An optoelectronic device

Abstract

The present disclosure provides an optoelectronic device. A modification layer is added to the surface of the first electrode layer on the side away from the substrate. The presence of the modification layer can prevent the first electrode layer from directly contacting other film layers, and can play a role in slowing down the corrosion of the indium-containing oxide constituting the first electrode layer. Moreover, the indium ion capture groups contained in the modification layer can fix the indium ions released after the corrosion of the indium-containing oxide on the surface of the first electrode layer, preventing the indium ions from moving into the interior of the optoelectronic device, thereby increasing the lifespan of the optoelectronic device.

Description

Technical Field

[0001] The present disclosure relates to the field of display technologies, and particularly to an optoelectronic device. Background Art

[0002] In 1988, Bayer AG in Germany first synthesized a derivative of polythiophene, poly(3,4-ethylenedioxythiophene) (PEDOT). It uses 3,4-ethylenedioxythiophene (EDOT) as a monomer and has characteristics such as high conductivity and good environmental stability, which has attracted extensive interest from scientists. The insolubility of PEDOT itself limits its applications. Subsequently, doping with a water-soluble polyelectrolyte, polystyrene sulfonic acid (PSS), solved the processing problem of PEDOT, and the obtained PEDOT:PSS film has high conductivity, high mechanical strength, high visible light transmittance, and excellent stability, etc. Since then, the application fields of PEDOT have developed rapidly, especially new materials, new processes, new components, etc. developed based on PEDOT have been fully developed.

[0003] In optoelectronic devices, the PEDOT:PSS material belongs to a very efficient hole injection material. However, since PEDOT:PSS itself is acidic, it will corrode indium tin oxide (ITO) in optoelectronic devices. After the decomposition of ITO, the released indium ions enter the device, which will cause attenuation of the device performance and lifespan. Summary of the Invention

[0004] Embodiments of the present disclosure provide an optoelectronic device, including:

[0005] A substrate;

[0006] A first electrode layer located on one side of the substrate, and the material of the first electrode layer includes indium-containing oxide;

[0007] A modification layer located on the surface of the first electrode layer away from the substrate, and the modification layer includes: an indium ion capture group, a siloxane group, and a linking group connecting the indium ion capture group and the siloxane group, and the siloxane group is fixed on the surface of the first electrode layer.

[0008] In a possible implementation manner, in the above optoelectronic device provided by the embodiments of the present disclosure, the indium ion capture group includes three pyridine groups.

[0009] In a possible implementation manner, in the above optoelectronic device provided by the embodiments of the present disclosure, the siloxane group is formed by the reaction of a silyl group connected to the linking group and a hydroxyl group existing on the surface of the indium-containing oxide, and the molecular formula of the silyl group is Si-R2R3R4, where the R2 group, the R3 group, and the R4 group include one of methoxy, ethoxy, tert-butyl, and chloride ion.

[0010] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the R2 group, the R3 group, and the R4 group are the same group.

[0011] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the R2 group, the R3 group, and the R4 group are all methoxy groups.

[0012] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the linking group includes one of an alkyl group and an aromatic group.

[0013] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the aromatic group includes at least one of a phenyl group, a naphthyl group, and a thiophene group.

[0014] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the number of C atoms contained in the carbon chain of the linking group is 6 to 10.

[0015] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the thickness of the modification layer is 1 nm to 2 nm.

[0016] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the material of the first electrode layer includes one of ITO and IZO.

[0017] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, it further includes: a hole injection layer located on the side of the first electrode layer away from the substrate, and the material of the hole injection layer is acidic.

[0018] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the material of the hole injection layer includes PEDOT:PSS.

[0019] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the optoelectronic device is a light-emitting device, and the optoelectronic device further includes a light-emitting layer located on the side of the hole injection layer away from the modification layer.

[0020] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the material of the light-emitting layer is a quantum dot or an organic substance.

