CN109449313B - Method for preparing hole injection layer in organic light-emitting diode based on sol-gel method and constructed organic light-emitting diode - Google Patents
Method for preparing hole injection layer in organic light-emitting diode based on sol-gel method and constructed organic light-emitting diode Download PDFInfo
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- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K71/00—Manufacture or treatment specially adapted for the organic devices covered by this subclass
-
- H—ELECTRICITY
- H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
- H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
- H10K50/00—Organic light-emitting devices
- H10K50/10—OLEDs or polymer light-emitting diodes [PLED]
- H10K50/17—Carrier injection layers
Abstract
The invention relates to a method for preparing a hole injection layer in an organic light-emitting diode based on a sol-gel method and the organic light-emitting diode constructed by the method, which belong to the technical field of basic electric elementsxThe method has the advantages of simple equipment, simple synthesis process, easy operation and good repeatability, and the VO obtained by the method has the advantages of simple preparation process of the precursor solution and preparation process of the hole injection layerxThe precursor solution has the advantages of water solubility, wide concentration tolerance, stability, excellent film form and the like, and can be used for constructing high-performance visible light or ultraviolet organic light emitting diodes.
Description
Technical Field
The invention belongs to the technical field of basic electrical elements, and particularly relates to a method for preparing a hole injection layer in an organic light-emitting diode based on a sol-gel method and a constructed organic light-emitting diode.
Background
Organic electronic devices including Organic Light Emitting Diodes (OLEDs), organic solar cells, organic transistors and organic detectors have received much attention due to their superior performance, mass production, mechanical flexibility and slim portability. Interface engineering plays a key role in achieving multilayer structuring of organic electronic devices. For example, the ubiquitous energy level mismatch between Indium Tin Oxide (ITO) anodes and organics hinders carrier injection/extraction. The Hole Injection Layer (HIL) interposed between the ITO and the organic Hole Transport Layer (HTL) may effectively improve interface contact, reduce a hole injection barrier, thereby adjusting carrier balance and improving device performance.
In recent years, solution processing techniques have greatly facilitated low-cost and large-scale manufacturing of organic electronic products. Hole injection layers from conventionalThe vacuum thermal deposition process goes to solution-soluble processing. Two-dimensional materials (such as graphene oxide and carbon nitride) and PEDOT: PSS have been extensively studied as a popular HIL based on solution processing. Metal oxides such as WOx, MoOx, NiO, La2O3And VOxDue to their good surface work function, high chemical/thermal stability and special electronic properties, there is an increasing interest in the preparation of high performance HILs based on solution processes. Due to the Highest Occupied Molecular Orbital (HOMO) level and wide band gap of the ultraviolet organic light emitting material, the high-performance HIL has important significance for constructing a high-efficiency ultraviolet organic light emitting diode. The ultraviolet organic light emitting diode has a short wave emission function and has wide application prospect in the fields of excitation light sources, high-density information storage, chemical sensors and the like.
As noted above, solution-treated metal oxides have advantages not comparable to other candidates. Vanadium oxide is reported to have hydrophobicity and a high work function tunable from 4.7 to 7.2eV, providing various forms of energy level matching. Currently, most reported solution-treated vanadium oxides are derived from ammonia solutions, isopropanol solutions and sodium metavanadate solutions. In contrast, with commercially available inexpensive V2O5The powder is a raw material for processing vanadium oxide by the synthetic solution, and is more beneficial to large-scale production. Will V2O5Dissolving the powder in water or ammonia solvent is a simple method for preparing solution treated vanadium oxide. However, V2O5The solubility of the powder directly in water is very low, which greatly limits the vanadium concentration in the solution. Therefore, there is an urgent need for a more efficient solution processing method for preparing vanadium oxide to obtain high performance visible and uv organic light emitting diodes.
Disclosure of Invention
In view of the above, an object of the present invention is to provide a method for constructing a hole injection layer in an organic light emitting diode based on a sol-gel method; the second purpose is to provide an ultraviolet organic light-emitting diode containing a hole injection layer prepared by a sol-gel method; the third purpose is to provide a visible light organic light-emitting diode containing a hole injection layer prepared by a sol-gel method.
