KR20240015132A - Organic light-emitting transistor with perovskite quantum dots - Google Patents

Abstract

An organic light emitting transistor according to an embodiment of the present invention includes a gate electrode; an insulating layer disposed on the gate electrode; an n-type metal oxide layer disposed on a portion of the insulating layer; An organic light-emitting layer including perovskite quantum dots represented by the following formula (1) disposed on the insulating layer and covering the n-type metal oxide layer; a p-type first metal oxide layer disposed on a portion of the organic emission layer; a p-type second metal oxide layer disposed on a portion of the organic emission layer and spaced apart from the p-type first metal oxide layer; a source electrode disposed on the p-type first metal oxide layer; and a drain electrode disposed on the p-type second metal oxide layer.
[Formula 1]
ABX _{3- n}
(In Formula 1, A is at least one selected from organic ammonium, organic amidinium, and alkali metal, and B is a divalent transition metal, rare earth metal, alkaline earth metal, Pb, Sn, Ge, Ga, In , Al, Sb, Bi, Po and at least one selected from organic materials, and X and It is at least one selected from F, Cl, Br and I, and 0 ≤ n ≤ 3.)

Description

Organic light-emitting transistor with perovskite quantum dots}

The present invention relates to an organic light-emitting transistor to which perovskite quantum dots are applied, perovskite quantum dots for application to an organic light-emitting transistor, and a method of manufacturing the same.

Organic light-emitting transistors are new optoelectronic devices that can combine the light-emitting characteristics of organic light-emitting diodes and the current modulation function of organic thin-film transistors. This has the advantage of simplifying design in the fields of smart display technology and organic lasers. However, there are still problems to overcome, such as low carrier mobility, low brightness, high operating voltage, low external quantum efficiency (EQE) at high current density, and low stability.

In addition, in the case of the previously reported synthesis process of organometallic halide perovskite quantum dots, polar solvents, ligands, and unreacted precursor materials remain in the final synthesized quantum dot solution, which acts as a factor impeding the stability of the quantum dot solution and causes the quantum dots to deteriorate. There are limitations that degrade performance.

International Publication WO 2016/072809 (2016.05.12)

The present invention seeks to realize optimal performance of organic light-emitting transistors by applying perovskite quantum dots as a light-emitting layer material for organic light-emitting transistors.

In addition, the present invention applies perovskite quantum dots by a ligand separation reprecipitation manufacturing process that can be manufactured at room temperature conditions, rather than by the existing synthesis method of perovskite quantum dots, as a light-emitting layer material for organic light-emitting transistors. We want to solve the problem.

In addition, the present invention provides an organic light-emitting transistor with significantly improved electron mobility, luminescence, and external quantum efficiency by applying perovskite quantum dots to maintain the characteristics of the quantum dot even when thinning is applied to the organic light-emitting transistor. I want to do it.

In addition, the present invention improves stability and dispersibility by efficiently removing residual substances such as polar solvents, ligands, and unreacted precursors through a ligand separation and reprecipitation manufacturing process, and produces a perovskite having SCLC (space charge limited current) driving characteristics. The aim is to provide an organic light-emitting transistor using skyte quantum dots.

In order to solve the above problems,

An organic light emitting transistor according to an embodiment of the present invention includes a gate electrode; an insulating layer disposed on the gate electrode; an n-type metal oxide layer disposed on a portion of the insulating layer; An organic light-emitting layer including perovskite quantum dots disposed on the insulating layer and covering the n-type metal oxide layer; a p-type first metal oxide layer disposed on a portion of the organic emission layer; a p-type second metal oxide layer disposed on a portion of the organic emission layer and spaced apart from the p-type first metal oxide layer; a source electrode disposed on the p-type first metal oxide layer; and a drain electrode disposed on the p-type second metal oxide layer.

The perovskite quantum dots are represented by the following formula (1).

[Formula 1]

ABX _{3- n}

(In Formula 1, A is at least one selected from organic ammonium, organic amidinium, and alkali metal, and B is a divalent transition metal, rare earth metal, alkaline earth metal, Pb, Sn, Ge, Ga, In , Al, Sb, Bi, Po and at least one selected from organic materials, and X and It is at least one selected from F, Cl, Br and I, and 0 ≤ n ≤ 3.)