[0021] In a possible implementation, in the above optoelectronic device provided by the embodiments of the present disclosure, the optoelectronic device is a photovoltaic device, and the optoelectronic device further includes an active layer located on the side of the hole injection layer away from the modification layer. Description of the Drawings

[0022] Figure 1 FIG. 1 is a schematic structural diagram of an optoelectronic device provided by an embodiment of the present disclosure;

[0023] Figure 2 FIG. 2 is another schematic structural diagram of an optoelectronic device provided by an embodiment of the present disclosure;

[0024] Figure 3 FIG. 3 is a general structural formula of a modifying material in an optoelectronic device provided by an embodiment of the present disclosure;

[0025] Figure 4 FIG. 4 is a schematic diagram of the principle of indium ion capture by an indium ion capture group of a modifying material in an optoelectronic device provided by an embodiment of the present disclosure;

[0026] Figure 5 FIG. 5 is a specific molecular structure of a modifying material in an optoelectronic device provided by an embodiment of the present disclosure;

[0027] Figure 6 FIG. 6 is a schematic diagram of the principle of the action between a modifying layer and a first electrode layer in an optoelectronic device provided by an embodiment of the present disclosure;

[0028] Figure 7 FIG. 7 is a chemical reaction formula for preparing a modifying material in an optoelectronic device provided by an embodiment of the present disclosure;

[0029] Figure 8 FIG. 8 is a schematic flow chart of a manufacturing method of an optoelectronic device provided by an embodiment of the present disclosure. Detailed Embodiments

[0030] Currently, in QD devices, the most classical structure is: ITO / PEDOT:PSS / TFB / QD / ZnO / Al, and the EQE of the device can reach more than 20%. However, since PEDOT:PSS itself is acidic, it will corrode ITO in the device. After ITO decomposes, the released indium ions enter the light-emitting layer, which will cause attenuation of the device performance and lifespan.

[0031] To replace the combination of PEDOT:PSS / TFB, it has been proposed to use oxides as the hole injection layer, such as NiO, WOx, VOx, MoOx, etc. However, since the energy levels and mobilities of oxides are different from those of the PEDOT:PSS / TFB system, and oxides may also quench QD, the final EQE of devices using this solution is currently not high. The highest EQE is 8.1%, and the device structure is ITO / NiO / Al2O3 / QD / ZnO / Al. On the other hand, if PEDOT:PSS cannot be completely eliminated, another approach is to use oxides and PEDOT:PSS in combination, hoping to separate PEDOT and ITO with oxides to obtain better lifetime. However, due to the matching problem of the energy levels and mobilities of inorganic oxides, the EQE of devices using this solution is also not ideal currently. The highest EQE of the devices currently is 12.47% for ITO / WO3 NPs / PEDOT:PSS / TFB / QD / ZnO / Al, which is still about half of the EQE of devices using PEDOT:PSS.

[0032] The optoelectronic device provided by the embodiments of the present disclosure proposes a new idea. Without changing the original device structure, a modification layer is inserted between PEDOT:PSS and ITO to slow down the corrosion of ITO by PEDOT:PSS and capture indium ions to improve the device lifetime. Moreover, since the modification layer can form a monolayer during fabrication and its thickness is extremely thin, it will not affect the carrier transport properties of the device itself. Therefore, it will not affect the device efficiency.

[0033] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the present disclosure will be further described in detail below with reference to the accompanying drawings. Apparently, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of them. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present disclosure without creative efforts shall fall within the scope of protection of the present disclosure.

[0034] The shapes and sizes of the components in the drawings do not reflect the actual proportions, and the purpose is only to schematically illustrate the content of the present disclosure.

[0035] Specifically, an optoelectronic device provided by an embodiment of the present disclosure, as Figure 1 and Figure 2 shown, includes:

[0036] Substrate 1;

[0037] The first electrode layer 2 is located on one side of the substrate 1. The material of the first electrode layer 2 includes indium-containing oxide; the modification layer 21 is located on the surface of the first electrode layer 2 on the side facing away from the substrate 1. The modification layer 21 includes: an indium ion capture group X, a siloxane group, and a linking group R1 connecting the indium ion capture group X and the siloxane group. The siloxane group is fixed on the surface of the first electrode layer 2.

