation process and high efficiency, and the problem of low efficiency of the existing blue light quasi-two-dimensional LED device is solved.

Description

A kind of preparation method of quasi-two-dimensional blue LED device

technical field

The invention belongs to the field of light emitting diodes, and in particular relates to a preparation method of a quasi-two-dimensional blue light LED device.

Background technique

Quasi-2D metal halide perovskite materials hold great promise in light-emitting diode and display applications due to their high photoluminescence quantum yield, tunable optical bandgap, excellent color purity, and low-cost solution processability.

However, the photoelectric properties of light-emitting diodes using perovskite materials as light-emitting layers are still far lower than those of organic light-emitting diodes. On the one hand, the crystallization process of the perovskite film solution is difficult to control, resulting in poor crystalline quality and uneven phase distribution of the film, resulting in too low energy transmission efficiency, resulting in excessive non-radiative recombination defects; on the other hand, there is no energy. A suitable transport layer leads to the difficulty of carrier injection, which makes the carrier transport in the device unbalanced, resulting in low device efficiency, which seriously restricts the industrial application of perovskite thin films and their devices. For quasi-2D blue LED devices, due to the large band gap of blue light emission, the HOMO energy level is relatively deep, and the lack of hole transport materials with suitable mobility and energy level has been a problem for the efficiency of quasi-2D blue LED devices. One of the main reasons for the improvement is that we propose a fabrication method for quasi-two-dimensional blue LED devices.

SUMMARY OF THE INVENTION

The purpose of the embodiments of the present invention is to provide a preparation method of a quasi-two-dimensional blue LED device, which aims to solve the problems raised in the above background technology.

To achieve the above object, the present invention provides the following technical solutions:

A preparation method of a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: The PEDOT:PSS solution is deposited on the surface of the substrate in step 1 by spin coating, and post-annealing is performed at 150 °C, and the mixed material of conductive polymer, metal nanocluster and conductive polymer is dissolved in organic reagents After that, it was deposited on the surface of the substrate by spin coating, and then annealed at 150 °C;

Step 3: Dissolve an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 4: Add an appropriate amount of the perovskite precursor solution in step 3 dropwise to the surface of the substrate in step 2, and then prepare a thin film by spin coating, and add 150 microliters of anti-solvent dropwise to the surface of the substrate for a certain period of time. On the surface of the perovskite film, the anti-solvent is one of ethyl acetate, chlorobenzene and toluene, so that the film is rapidly crystallized, and then the film is placed on a heating table for later annealing and crystallization;

Step 5: Put the thin film obtained in Step 4 into an evaporation apparatus, and evaporate the electron transport layer and the metal aluminum electrode.

Further, in the step 2, the conductive polymer is one of PVK, Poly-TPD, PTAA and TFB.

Further, in the step 2, in the mixed material of the metal nanocluster and the conductive polymer, the metal nanocluster is one of oil-soluble gold nanoclusters, oil-soluble silver nanoclusters and oil-soluble copper nanoclusters. kind.

Further, in the step 2, in the mixed material of the metal nanoclusters and the conductive polymer, the proportion of the metal nanoclusters in the mixed material is 5%-55%.

Further, the metal nanoclusters are used to improve hole conductivity.

Further, in the step 2, the organic reagent is one of DMSO, DMF, CB and m-xylene.

Further, in the step 5, the electron transport material is one of TPBi/LiF, TPBi/Liq, Tmpypb/LiF and Tmpypb/Liq.

Compared with the prior art, the beneficial effects of the present invention are:

In the preparation method of the quasi-two-dimensional blue LED device, oil-soluble metal nanoclusters are doped into an organic conductive polymer to effectively improve the injection and transport of hole carriers in the quasi-two-dimensional blue LED device; using metal The molecular properties of nanoclusters allow metals to be doped into the transport layer in another way, using their metallicity to improve the conductivity and carrier mobility of conductive polymers, and at the same time using the ligands of metal nanoclusters to interact with the transport layer. The π-π stacking between benzene rings in the conductive polymer makes the energy level difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the quasi-2D blue perovskite light-emitting layer smaller, which improves the injection of holes. efficiency.