In addition, the perovskite quantum dots included in the organic light-emitting transistor organic light-emitting layer include: preparing a precursor solution by stirring a compound including a first halogen compound, a second halogen compound, and a first ligand in a first solvent; Preparing a non-solvent by stirring a compound containing a second ligand different from the first ligand in a second solvent; Stirring the precursor solution and the non-solvent; and centrifuging the stirred solution to obtain a precipitate.

The present invention implements optimal performance of the organic light-emitting transistor by applying perovskite quantum dots as the light-emitting layer material of the organic light-emitting transistor.

In addition, the present invention applies perovskite quantum dots obtained through a ligand separation reprecipitation manufacturing process that can be manufactured at room temperature conditions, rather than the existing synthesis method of perovskite quantum dots, as a light-emitting layer material for organic light-emitting transistors. Solve the problem.

In addition, the present invention provides an organic light-emitting transistor with significantly improved electron mobility, luminescence, and external quantum efficiency by applying perovskite quantum dots to maintain the characteristics of the quantum dot even when thinning is applied to the organic light-emitting transistor. do.

In addition, the present invention improves stability and dispersibility by efficiently removing residual substances such as polar solvents, ligands, and unreacted precursors through a ligand separation and reprecipitation manufacturing process, and produces a perovskite having SCLC (space charge limited current) driving characteristics. An organic light-emitting transistor using skyte quantum dots is provided.

Figure 1 is a schematic diagram of a transistor to which perovskite quantum dots are applied according to an embodiment of the present invention and an image of the emission of quantum dots.
Figure 2 is a schematic diagram of the perovskite quantum dot synthesis process according to an embodiment of the present invention.
Figure 3 is a graph showing the electrical mobility and brightness characteristics of a transistor to which perovskite quantum dots are applied according to an embodiment of the present invention.
Figure 4 is a graph showing (a) photoluminescence spectrum and (b) absorbance of perovskite quantum dots according to Examples and Comparative Examples of the present invention.
Figure 5 shows an ultraviolet irradiated luminescent film of perovskite quantum dots according to Examples and Comparative Examples of the present invention.
Figure 6 is an image taken with a transmission electron microscope of perovskite quantum dots according to an embodiment of the present invention.
Figure 7 is a JV curve (SCLC) using a log-log scale according to examples and comparative examples of the present invention.

Hereinafter, the present invention will be described in more detail through examples. Since these examples are merely for illustrating the present invention, the scope of the present invention is not to be construed as limited by these examples.

Expressions such as “comprising” used in this specification are understood as open-ended terms that imply the possibility of including other embodiments, unless specifically stated otherwise in the phrase or sentence containing the expression. It has to be.

As used herein, “preferred” and “preferably” refer to embodiments of the invention that may provide certain advantages under certain circumstances. However, under the same or different circumstances, other embodiments may also be preferred. Additionally, mention of one or more preferred embodiments does not mean that other embodiments are not useful, nor is it intended to exclude other embodiments from the scope of the invention.

An organic light emitting transistor according to an embodiment of the present invention includes a gate electrode; an insulating layer disposed on the gate electrode; an n-type metal oxide layer disposed on a portion of the insulating layer; An organic light-emitting layer including perovskite quantum dots disposed on the insulating layer and covering the n-type metal oxide layer; a p-type first metal oxide layer disposed on a portion of the organic emission layer; a p-type second metal oxide layer disposed on a portion of the organic emission layer and spaced apart from the p-type first metal oxide layer; a source electrode disposed on the p-type first metal oxide layer; and a drain electrode disposed on the p-type second metal oxide layer.

The perovskite quantum dots are represented by the following formula (1).

[Formula 1]

ABX _{3- n}

(In Formula 1, A is at least one selected from organic ammonium, organic amidinium, and alkali metal, and B is a divalent transition metal, rare earth metal, alkaline earth metal, Pb, Sn, Ge, Ga, In , Al, Sb, Bi, Po and at least one selected from organic materials, and X and It is at least one selected from F, Cl, Br and I, and 0 ≤ n ≤ 3.)