In order to achieve the purpose, the invention provides the following technical scheme:
1. a method for preparing a hole injection layer in an organic light emitting diode based on a sol-gel method comprises the following steps:
(1)VOxpreparation of precursor solution
Will V2O5Uniformly dispersing the powder in water, adding hydrochloric acid, and stirring until the color of the solution is changed into yellow brown; then adding hydrazine hydrate, and stirring until the color of the solution is changed from yellow brown to blue; finally, polyvinylpyrrolidone is added and stirred for more than 1.5h to prepare VOxPrecursor liquid of the VOxWherein X is 2-2.5; the V is2O5The mol ratio of the powder, the hydrochloric acid and the hydrazine hydrate is 9-12:8-9.5:0.7-0.9, and the V is2O5The mass ratio of the powder to the polyvinylpyrrolidone is 1.5-2.5: 2-6;
(2) preparation of hole injection layer
VO prepared in the step (1)xAnd spin-coating the precursor on the anode layer, and then performing annealing treatment.
Preferably, in the step (1), the hydrochloric acid is added in a manner that: the hydrochloric acid is averagely divided into two parts and then added into the solution for two times, and the time interval between the two times of addition is 5 to 20 seconds.
Preferably, in the step (1), the hydrazine hydrate is added in a manner that: the hydrazine hydrate is divided into two parts on average, the first part of hydrazine hydrate is added firstly, the mixture is stirred until the color of the solution is changed from yellow brown to blue, and then the second part of hydrazine hydrate is added.
Preferably, in step (1), the stirring temperature is 50-70 ℃.
Preferably, in the step (2), the speed of the spin coating is 3000-.
Preferably, in the step (2), the annealing treatment is annealing at 400 ℃ of 280 ℃ to 30 min.
Preferably, in step (1), V is2O5The molar ratio of the powder, the hydrochloric acid and the hydrazine hydrate is 11:8.4:0.8, and the V is2O5Masses of powder and polyvinylpyrrolidoneThe quantity ratio is 2: 3.
2. An ultraviolet organic light emitting diode containing the hole injection layer prepared by the method.
3. The visible light organic light-emitting diode containing the hole injection layer prepared by the method.
The invention has the beneficial effects that: the invention provides a method for preparing a hole injection layer in an organic light-emitting diode based on a sol-gel method and the prepared organic light-emitting diode. The hydrochloric acid and the hydrazine hydrate are uniformly divided into two parts and are respectively added twice, so that the reaction rate is favorably controlled, and the experimental phenomenon in the material synthesis process is conveniently observed; secondly, the violent reaction caused by the excessively fast addition of the raw materials is prevented, the solution overflow caused by the violent reaction is effectively avoided, and the safety of the experimental process is ensured. The addition mode can be used for facilitating experimental operation, optimizing experimental details and finally achieving the purpose of optimizing material performance. After the interaction of hydrochloric acid and hydrazine hydrate, the finally prepared hole injection layer has special electronic performance, and is beneficial to regulating and controlling hole injection/extraction in an organic electronic device, so that the hole injection capability is improved. In addition, the addition mode of hydrochloric acid and hydrazine hydrate is optimized, the consumption of polyvinylpyrrolidone is limited, the cohesiveness of the vanadium oxide precursor solution is reduced, the finally prepared hole injection layer has a better appearance, the anode can be better modified, a matched energy level is formed between the anode and the organic layer, the hole injection barrier is further reduced, and the hole injection capability is improved. The method has the advantages of simple equipment, simple synthesis process, easy operation and good repeatability. The vanadium oxide precursor solution obtained by the method has the advantages of water solubility, wide concentration tolerance, stability, excellent film form and the like, and can be used for constructing high-performance visible light and ultraviolet organic light-emitting diodes.