[0038] Specifically, in the above optoelectronic device provided by the embodiments of the present disclosure, a modification layer 21 is added to the surface of the first electrode layer 2 on the side away from the substrate 1. The presence of the modification layer 21 can prevent the first electrode layer 2 from directly contacting other film layers, and can play a role in slowing down the corrosion problem of the indium-containing oxide constituting the first electrode layer 2. Moreover, the indium ion capture group X contained in the modification layer 21 can fix the indium ions released after the corrosion of the indium-containing oxide on the surface of the first electrode layer 2, preventing the indium ions from moving into the interior of the optoelectronic device, thereby increasing the lifespan of the optoelectronic device.

[0039] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, the material of the first electrode layer 2 may include one of ITO and IZO.

[0040] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, as Figure 1 and Figure 2 shown, it may further include: a hole injection layer 3, which is located on the side of the first electrode layer 2 facing away from the substrate 1, and the material of the hole injection layer 3 is acidic.

[0041] Specifically, the material of the hole injection layer 3 may include PEDOT:PSS. PEDOT:PSS is a mixture of two materials. PEDOT is a polymer of EDOT (3,4-ethylenedioxythiophene monomer), and PSS is polystyrene sulfonate, where PSS has a certain acidity.

[0042] Specifically, the acidic hole injection layer 3 in the device will corrode the first electrode layer 2. The indium ions released after the decomposition of the first electrode layer 2 enter the light-emitting layer, which will cause attenuation of the device performance and lifespan. Therefore, a modification layer 21 is inserted between the hole injection layer 3 and the first electrode layer 2. The presence of the modification layer 21 can prevent the first electrode layer 2 from directly contacting the hole injection layer 3, and can play a role in slowing down the corrosion problem of the indium-containing oxide constituting the first electrode layer 2.

[0043] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, the optoelectronic device may be a light-emitting device. At this time, as Figure 1 shown, the optoelectronic device may further include a light-emitting layer 4 located on the side of the hole injection layer 3 facing away from the modification layer 21. In addition, as Figure 1As shown, the optoelectronic device may further include a second electrode layer 5, an electron transport layer 6 located between the second electrode layer 5 and the light-emitting layer 4, and a hole transport layer 7 located between the light-emitting layer 4 and the hole injection layer 3.

[0044] Optionally, in the optoelectronic device provided in the embodiments of the present disclosure, the material of the light-emitting layer 4 may be quantum dots QD or organic EL. When the light-emitting layer 4 is made of a quantum dot material, the material of the electron transport layer 6 may be ZnO, and the material of the hole transport layer 7 may be TFB. The second electrode layer 5 is generally a cathode layer, and its material may be Al.

[0045] Specifically, when the optoelectronic device is a light-emitting device, the light-emitting device can be applied to a display device, and the display device can be: a mobile phone, a tablet computer, a television, a monitor, a laptop computer, a digital photo frame, a navigator, or any product or component with a display function.

[0046] Optionally, in the optoelectronic device provided in the embodiments of the present disclosure, the optoelectronic device may also be a photovoltaic device. At this time, as Figure 2 shown, the optoelectronic device may further include an active layer 8 located on the side of the hole injection layer 3 away from the modification layer 21. The material of the active layer 8 may be PBDT-DTNT:PC71BM. In addition, as Figure 2 shown, the optoelectronic device may further include a second electrode layer 5 on the side of the active layer 8 away from the hole injection layer 3. The material of the second electrode layer 5 may be Al.

[0047] Specifically, when the optoelectronic device is a photovoltaic device, the photovoltaic device can be applied to a solar cell.

[0048] In addition, the optoelectronic device provided in the embodiments of the present disclosure may also be other devices including the direct contact structure of ITO and PEDOT:PSS, and the device lifetime can be increased by adding a modification layer between ITO and PEDOT:PSS.

[0049] Specifically, in the optoelectronic device provided in the embodiments of the present disclosure, the modification layer 21 is formed by the reaction of the modification material with the hydroxyl groups on the surface of the first electrode layer 2. Specifically, the siloxane groups in the modification layer 21 are formed by the reaction of the silyl group Si-R2R3R4 connected to the linking group R1 and the hydroxyl groups existing on the surface of the indium-containing oxide. As Figure 3 shown, the modification material specifically includes an indium ion capture group X, a silyl group Si-R2R3R4, and a linking group R1 connected between the indium ion capture group X and the silyl group Si-R2R3R4. Its material general formula is X-R1-Si-R2R3R4, where X is an indium ion capture group, R1 is a linking group, and Si-R2R3R4 is a silyl group.