Organic light-emitting transistors have the problem of increased driving voltage because the charge carrier density of the organic semiconductor used as the light-emitting layer is significantly lower than that of inorganic materials. In particular, when the hole injection efficiency from the drain electrode is low, there is a disadvantage in that the luminous efficiency is significantly reduced due to charge carrier recombination.

In order to solve the above problem, the present invention applied perovskite quantum dots as an organic light-emitting layer.

As an example, in order to solve the above problem, perovskite quantum dots included in the organic light-emitting layer can be manufactured by separating different ligands in different solvents. Unlike existing perovskite quantum dot manufacturing methods, the present invention stably precipitates perovskite quantum dots, and residual substances such as unreacted precursors and polar solvents can be efficiently removed through a process of removing the supernatant.

As an example, the method for producing perovskite quantum dots includes preparing a precursor solution by stirring a compound including a first halogen compound, a second halogen compound, and a first ligand in a first solvent; Preparing a non-solvent by stirring a compound containing a second ligand different from the first ligand in a second solvent; Stirring the precursor solution and the non-solvent; and obtaining a precipitate by first centrifuging the stirred solution (FIG. 2).

First, a step of preparing a precursor solution may be performed by stirring a compound including the first halogen compound, the second halogen compound, and the first ligand in a first solvent.

As an example, in the above step, the first halogen particle is a reactant for synthesizing perovskite nanoparticles represented by Formula 1 and may be represented by AX. As an example, the first halogen particle may be one or more selected from organic ammonium halide, organic amidinium halide, and alkali metal halide.

As an example, the second halogen particle is a reactant for synthesizing perovskite nanoparticles represented by Chemical Formula 1 and may be represented by BX ₂ , and may be PbBr 2 , SnCl ₂ , or GeCl ₂ as examples.

As an example, the first solvent may be a polar solvent. The first solvent may be a solvent in which the first halogen compound, the second halogen compound, and the first ligand can be dissolved. As an example, the first solvent may include dimethylformamide (DMF), dimethyl sulfoxide (DMSO), acetonitrile, formamide, ethanolamine, isopropyl alcohol, GBL, or mixtures thereof.

As an example, the first ligand may be independently selected from amine, carboxylic acid, silane, phosphine, phosphine oxide, phosphonic acid, phosphinic acid, and thiol, but is not particularly limited thereto. The particle size of the perovskite quantum dots produced can be controlled depending on the type and concentration of the first ligand.

As a more preferred example, the first ligand may be an amine. As an example, the first ligand may be an alkylamine, a C1-C20 alkylamine, or one or more selected from oleylamine, octylamine, hexadecylamine, octadecylamine, and trioctylamine. .

Additionally, as a more preferred example, the first ligand may be silane. When a silane ligand is used, silanization reaction occurs through a siloxane bond of Si-O-Si. At this time, the existing process had a problem in that a network structure was formed between the ligand and the particles during the silanization process, resulting in agglomeration between particles. However, through the ligand separation and reprecipitation process of the present invention, silica core-shell perovskite with improved solution dispersibility and quantum dots that efficiently implement RGB colors can be manufactured.

Additionally, as a more preferred example, the first ligand may be a silane ligand represented by the following formula (2).

[Formula 2]

(In Formula 2, R1 to R3 are each independently a C1-C6 alkyl group, a C1-C6 alkylene group, or a C1-C6 alkenyl group)

By using a ligand in which one methoxy or ethoxy group is substituted with an alkyl group (CH ₃ ), etc. in the previously reported silane ligands (3-Aminopropyl)trimethoxysilane (APTMS) or (3-Aminopropyl)triethoxysilane (APTES), The problem of cohesion between particles can be improved and the dispersibility of the solution can be further improved.

Silica core-shell perovskite quantum dots manufactured using the silane ligand represented by Formula 2 include a core layer of a perovskite structure; and a shell layer including a Si-0-Si bond, wherein the shell layer may have a structure in which a C1-C6 alkyl group, a C1-C6 alkenyl group, or a C1-C6 alkynyl group is bonded to a Si element.