Drawings
In order to make the object, technical scheme and beneficial effect of the invention more clear, the invention provides the following drawings for explanation:
FIG. 1 is an Atomic Force Microscope (AFM) analysis of the ITO anode layer, HIL2 and HIL4 of example 4; (AFM for ITO anode layer, AFM for HIL4, and AFM for HIL 2)
FIG. 2 is an X-ray photoelectron spectroscopy analysis chart of HIL2 and HIL4 in example 4; (core spectra of V2 p for HIL2 and HIL4 for a and b, respectively, and C1 s for HIL2 and HIL4 for C and d, respectively)
FIG. 3 is a chart of UV-VIS absorption spectrum analysis of HIL2 and HIL4 in example 4;
FIG. 4 is a graph showing current-voltage (I-V) characteristics and impedance spectrum analysis of each of the single hole devices of example 5; (a is an I-V diagram of each single-hole device, b is an impedance-voltage (Z-V) diagram of each single-hole device, and c is a phase angle-voltage diagram of each single-hole device
FIG. d is a capacitance-voltage (C-V) diagram of each single hole device
FIG. 5 is a graph showing the performance test of each visible light OLED in example 6; (a is a graph of luminous efficiency versus current density for each diode, b is a graph of power efficiency versus current density for each diode, c is a graph of current density versus voltage for each diode, and d is a graph of luminance versus voltage for each diode)
FIG. 6 is a graph showing the performance test of each UV OLED in example 7; (a is an irradiance-voltage curve graph of each diode, b is an external quantum efficiency-current density curve graph of each diode, c is a normalized electroluminescence spectrogram of each diode under different voltages (6-14V), and d is a normalized irradiance-working time curve graph of each diode)
FIG. 7 shows VO prepared by conventional aqueous solution processxPrecursor solution and VO prepared in example 1xA forerunner liquid performance stability map; (a is VO prepared in example 1xThe precursor solution is kept stand and stored for 4 months and 9 months, and b is VO prepared by the traditional aqueous solution processxState diagram of precursor liquid after standing and storing for 2 months
FIG. 8 is a diagram showing the preparation of VO in the present inventionxA precursor liquid flow chart.
Detailed Description
The preferred embodiments of the present invention will be described in detail below.
In each of the embodiments described herein, the first,
the ITO is indium tin oxide;
NPB is N, N '-diphenyl-N, N' - (1-naphthyl) -1,1 '-biphenyl-4, 4' -diamine;
CBP is 4,4' -bis (9-carbazole) biphenyl;
Alq3is tris (8-hydroxy-quinoline);
TAZ is 3- (biphenyl-4-yl) -5- (4-tert-butylphenyl) -4-phenyl-4H-1, 2, 4-triazole;
BPhen is 4, 7-diphenyl-1, 10-phenanthroline;
LiF is lithium fluoride;
al is aluminum.
In each example, current density-voltage-luminance (J-V-L) and spectral characteristics were measured using a test system consisting of a gishy source meter, a luminance meter, and a spectrometer. Photoluminescence (PL) spectra were measured using a spectrofluorimeter. The membrane morphology was characterized using atomic force microscopy. X-ray/ultraviolet photoelectron spectroscopy (XPS/UPS) analysis was performed using a photoelectron spectrometer. Impedance spectra were measured using a precision impedance analyzer. The absorption spectrum of the film was analyzed using an ultraviolet-visible spectrophotometer.
Example 1
VOxPreparation of precursor solution
According to the preparation scheme shown in FIG. 8, V2O5Uniformly dispersing the powder in water, taking hydrochloric acid, averagely dividing the hydrochloric acid into two parts, adding the two parts twice, wherein the time interval between the two parts is 10s, and stirring at 65 ℃ until the color of the solution is changed into yellow brown; then taking hydrazine hydrate, averagely dividing the hydrazine hydrate into two parts, adding the two parts for two times, firstly adding the first part of hydrazine hydrate, stirring at 65 ℃ until the color of the solution is changed from yellow brown to blue, and then adding the second part of hydrazine hydrate; finally, polyvinylpyrrolidone is added and stirred for 2 hours at the temperature of 65 ℃ to prepare VOxA precursor solution of V2O5The mol ratio of the powder, the hydrochloric acid and the hydrazine hydrate is 11:8.4:0.8, V2O5The mass ratio of the powder to the polyvinylpyrrolidone is 2: 3.
Example 2
VOxPreparation of precursor solution
According to the preparation scheme shown in FIG. 8, V2O5Uniformly dispersing the powder in water, taking hydrochloric acid, averagely dividing the hydrochloric acid into two parts, adding the two parts for two times, wherein the time interval between the two times of adding is 5s, and stirring at 70 ℃ until the color of the solution is changed into yellow brown; then taking hydrazine hydrate, averagely dividing the hydrazine hydrate into two parts, adding the two parts for two times, firstly adding the first part of hydrazine hydrate, stirring at 70 ℃ until the color of the solution is changed from yellow brown to blue, and then adding the second part of hydrazine hydrate; finally, polyvinylpyrrolidone is added and stirred for 2.5 hours at the temperature of 70 ℃ to prepare VOxA precursor solution of V2O5The molar ratio of the powder, the hydrochloric acid and the hydrazine hydrate is 9:9.5:0.9, V2O5The mass ratio of the powder to the polyvinylpyrrolidone was 1.5: 6.