Description of drawings

FIG. 1 is a comparison diagram of film roughness before and after experimental optimization in an embodiment of the present invention.

FIG. 2 is a comparison diagram of the electrical conductivity of thin films before and after experimental optimization in the embodiment of the present invention.

FIG. 3 is a comparison diagram of the carrier mobility of thin films before and after experimental optimization in an embodiment of the present invention.

FIG. 4 is a comparison diagram of device current density and turn-on voltage before and after experimental optimization in an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

Example 1

An embodiment of the present invention provides a method for preparing a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: deposit the PEDOT:PSS solution on the surface of the substrate in step 1 by spin coating, and perform post-annealing at 150°C;

Step 3: Dissolve an appropriate amount of TFB in CB, deposit it on the substrate surface of Step 2 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 4: Dissolve an appropriate amount of PVK and oil-soluble silver nanoclusters in CB, deposit on the substrate surface of Step 3 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 5: Dissolve an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 6: Add an appropriate amount of the perovskite precursor solution in Step 5 to the surface of the substrate in Step 4, and then prepare a thin film by spin coating, using 150 microliters of ethyl acetate as an anti-solvent for a certain period of time , dropwise onto the surface of the perovskite film, so that the film crystallizes rapidly, and then the film is placed on a heating table for later annealing and crystallization;

Step 7: Put the film obtained in Step 6 into an evaporation apparatus, and evaporate the electron transport layer TPBi/Liq and the metal aluminum electrode.

In the embodiment of the present invention, the perovskite film is composed of a quasi-two-dimensional perovskite film, and the quasi-two-dimensional film is constructed by adding long-chain organic groups to the three-dimensional perovskite to enhance the quantum confinement effect, which is the luminescence peak of the device. blue-shift; preferably, the incorporation of metal nanoclusters cannot increase the roughness of the optimized transport layer film by more than 50% compared with that before optimization, and the roughness of the perovskite layer film prepared by spin coating method is increased compared with that before optimization. It cannot exceed 50%; the incorporation of metal nanoclusters improves hole conductivity, improves energy levels, and makes the energy levels of the hole transport layer and the light-emitting layer more matched, thereby improving the hole injection efficiency, which is manifested in the turn-on voltage (brightness of 1 candela voltage per square meter). Referring to Figures 1 to 4, silver nanoclusters are incorporated into the conductive polymer PVK as a dopant as a hole transport layer, which improves the hole mobility of PVK, improves the energy level of PVK, and realizes energy-level matched loading. The carrier injection improves the carrier injection efficiency. Metal nanoclusters are a very good way to improve transport materials because they have both metallic and molecular properties at the transition scale, which can solve the limitations of inorganic silver salts and organic ligands acting alone. By doping at a suitable concentration, the metal nanoparticles will not greatly improve the film-forming properties of the transport layer, and will not affect the film-forming properties of perovskite. The doping of silver nanoclusters can significantly enhance the transport and injection of hole carriers, build a balanced carrier transport, and achieve high-brightness and high-efficiency blue LED device performance.

Example 2

An embodiment of the present invention provides a method for preparing a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: deposit the PEDOT:PSS solution on the surface of the substrate in step 1 by spin coating, and perform post-annealing at 150°C;

Step 3: Dissolve an appropriate amount of Poly-TPD in m-xylene, deposit it on the substrate surface of Step 2 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 4: Dissolve an appropriate amount of PTAA and oil-soluble copper nanoclusters in CB, deposit them on the substrate surface of Step 3 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 5: Dissolve an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 6: Add an appropriate amount of the perovskite precursor solution in Step 5 to the surface of the substrate in Step 4, and then prepare a thin film by spin coating. For a certain period of time, use 150 microliters of chlorobenzene as an anti-solvent, It is added dropwise to the surface of the perovskite film to rapidly crystallize the film, and then the film is placed on a heating table for later annealing and crystallization;

Step 7: Put the film obtained in Step 6 into an evaporation apparatus, and evaporate the electron transport layer TPBi/LiF and the metal aluminum electrode.