Next, a step of preparing a non-solvent may be performed by stirring a compound containing a second ligand different from the first ligand in a second solvent.

In the above step, the second ligand is different from the first ligand and may be independently selected from amine, carboxylic acid, silane, phosphine, phosphine oxide, phosphonic acid, phosphinic acid, and thiol, but is specifically limited thereto. That is not the case.

Since the existing process reacts the ligands without separating them, there was a problem in that the stability of the quantum dot solution was impaired because the precipitation of quantum dots was not smooth through the co-ligand phenomenon in which the ligands act together. On the other hand, in one embodiment of the present invention, stable precipitation can be induced by separately adding different ligands to the first solvent and the second solvent and reacting them.

As a more preferred example, the second ligand may be oleic acid. Oleic acid acts on the precipitation and removal process of aggregated quantum dots to control the polarity of the nucleation environment and can be used as a stabilizer at the same time. In particular, when optimizing the amount of oleic acid added, oleic acid acts to inhibit aggregation of quantum dots, stabilize the solution, and induce precipitation rather than co-ligand. Dispersibility can be improved.

When the second ligand is oleic acid, the oleic acid may be included in an amount of 10 to 60% by volume, 15 to 50% by volume, or 20 to 40% by volume relative to the volume of the second solvent. As a preferred example, it may be included in 20 to 30% by volume. If the oleic acid is less than the above range, there may be a problem that it is difficult to precipitate the nanoparticles, and if it is above the above range, there may be a problem that the size distribution of the nanoparticles becomes wider. The present invention can produce stable perovskite quantum dots by adding a sufficient amount of oleic acid and optimizing the amount added.

The present invention has the effect of improving solution dispersibility by using a sufficient amount of oleic acid in the above range rather than acting as a co-ligand with the first ligand. That is, adding an optimized amount of oleic acid to the non-solvent can induce precipitation of perovskite quantum dots and improve the stability of the solution synthesized after centrifugation.

Additionally, as an example, the second solvent may be a non-polar solvent and may be a solvent in which the second ligand can be dissolved. As an example, it may include toluene, hexane, cyclohexane, chloroform, xylene, octane, chloroethylene, chlorobenzene, or mixtures thereof, but is not particularly limited thereto.

Next, a step of stirring the precursor solution and the non-solvent may be performed. When the precursor solution and the non-solvent are stirred, a perovskite quantum dot solution is formed and a specific color may develop.

Next, a step of first centrifuging the stirred solution to obtain a precipitate may be performed. In this step, the first centrifugation may be performed at 4000 to 10,000 rpm.

Next, after obtaining the precipitate containing the nanoparticles, a step of dispersing them in a third solvent may be further performed. The dispersion step is a step of obtaining a high-concentration dispersion by redispersing the precipitate in a third solvent. The third solvent may be a non-polar solvent that can stably disperse perovskite quantum dots, etc. in a colloidal state. While performing this stable redispersion step, residual precursors such as ligands and polar solvents can be removed, making it possible to manufacture nanoparticles with guaranteed stability as a colloidal solution. Since the production method according to the embodiment of the present invention does not undergo precipitation and purification processes using a polar solvent, solution stability can be secured.

Next, a second centrifugation step may be performed on the dispersed solution for further purification. The second centrifugation may be performed at a speed of 4000 to 10,000 rpm.

The perovskite quantum dots included as the organic light-emitting layer in the organic light-emitting transistor of the present invention have an average diameter of 1 to 20 nm, 1 to 10 nm, 1 to 5 nm, 2 to 20 nm, and 2 to 10 nm depending on the type, concentration, and halide type of the ligand. , or 2 to 5 nm Can be adjusted in size.

As a more preferred example, the average diameter of the perovskite quantum dots may be 3.30 to 4.50 nm.

Additionally, as an example, the crystal structure of the perovskite quantum dots is cubic, and the interplanar distance (d spacing) corresponding to the (002) crystal plane may be 2.50 to 3.20 Å.

Additionally, when analyzing the prepared perovskite nanoparticles using X-ray diffraction (XRD), peaks may be formed at (100), (110), (210), and (300).