Example 3
VOxPreparation of precursor solution
According to the preparation scheme shown in FIG. 8, V2O5Uniformly dispersing the powder in water, taking hydrochloric acid, equally dividing the hydrochloric acid into two parts, adding the two parts twice, wherein the time interval between the two parts is 20s, and stirring at 50 ℃ until the color of the solution is changed into yellow brown; then taking hydrazine hydrate, averagely dividing the hydrazine hydrate into two parts, adding the two parts for two times, firstly adding the first part of hydrazine hydrate, stirring at 50 ℃ until the color of the solution is changed from yellow brown to blue, and then adding the second part of hydrazine hydrate; finally adding polyvinylpyrrolidone, stirring for 3h at 50 ℃ to prepare VOxA precursor solution of V2O5The molar ratio of the powder, the hydrochloric acid and the hydrazine hydrate is 12:8:0.7, V2O5The mass ratio of the powder to the polyvinylpyrrolidone was 2.5: 2.
Example 4
Method for preparing cavity injection layer in organic light-emitting diode based on sol-gel method
Preparation of hole injection layer
VO prepared in example 1xThe precursor solutions are respectively diluted into VOxThe three solutions with the concentration of 2.0mg/mL, 1.6mg/mL and 1.0mg/mL are respectively coated on the ITO anode layer in a spin coating mode at the spin coating speedThe temperature is 5000rpm, the spin coating time is 60s, and finally the annealing is carried out for 20min at 400 ℃, and the annealing is sequentially named as HIL1, HIL2 and HIL 3.
Simultaneously, evaporating a layer of VO with the thickness of 1nm on the ITO anode layer by a vacuum thermal deposition processxLayer, named HIL 4.
The surface morphology of the ITO anode layer, HIL2 and HIL4 is shown in fig. 1, where a in fig. 1 is an AFM image of the ITO anode layer, b in fig. 1 is an AFM image of HIL4, and c in fig. 1 is an AFM image of HIL 2. As can be seen from fig. 1, the ITO anode layer surface showed distinct grains, grain boundaries and some pinholes, the root mean square roughness was 0.998nm, some pinholes were filled on the HIL4 surface, the surface waviness was weakened, and the root mean square roughness was 0.860 nm. The surface morphology of HIL2 was significantly improved, the existing pinholes and grain boundaries were more fully filled, the film coverage was more uniform, and the root mean square roughness was 0.249 nm. The method provided by the invention is fully shown to be capable of preparing a uniform vanadium oxide film, has a good coverage effect on an ITO anode layer, and ensures the flatness of the prepared hole injection layer.
The X-ray photoelectron spectroscopy analysis of HIL2 and HIL4 is shown in fig. 2, in which a and b in fig. 2 are V2 p core spectra of HIL2 and HIL4, respectively, and C and d in fig. 2 are C1 s spectra of HIL2 and HIL4, respectively. From a and b in FIG. 2, VO in HIL2 can be calculatedxX of 2.43, VO in HIL4x2.46, both vanadium oxides exhibit slight non-stoichiometric and special electronic properties that help to regulate hole injection/extraction in organic electronic devices. The value of X indicates the oxygen content, the smaller the value of X, the larger the oxygen defect, and the presence of the oxygen defect provides a channel for the transport of holes, so the larger the oxygen defect, the more channels are provided for the transport of holes. As can be seen from C and d in fig. 2, the C1 s spectrum of HIL4 has only a single peak at 284.8eV, while the C1 s spectrum of HIL2 has two peaks at 286.4eV and 288.5eV, indicating that-C-bond and C ═ O bond are also present in HIL 2.
The ultraviolet-visible light absorption spectrum analysis of HIL2 and HIL4 is shown in fig. 3, and it can be seen from fig. 3 that both HIL2 and HIL4 have very low absorbance in the range of 300-1100nm, indicating that the light loss through HIL2 and HIL4 is very small.