[0050] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, the indium ion capture group X may include three pyridine groups. As Figure 3 shown, the N atoms on the three pyridine rings can bind to indium ions. As Figure 4 shown, the diffused indium ions are fixed on the surface of the first electrode layer 2 to prevent indium ions from entering the device interior and affecting the device efficiency and lifespan.

[0051] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, the molecular formula of the silyl group is SiR2R3R4, where the R2 group, R3 group, and R4 group include one of methoxy, ethoxy, tert-butyl, and chloride ion.

[0052] Specifically, the function of the silyl group Si-R2R3R4 is to react with the hydroxyl groups on the surface of the first electrode layer 2 after hydrolysis to fix the modification layer 21 on the surface of the first electrode layer 2.

[0053] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, the R2 group, R3 group, and R4 group in the silyl group can be the same group or different groups. When they are different groups, there will be certain differences in the hydrolysis rate and solubility of different groups. There is no requirement for the arrangement of the R2 group, R3 group, and R4 group in the silyl group.

[0054] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, the R2 group, R3 group, and R4 group can all be methoxy (OMe, Me is methyl), and its specific molecular structural formula is as Figure 5 shown.

[0055] Specifically, taking R2 = R3 = R4 = OMe as an example, the hydrolysis mechanism of the modification material is hydrolysis to silanol after heating, that is, X-R1-Si(OMe)3 → X-R1-Si(OH)3. The silanol Si(OH)3 can react with the hydroxyl groups on the surface of the first electrode layer 2 to become siloxane, thereby tightly connecting with the first electrode layer 2. As Figure 6 shown.

[0056] Optionally, in the above optoelectronic device provided by the embodiments of the present disclosure, the linking group R1 can be an alkyl group, an aromatic group, etc. Figure 5 In

[0057] it, the linking group R1 being an alkyl group is taken as an example for illustration.

[0058] Specifically, the linking group R1 has two functions. One is to serve as a linker to connect the indium ion capturing group X and the silyl group Si-R2R3R4 together. The other is to act as a spacer to increase the distance between the first electrode layer 2 and the hole injection layer 3, thereby slowing down the corrosion of ITO by PEDOT:PSS.

[0059] Specifically, the longer the length of the linking group R1, the thicker the thickness of the modification layer 21 formed by the modification material. As a result, the hole injection layer 3 is farther away from the first electrode layer 2, and the corrosion effect will be weaker. However, if the thickness of the modification layer 21 is too thick, it will affect the carrier transport.

[0060] Preferably, in the optoelectronic device provided in the embodiment of the present disclosure, the number of C atoms contained in the carbon chain of the linking group R1 is preferably 6 to 10. Currently, the quantum dot ligands mainly applied to QLED devices are octanethiol and dodecanethiol. When the number of C atoms is 6 to 10, the overall thickness of the modification layer 21 is about 1 nm, which can minimize the corrosion effect of the hole injection layer on the first electrode layer while not affecting the carrier transport.

[0061] Optionally, in the optoelectronic device provided in the embodiment of the present disclosure, since the modification layer 21 is formed on the surface of the first electrode layer 2 by the reaction of the hydrolysis of the modification material with the hydroxyl groups on the surface of the first electrode layer 2, it is ensured that the modification layer 21 is composed of a single layer of molecules. The thickness of the modification layer 21 is the molecular length of a modification material. Depending on the molecular length, the film thickness of the modification layer 21 is different, and the thickness of the modification layer 21 is generally 1 nm - 2 nm.

[0062] Specifically, in the optoelectronic device provided in the embodiment of the present disclosure, the modification material can be prepared as follows: Dissolve 2 g of trimethoxy(7-octen-1-yl)silane and 1.5 g of 4'-bromo-2,2':6',2”-terpyridine in 50 mL of dry toluene, add a catalytic amount of tetrakis(triphenylphosphine)palladium, and protect with nitrogen, then reflux for 10 hours. After the reaction is completed, spin-dry the product and purify it by column chromatography (hexane:ethyl acetate = 3:1) to finally obtain this molecule. The specific reaction formula is as Figure 7 shown.