In addition, when analyzing the prepared perovskite nanoparticles using X-ray diffraction (XRD), peaks may be formed at (110), (112), (200), (004), (220), and (310). .

In addition, when analyzing the prepared perovskite nanoparticles by can be formed.

Additionally, as an example, the perovskite quantum dots may have a full width at half maximum (FWHM) of 24.50 to 24.70 nm when analyzed by photoluminescence spectroscopy.

The analysis was performed using an X-ray spectrometer (Bruker AXS, New D8-Advance), with CuKα radiation.

Additionally, as an example, the perovskite quantum dots may have a photoluminescence quantum yield of 92.0%, or 92.5 or more.

Additionally, as an example, the perovskite quantum dots may have a core-shell structure.

Additionally, as an example, the perovskite quantum dots may be nanoparticles coated with another particle layer through a coating process.

Additionally, as an example, the perovskite nanoparticles may be doped nanoparticles in which A, B, and X are substituted with other elements.

The organic light emitting transistor according to an embodiment of the present invention may use SiO ₂ as the gate electrode, but is not particularly limited thereto.

As an example, the thickness of the gate electrode may be 40 to 80 nm.

The organic light emitting transistor according to an embodiment of the present invention may use SiO ₂ as the insulating layer, but is not particularly limited thereto.

As an example, the thickness of the insulating layer may be 50 to 200 nm, 70 to 150 nm, or 90 to 120 nm. Within the above range, the organic light emitting transistor of the present invention can achieve optimal performance.

The n-type metal oxide layer of the organic light emitting transistor according to an embodiment of the present invention can receive electrons from the source electrode and move the electrons to the drain electrode.

As a more preferred example, the n-type metal oxide layer may include Zinc-oxynitride (ZnON). This can further improve the light emission characteristics of an organic light-emitting transistor using perovskite as an organic light-emitting layer because it has high electron mobility, wide optical band gap, and high transmittance. In particular, due to the excellent electron mobility characteristics of ZnON, the decrease in electron injection efficiency can be minimized even if a p-type metal oxide semiconductor is located below the source electrode.

As an example, the n-type metal oxide layer may have a thickness of 30 to 50 nm.

At least one of the p-type first metal oxide layer and the p-type second metal oxide layer of the organic light emitting transistor according to an embodiment of the present invention may include molybdenum oxide (MoOx). Accordingly, the balance of electron injection efficiency from the source electrode and hole injection efficiency from the drain electrode can be further optimized.

As an example, the p-type first metal oxide layer and the p-type second metal oxide layer may be made of the same material.

As an example, the p-type first metal oxide layer and the p-type second metal oxide layer may have a thickness of 5 to 15 nm.

At least one of the source electrode and the drain electrode of the organic light emitting transistor according to an embodiment of the present invention may include gold (Au). In this case, the external quantum efficiency and luminous intensity of a light-emitting transistor using perovskite as an organic light-emitting layer can be significantly improved.

As an example, the thickness of the source electrode and the drain electrode may be 40 to 80 nm, or 50 to 70 nm. Within the above range, the organic light emitting transistor of the present invention can achieve optimal performance.

The organic light-emitting transistor according to an embodiment of the present invention can significantly improve electron mobility, luminescence, and external quantum efficiency by applying perovskite quantum dots manufactured by a ligand separation reprecipitation manufacturing process to the organic light-emitting transistor of the above structure. there is.

The organic light emitting transistor according to an embodiment of the present invention may have an electron mobility of 12.00 cm ² V ^-1 s ^-1 or more.

Additionally, the organic light emitting transistor according to an embodiment of the present invention may have a luminance of 1.40 × 10 ⁴ cd m ^-2 or more.

Additionally, the organic light emitting transistor according to an embodiment of the present invention may have an external quantum efficiency of 1.70% or more at a source-drain potential (V _SD ) of 40V.

Additionally, the brightness of the organic light emitting transistor according to an embodiment of the present invention may gradually decrease as V _G increases beyond 50V.