Example 3

An embodiment of the present invention provides a method for preparing a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: deposit the PEDOT:PSS solution on the surface of the substrate in step 1 by spin coating, and perform post-annealing at 150°C;

Step 3: Dissolve an appropriate amount of TFB in DMSO, deposit it on the substrate surface of Step 2 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 4: Dissolve an appropriate amount of Poly-TPD and oil-soluble copper nanoclusters in CB, deposit on the substrate surface of Step 3 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 5: Dissolve an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 6: Add an appropriate amount of the perovskite precursor solution in Step 5 to the surface of the substrate in Step 4, and then prepare a thin film by spin coating, using 150 microliters of ethyl acetate as an anti-solvent for a certain period of time , dropwise onto the surface of the perovskite film, so that the film crystallizes rapidly, and then the film is placed on a heating table for later annealing and crystallization;

Step 7: Put the film obtained in Step 6 into an evaporation apparatus, and evaporate the electron transport layer TPBi/Liq and the metal aluminum electrode.

Example 4

An embodiment of the present invention provides a method for preparing a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: deposit the PEDOT:PSS solution on the surface of the substrate in step 1 by spin coating, and perform post-annealing at 150°C;

Step 3: Dissolve an appropriate amount of TFB in DMSO, deposit it on the substrate surface of Step 2 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 4: Dissolve an appropriate amount of PTAA and oil-soluble copper nanoclusters in CB, deposit them on the substrate surface of Step 3 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 5: Dissolve an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 6: Add an appropriate amount of the perovskite precursor solution in Step 5 to the surface of the substrate in Step 4, and then prepare a thin film by spin coating, using 150 microliters of ethyl acetate as an anti-solvent for a certain period of time , dropwise onto the surface of the perovskite film, so that the film crystallizes rapidly, and then the film is placed on a heating table for later annealing and crystallization;

Step 7: Put the thin film obtained in Step 6 into an evaporation apparatus, and evaporate the electron transport layer Tmpypb/Liq and the metal aluminum electrode.

Example 5

An embodiment of the present invention provides a method for preparing a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: deposit the PEDOT:PSS solution on the surface of the substrate in step 1 by spin coating, and perform post-annealing at 150°C;

Step 3: Dissolve an appropriate amount of Poly-TPD in CB, deposit it on the substrate surface of Step 2 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 4: Dissolve an appropriate amount of PVK and oil-soluble silver nanoclusters in CB, deposit on the substrate surface of Step 3 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 5: Dissolve an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 6: Add an appropriate amount of the perovskite precursor solution in Step 5 to the surface of the substrate in Step 4, and then prepare a thin film by spin coating, using 150 microliters of ethyl acetate as an anti-solvent for a certain period of time , dropwise onto the surface of the perovskite film, so that the film crystallizes rapidly, and then the film is placed on a heating table for later annealing and crystallization;

Step 7: Put the thin film obtained in Step 6 into an evaporation apparatus, and evaporate the electron transport layer Tmpypb/Liq and the metal aluminum electrode.

Example 6

An embodiment of the present invention provides a method for preparing a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: deposit the PEDOT:PSS solution on the surface of the substrate in step 1 by spin coating, and perform post-annealing at 150°C;

Step 3: Dissolve an appropriate amount of PTAA and oil-soluble silver nanoclusters in CB, deposit on the substrate surface of Step 2 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 4: Dissolve an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 5: Add an appropriate amount of the perovskite precursor solution in step 4 to the surface of the substrate in step 3, and then prepare a thin film by spin coating, and use 150 microliters of ethyl acetate as an anti-solvent for a certain period of time. , dropwise onto the surface of the perovskite film, so that the film crystallizes rapidly, and then the film is placed on a heating table for later annealing and crystallization;

Step 6: Put the thin film obtained in Step 5 into an evaporation apparatus, and evaporate the electron transport layer Tmpypb/Liq and the metal aluminum electrode.