Example 5
Verification of hole injection capability of hole injection layer in organic light-emitting diode prepared based on sol-gel method
Based on example 4, a single-hole device with the following structure was constructed, and each single-hole device was analyzed by I-V characteristics and impedance spectroscopy, respectively, and the analysis results are shown in fig. 4, wherein a in fig. 4 is an I-V diagram of each single-hole device, b in fig. 4 is an impedance-voltage (Z-V) diagram of each single-hole device, and c in fig. 4 is a phase angle-voltage (a-V) diagram of each single-hole device
In the figure, d in fig. 4 is a capacitance-voltage (C-V) diagram of each hole-only device.
The structure of each single-hole device is as follows:
device H1:ITO/HIL1/NPB/Al
Device H2:ITO/HIL2/NPB/Al
Device H3:ITO/HIL3/NPB/Al
Device H4:ITO/HIL4/NPB/Al
Device H0:ITO/NPB/Al
As can be seen from a in FIG. 4, the device H is operated at the same voltage2Shows the highest current, followed in turn by device H4Device H1Device H3Device H0HIL2 was shown to have the strongest hole injection capability.
As can be seen from B and c in FIG. 4, each device exhibited 10 at low voltage (less than 1.5V)5Omega has high impedance, phase angle of about-90 deg., and is in insulation state. As the voltage increases, the impedance decreases rapidly and the corresponding phase angle deviates from-90 ° and approaches 0 °, which illustrates the transition of the devices from the insulating state to the semiconductor state. Wherein the device H2Exhibits the lowest transition voltage, followed in turn by device H4Device H1Device H3Device H0HIL2 was shown to have the strongest hole injection capability.
As can be seen from d in FIG. 4, almost the same initial value of capacitance is observed at low voltage for each hole-only device, and the initial value of capacitance gradually increases with the voltageAt an increase, the capacitance gradually increases and peaks (as indicated by the arrows in the figure) due to charge accumulation. Voltage pressing device H corresponding to capacitor peak value2<Device H4<Device H1<Device H3<Device H0The hole injection capability gradually decreases in the same sequence, and the device H2 has the lowest voltage, indicating that HIL2 has the strongest hole injection capability.
Example 6
The visible light organic light emitting diode having the following structure was constructed based on example 4, and the maximum luminous efficiency, the maximum power efficiency, the luminance at 9V, and the luminance of 1000cd/m of each diode were respectively tested2The voltage at that time, the test results are shown in fig. 5 and table 1, wherein a in fig. 5 is a graph of luminous efficiency versus current density of each diode, b in fig. 5 is a graph of power efficiency versus current density of each diode, c in fig. 5 is a graph of current density versus voltage of each diode, and d in fig. 5 is a graph of luminance versus voltage of each diode.
The structure of each visible light organic light emitting diode is as follows:
visible light OLED1:ITO/HIL1/NPB/Alq3/BPhen/LiF/Al
Visible light OLED2:ITO/HIL2/NPB/Alq3/BPhen/LiF/Al
Visible light OLED3:ITO/HIL3/NPB/Alq3/BPhen/LiF/Al
Visible light OLED4:ITO/HIL4/NPB/Alq3/BPhen/LiF/Al
Visible light OLED0:ITO/NPB/Alq3/BPhen/LiF/Al
In each of the above visible light organic light emitting diodes, ITO is an anode layer; HIL1, HIL2, HIL3, and HIL4 are all hole injection layers; NPB is a hole transport layer with the thickness of 50 nm; alq3Is a light-emitting layer with a thickness of 60 nm; BPhen is an electron transport layer with the thickness of 30 nm; LiF is an electron injection layer with the thickness of 0.5 nm; al is a cathode layer and has a thickness of 100 nm.
TABLE 1
As can be seen from Table 1 and FIG. 5, visible light OLED1Visible light OLED2Visible light OLED3And visible light OLED4Has better performance than that of visible light OLED0. Wherein, the visible light OLED2The maximum luminous efficiency is 6.3cd/A, the maximum power efficiency is 3.2lm/W, and the performance is better than that of a visible light OLED H4The maximum luminous efficiency (5.6cd/A) and the maximum power efficiency (2.7lm/W) are respectively improved by 12.5 percent and 18.5 percent. Visible light OLED2The hole injection capability of the medium HIL2 is strongest, the driving voltage is reduced, the carrier balance is promoted, and the finally prepared visible light organic light emitting diode has higher brightness and efficiency.