While an organic light-emitting transistor using a general organic light-emitting material as the light-emitting layer increases the amount of light emitted as V _G increases, the organic light-emitting transistor according to an embodiment of the present invention exhibits a characteristic of gradually decreasing as V _G increases beyond 50V. You can.

[Example 1]

PbBr ₂ (0.1 mmol), CH ₃ NH ₃ Br (0.1 mmol), and octylamine (15 μL) were prepared and stirred in 2 mL of DMF solvent to obtain a transparent precursor solution. Next, a non-solvent was prepared by stirring 1.7 mL of oleic acid in 5 mL of toluene. 2 ml of the precursor solution was added to the non-solvent and stirred vigorously. Next, the solution was centrifuged at 8000 rpm for 5 minutes to obtain a precipitate. The obtained precipitate contained quantum dots and large particles. Next, the precipitate was redispersed in 2 ml of toluene to obtain a high-concentration dispersion, and then centrifuged at a speed of 8000 rpm for 5 minutes for purification.

[Example 2] Preparation of silica core-shell CH ₃ NH ₃ PbBr ₃

The same procedure as Example 1 was performed, except that 3-Aminopropyl(diethoxy)methylsilane (APDEMS) (15 μL) was used instead of the octylamine ligand.

[Comparative example]

PbBr ₂ (0.2 mmol), CH ₃ NH ₃ Br (0.2 mmol), octylamine (10 μL), and oleic acid (500 μL) were dissolved in 5 mL of DMF solvent to obtain a transparent precursor solution. Next, 1 ml of the precursor solution was added to toluene and stirred vigorously, and yellow-green quantum dots were formed within 1 second. Next, the solution was centrifuged at 7000 rpm for 10 minutes and large particles were removed.

[Manufacturing example] Manufacture of transistor

A 100 nm thick insulating layer made of SiO ₂ material was formed on the p-doped silicon gate electrode, and a 40 nm thick patterned ZnON electron transport layer was formed on the insulating layer. The electron transport layer was formed by reactive magnetron sputtering through a Zn target in a reactive gas (Ar/N ₂ /O ₂ ) without heating, and then thermal annealing was performed in air at 300°C for 1 hour.

The perovskite quantum dot dispersions according to the examples and comparative examples were spin-coated on the electron transport layer to form a light-emitting layer at 2000 rmp for 60 seconds, and then coated on a hot plate at 90°C for 20 minutes in a glove box filled with N ₂ . Annealed.

A 10 nm thick MoOx layer oriented opposite to each other on the emitting layer was thermally evaporated using a shadow mask. Next, 60 nm thick Au source and drain electrodes with a channel length (L) of 50 μm and a width (W) of 1000 μm were formed by thermal evaporation.

[Experimental example]

The present invention investigated the electrical and optical properties in the p-channel and n-channel operating regions to investigate the operation mechanism of perovskite quantum dots according to embodiments of the present invention in organic light-emitting transistors.

It was confirmed that the perovskite quantum dots according to the examples of the present invention have optoelectronic properties such as high color purity (full width at half maximum: 24.59 nm) and excellent photoluminescence quantum yield (92.7%).

The organic light-emitting transistor according to an embodiment of the present invention has an electron mobility of 12.06 cm ² V ^-1 s ^-1 , luminescence of 1.41 × 10 ⁴ cd m ^-2 , and an external proton of 1.79% at a source-drain potential (V _SD ) of 40V. It was confirmed that it had efficiency (EQE).

Referring to Figure 1(a), in order to inject holes into the relatively deep balance band of the perovskite layer, a molybdenum oxide (MoOx) layer was inserted between the perovskite quantum dot light-emitting layer and the source-drain electrode. In addition, an Au electrode with a work function of 5.1 eV was used as the source-drain electrode, and the optimal energy mechanism operated by this was confirmed.

Figure 1 (b) shows the structure of an organic light-emitting transistor according to an embodiment of the present invention. Zinc-oxynitride (ZnON) film with high electron mobility was used as an electron transport layer, and perovskite quantum dots according to an embodiment of the present invention were used as an emitting material.