Example 7

An embodiment of the present invention provides a method for preparing a quasi-two-dimensional blue LED device, comprising the following steps:

Step 1: The ITO substrate was repeatedly cleaned with deionized water, ethanol and acetone, and then cleaned with an ultraviolet ozone machine for 20 minutes;

Step 2: deposit the PEDOT:PSS solution on the surface of the substrate in step 1 by spin coating, and perform post-annealing at 150°C;

Step 3: Dissolve an appropriate amount of PVK and oil-soluble copper nanoclusters in DMF, deposit them on the substrate surface of Step 2 by spin coating in a nitrogen glove box, and perform post-annealing at 150°C;

Step 4: Dissolving an appropriate amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

Step 5: Add an appropriate amount of the perovskite precursor solution in step 4 to the surface of the substrate in step 3, and then prepare a thin film by spin coating, and use 150 microliters of ethyl acetate as an anti-solvent for a certain period of time. , dropwise onto the surface of the perovskite film, so that the film crystallizes rapidly, and then the film is placed on a heating table for later annealing and crystallization;

Step 6: Put the thin film obtained in Step 5 into an evaporation apparatus, and evaporate the electron transport layer Tmpypb/Liq and the metal aluminum electrode.

The working principle of the present invention is:

In the preparation method of the quasi-two-dimensional blue LED device, oil-soluble metal nanoclusters are doped into an organic conductive polymer to effectively improve the injection and transport of hole carriers in the quasi-two-dimensional blue LED device; using metal The molecular properties of nanoclusters allow metals to be doped into the transport layer in another way, using their metallicity to improve the conductivity and carrier mobility of conductive polymers, and at the same time using the ligands of metal nanoclusters to interact with the transport layer. The π-π stacking between benzene rings in the conductive polymer makes the energy level difference between the HOMO energy level of the hole transport layer and the HOMO energy level of the quasi-2D blue perovskite light-emitting layer smaller, which improves the injection of holes. efficiency.

The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, some modifications and improvements can be made without departing from the concept of the present invention, and these should also be regarded as the protection scope of the present invention. , these will not affect the effect of the implementation of the present invention and the practicability of the patent.

Claims (7)

1. A preparation method of a quasi-two-dimensional blue light LED device is characterized by comprising the following steps:

step 1: repeatedly cleaning the ITO substrate by using deionized water, ethanol and acetone respectively, and then cleaning for 20 minutes by using an ultraviolet ozone machine;

step 2: PSS solution is deposited on the surface of the substrate in the step 1 in a spin coating mode, post annealing is carried out at 150 ℃, mixed materials of conductive polymers, metal nanoclusters and conductive polymers are dissolved in organic reagents and then deposited on the surface of the substrate through a spin coating method, and post annealing is carried out at 150 ℃;

and 3, step 3: dissolving a proper amount of lead iodide, phenylbutylammonium bromide and cesium bromide into 1 ml of DMSO solution to form a perovskite precursor solution;

and 4, step 4: dropwise adding a proper amount of the perovskite precursor solution obtained in the step 3 onto the surface of the substrate obtained in the step 2, preparing a film in a spin coating mode, dropwise adding 150 microliters of an anti-solvent onto the surface of the perovskite film within a certain time, wherein the anti-solvent is one of ethyl acetate, chlorobenzene and toluene, so that the film is rapidly crystallized, and then putting the film on a heating table for later annealing crystallization;

and 5: and (4) putting the film obtained in the step (4) into an evaporation instrument, and evaporating an electron transmission layer and a metal aluminum electrode.

2. The method for manufacturing a quasi-two-dimensional blue LED device according to claim 1, wherein in the step 2, the conductive polymer is one of PVK, Poly-TPD, PTAA and TFB.

3. The method for manufacturing a quasi-two-dimensional blue LED device according to claim 2, wherein in the step 2, the metal nanoclusters are one of oil-soluble gold nanoclusters, oil-soluble silver nanoclusters, and oil-soluble copper nanoclusters in the mixed material of the metal nanoclusters and the conductive polymer.

4. The method for manufacturing a quasi-two-dimensional blue light LED device according to claim 3, wherein in the step 2, the metal nanoclusters in the mixed material of the metal nanoclusters and the conductive polymer account for 5% -55% of the mixed material.

5. The method of claim 4, wherein the metal nanoclusters are used to enhance hole conductivity.

6. The method of claim 4, wherein in the step 2, the organic reagent is one of DMSO, DMF, CB and m-xylene.

7. The method of claim 1, wherein in step 5, the electron transport material is one of TPBi/LiF, TPBi/Liq, Tmpypb/LiF, and Tmpypb/Liq.

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