Example 7
Ultraviolet organic light emitting diodes having the following structures were constructed based on example 4, and the irradiance, external quantum efficiency, and electroluminescence spectrum of each diode were separately tested, and the test results are shown in fig. 6 and table 2. Wherein a in fig. 6 is a graph of irradiance-voltage of each diode, b in fig. 6 is a graph of external quantum efficiency-current density of each diode, c in fig. 6 is a graph of normalized electroluminescence spectrum of each diode under different voltages (6-14V), and d in fig. 6 is a graph of normalized irradiance and working time of each diode.
The structure of each ultraviolet organic light emitting diode is as follows:
ultraviolet OLED2:ITO/HIL2/CBP/TAZ/BPhen/LiF/Al
Ultraviolet OLED4:ITO/HIL4/CBP/TAZ/BPhen/LiF/Al
In each ultraviolet organic light emitting diode, ITO is taken as an anode layer; HIL2 and HIL4 are both hole injection layers; CBP is a hole transport layer with the thickness of 30 nm; TAZ is a luminescent layer with the thickness of 20 nm; BPhen is an electron transport layer with the thickness of 80 nm; LiF is an electron injection layer with the thickness of 2 nm; al is a cathode layer and has a thickness of 100 nm.
TABLE 2
As can be seen from graph a in FIG. 6 and Table 2, the UV OLED is operated at the same voltage2Maximum irradiance of 15.3mW/cm2@15.5V, and ultraviolet OLED4Maximum irradiance of 11.9mW/cm2@14.5V, UV OLED2Relatively ultraviolet OLED4Showing a higher irradiance.
As can be seen from graph b in FIG. 6 and Table 2, the UV OLED2Has a maximum quantum efficiency of 2.92%, while ultraviolet OLEDs4The maximum quantum efficiency of the quantum well is 2.32%, and the former is enhanced by 25.9% compared with the latter. Although uv organic light emitting diodes using multilayer stacked HILs or composite doped HILs yield an external quantum efficiency of about 4%, the external quantum efficiency of most uv organic light emitting diodes (wavelength less than 400nm) reported so far does not exceed 2%. UV OLEDs prepared using a single HIL layer in the present invention are superior to such devices. Its excellent properties are derived from the strong hole injection capability of the HIL prepared by the method of the present invention.
As can be seen from graph c in FIG. 6 and Table 2, the UV OLED2The electroluminescent peak of the organic electroluminescent device is 379nm, the half-peak width of the organic electroluminescent device is 40nm, and the ultraviolet OLED4The electroluminescent peak of the ultraviolet OLED is 380nm, the half-peak width is 44nm2Has narrower half-peak width, and shows that the purity of the emitted ultraviolet light is better.
Testing of non-encapsulated UV OLEDs separately at the same voltage and ambient conditions2And ultraviolet OLED4The lifetime of (A) is shown in graph d of FIG. 6, and it can be seen from graph d of FIG. 6 that the ultraviolet OLED4The electroluminescence intensity after 2 minutes of operation had dropped to 5% of the initial value, while the UV OLED had2Is that the electroluminescence intensity decreased to 5% of the initial value after 5 minutes of operation, indicating that HIL2 improved the lifetime of the uv organic light emitting diode.
Example 8
Testing VO prepared in the present inventionxStability of precursor solution
Preparation of VO by conventional aqueous solution processxThe precursor solution specifically comprises: mixing high-purity V2O5Dissolving the powder (99.99%) in deionized water directly, and performing ultrasonic treatmentAfter stirring for a further 4 hours for 30 minutes, it was left to stand at room temperature for 24 hours, and then the supernatant was taken and filtered through a 0.22 μm filter. VO with the concentration of 0.3mg/mL is preparedxSolution, which after storage at rest for 2 months, appeared to precipitate (as shown in b-diagram in fig. 7). And VO prepared in example 1 was addedxThe precursor solution was left to stand for 4 months and 9 months without precipitation (as shown in a in FIG. 7), which is sufficient to illustrate VO prepared by the method of the present inventionxThe precursor solution has good stability.
Finally, it is noted that the above-mentioned preferred embodiments illustrate rather than limit the invention, and that, although the invention has been described in detail with reference to the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the scope of the invention as defined by the appended claims.