Figure 1(c) shows a photograph of quantum dots dispersed in a toluene solution. Quantum dots appear yellow under ambient light and emit bright green when irradiated with ultraviolet light at 365 nm. In this case, the PLQY of the quantum dots was measured at 92.7%. According to the TEM image in Figure 1(d), it can be confirmed that the average diameter of the quantum dots according to the embodiment of the present invention is 3.91 ± 0.56 nm. In addition, the interplanar distance (d spacing) corresponding to the (002) crystal plane of cubic perovskite was measured to be 2.98 Å.

Table 1 below shows performance values of organic light-emitting transistors according to examples of the present invention.

[Table 1]

Figure 2 shows a ligand separation reprecipitation process for producing perovskite quantum dots applied to an organic light-emitting transistor according to an embodiment of the present invention.

Referring to FIG. 3, it can be seen that the brightness of the organic light-emitting transistor according to the embodiment of the present invention decreases at high V _G.

Referring to Figure 4, the excellence of electron transport of the perovskite quantum dot introduction layer according to an embodiment of the present invention can be confirmed.

Referring to Figure 5, it can be seen that the excellent luminescence of the perovskite quantum dot-introduced layer according to an embodiment of the present invention.

Referring to Figure 6, the interplanar distance of perovskite quantum dots according to an embodiment of the present invention can be confirmed.

Referring to FIG. 7, the device using the quantum dots according to the comparative example of the present invention does not exhibit semiconductor properties due to the overall appearance of the ohmic region due to low stability, while the device using the perovskite quantum dots according to the present example has It was confirmed that it represents a space-charge limited current (SCLC) region. Therefore, it was confirmed that a more stable device can be implemented by applying the perovskite quantum dots according to this example.

Claims (5)

gate electrode;
an insulating layer disposed on the gate electrode;
an n-type metal oxide layer disposed on a portion of the insulating layer;
An organic light-emitting layer including perovskite quantum dots represented by the following formula (1) disposed on the insulating layer and covering the n-type metal oxide layer;
a p-type first metal oxide layer disposed on a portion of the organic emission layer;
a p-type second metal oxide layer disposed on a portion of the organic emission layer and spaced apart from the p-type first metal oxide layer;
a source electrode disposed on the p-type first metal oxide layer; and
It includes a drain electrode disposed on the p-type second metal oxide layer,
[Formula 1]
ABX _{3- n}
(In Formula 1, A is at least one selected from organic ammonium, organic amidinium, and alkali metal, and B is a divalent transition metal, rare earth metal, alkaline earth metal, Pb, Sn, Ge, Ga, In , Al, Sb, Bi, Po and at least one selected from organic materials, and X and It is at least one selected from F, Cl, Br and I, and 0 ≤ n ≤ 3.)
The perovskite quantum dots are,
Preparing a precursor solution by stirring a compound including a first halogen compound, a second halogen compound, and a first ligand in a first solvent;
Preparing a non-solvent by stirring a compound containing a second ligand different from the first ligand in a second solvent;
Stirring the precursor solution and the non-solvent; and
It is manufactured by a manufacturing method comprising: centrifuging the stirred solution to obtain a precipitate,
The first ligand is an amine,
The second ligand is oleic acid,
The average diameter of the perovskite quantum dots is 3.30 to 4.50 nm,
The crystal structure of perovskite quantum dots is cubic, and the interplanar distance (d spacing) corresponding to the (002) crystal plane is 2.50 to 3.20 Å,
The perovskite quantum dots have a full width at half maximum (FWHM) of 24.50 to 24.70 nm when analyzed by photoluminescence spectroscopy,
The perovskite quantum dots have a photoluminescence quantum yield of 92.0% or more, and
An organic light-emitting transistor whose brightness gradually decreases as VG increases beyond 50V.
According to claim 1,
The perovskite quantum dots have a core-shell structure,
Organic light emitting transistor.
According to claim 1,
The n-type metal oxide layer includes ZnON (Zinc-oxynitride),
Organic light emitting transistor.
According to claim 1,
At least one of the p-type first metal oxide layer and the p-type second metal oxide layer includes molybdenum oxide (MoOx),
Organic light emitting transistor.
According to claim 1,
At least one of the source electrode and the drain electrode includes gold (Au),
Organic light emitting transistor.