Claims (7)
1. A method for preparing a hole injection layer in an organic light-emitting diode based on a sol-gel method is characterized by comprising the following steps:
(1)VOxpreparation of precursor solution
Will V2O5Uniformly dispersing the powder in water, adding hydrochloric acid, and stirring until the color of the solution is changed into yellow brown; then adding hydrazine hydrate, and stirring until the color of the solution is changed from yellow brown to blue; finally, polyvinylpyrrolidone is added and stirred for more than 1.5h to prepare VOxPrecursor liquid of the VOxWherein X is 2-2.5; the V is2O5The mol ratio of the powder, the hydrochloric acid and the hydrazine hydrate is 9-12:8-9.5:0.7-0.9, and the V is2O5The mass ratio of the powder to the polyvinylpyrrolidone is 1.5-2.5: 2-6;
(2) preparation of hole injection layer
VO prepared in the step (1)xSpin-coating the precursor on the anode layer, and then performing annealing treatment;
in the step (1), the hydrochloric acid is added in the following manner: the hydrochloric acid is averagely divided into two parts and then added for two times, and the time interval between the two times of addition is 5-20 s;
in the step (1), the hydrazine hydrate is added in the following manner: the hydrazine hydrate is divided into two parts on average, the first part of hydrazine hydrate is added firstly, the mixture is stirred until the color of the solution is changed from yellow brown to blue, and then the second part of hydrazine hydrate is added.
2. The method according to claim 1, wherein the stirring temperature in step (1) is 50-70 ℃.
3. The method as claimed in claim 1, wherein in step (2), the spin speed is 3000-8000rpm, and the spin time is 60 s.
4. The method as claimed in claim 1, wherein in the step (2), the annealing treatment is annealing at 400 ℃ for 15-30 min.
5. The method according to any one of claims 1 to 4, wherein in step (1), said V is2O5The molar ratio of the powder, the hydrochloric acid and the hydrazine hydrate is 11:8.4:0.8, and the V is2O5The mass ratio of the powder to the polyvinylpyrrolidone is 2: 3.
6. An ultraviolet organic light emitting diode comprising a hole injection layer prepared by the method of any one of claims 1 to 4.
7. A visible light organic light emitting diode comprising a hole injection layer prepared by the method of any one of claims 1 to 4.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101760735A (en) * | 2008-12-31 | 2010-06-30 | 中国科学院上海硅酸盐研究所 | Vanadium dioxide precursor liquid and method for preparing thin-film material by using the same |
| CN104030357A (en) * | 2014-06-27 | 2014-09-10 | 武汉工程大学 | Method for preparing vanadium dioxide thin films by using organic sol-gel |
| CN105140394A (en) * | 2015-07-06 | 2015-12-09 | Tcl集团股份有限公司 | Hole injection layer manufacturing method, hole injection layer and QLED device |
| CN105198231A (en) * | 2014-05-30 | 2015-12-30 | 武汉理工大学 | Inorganic sol-gel preparation method of vanadium dioxide film |
| CN205542905U (en) * | 2016-01-29 | 2016-08-31 | 桂林电子科技大学 | Ultraviolet organic light emitting device |
| CN106129262A (en) * | 2016-07-11 | 2016-11-16 | 电子科技大学中山学院 | Ultraviolet organic light-emitting device with double hole injection layers and preparation method thereof |
-
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101760735A (en) * | 2008-12-31 | 2010-06-30 | 中国科学院上海硅酸盐研究所 | Vanadium dioxide precursor liquid and method for preparing thin-film material by using the same |
| CN105198231A (en) * | 2014-05-30 | 2015-12-30 | 武汉理工大学 | Inorganic sol-gel preparation method of vanadium dioxide film |
| CN104030357A (en) * | 2014-06-27 | 2014-09-10 | 武汉工程大学 | Method for preparing vanadium dioxide thin films by using organic sol-gel |
| CN105140394A (en) * | 2015-07-06 | 2015-12-09 | Tcl集团股份有限公司 | Hole injection layer manufacturing method, hole injection layer and QLED device |
| CN205542905U (en) * | 2016-01-29 | 2016-08-31 | 桂林电子科技大学 | Ultraviolet organic light emitting device |
| CN106129262A (en) * | 2016-07-11 | 2016-11-16 | 电子科技大学中山学院 | Ultraviolet organic light-emitting device with double hole injection layers and preparation method thereof |
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