[0063] Based on the same inventive concept, the embodiment of the present disclosure also provides a manufacturing method of the above optoelectronic device. Since the principle of solving problems by this manufacturing method is similar to that of the aforementioned optoelectronic device, the implementation of this manufacturing method can refer to the implementation of the optoelectronic device, and the repeated parts will not be elaborated.

[0064] Specifically, a manufacturing method of an optoelectronic device provided in the embodiment of the present disclosure, as Figure 8 shown, includes:

[0065] S1. Provide a substrate;

[0066] S2. Form a first electrode layer on the substrate using indium-containing oxide.

[0067] S3. Coat a modifying material on the first electrode layer, where the modifying material includes an indium ion capturing group, a silyl group, and a linking group connecting the indium ion capturing group and the silyl group.

[0068] S4. Heat the substrate coated with the modifying material to hydrolyze the silyl group to generate a silanol group, and the silanol group reacts with the hydroxyl group existing on the surface of the indium-containing oxide to generate a siloxane group.

[0069] S5. After removing the remaining modifying material from the reaction, form a modifying layer on the surface of the first electrode layer.

[0070] Optionally, in the above manufacturing method provided by the embodiments of the present disclosure, as Figure 8 shown, it may further include:

[0071] S6. Form a hole injection layer on the modifying layer using PEDOT:PSS.

[0072] Specifically, after the hole injection layer is fabricated, other film layers can be fabricated as needed. For example, taking the quantum dot light-emitting device structure as Figure 1 shown, the above manufacturing method provided by the embodiments of the present disclosure will be described in detail. Specifically, the manufacturing process is as follows:

[0073] 1) Ultrasonically clean the ITO substrate in deionized water, ethanol, and acetone for 10 minutes in sequence.

[0074] 2) Clean the ITO substrate in an oxygen plasma cleaner for 10 minutes before use.

[0075] 3) Spin-coat the solution of the modifying material on the ITO substrate at a speed of 4000 r / min.

[0076] 4) Place the ITO substrate on a hot stage and heat it at 80 °C for 10 minutes to make the silyl group of the modifying material react with the hydroxyl group on the ITO surface.

[0077] 5) Rinse the ITO substrate with n-hexane to wash away the solution of the unreacted modifying material.

[0078] 6) Place the ITO substrate on a hot stage and heat it at 80 °C for 10 minutes to remove the solvent in the solution of the modifying material and form a modifying layer.

[0079] 7) Spin-coat the PEDOT:PSS solution on the ITO substrate with the modifying layer in the air at a speed of 4000 r / min, and then dry and anneal it at a high temperature of 150 °C for 20 minutes to obtain a hole injection layer.

[0080] 8) Transfer the ITO substrate to a nitrogen-filled glove box, then spin-coat the TFB solution at a speed of 2000 r / min and dry-anneal it at 120 °C for 20 min to obtain the hole transport layer.

[0081] 9) Spin-coat the quantum dot solution at a speed of 2000 r / min and dry-anneal it at 120 °C for 20 min to obtain the light-emitting layer.

[0082] 10) Spin-coat the zinc oxide solution at a speed of 2000 r / min and dry-anneal it at 120 °C for 20 min to obtain the electron transport layer.

[0083] 11) Under a high vacuum of 5×10 -4 Pa, deposit an aluminum electrode in an evaporation device using a metal mask to obtain the second electrode layer.

[0084] For the optoelectronic device provided by the embodiment of the present disclosure, a modification layer is added to the surface of the optoelectronic device on the side of the first electrode layer away from the substrate. The presence of the modification layer can prevent the first electrode layer from directly contacting other film layers, and can play a role in slowing down the corrosion problem of the indium-containing oxide constituting the first electrode layer. Moreover, the indium ion capture group contained in the modification layer can fix the indium ions released after the corrosion of the indium-containing oxide on the surface of the first electrode layer, preventing the indium ions from moving into the optoelectronic device, thereby increasing the lifespan of the optoelectronic device.

[0085] Obviously, those skilled in the art can make various changes and modifications to the present disclosure without departing from the spirit and scope of the present disclosure. Thus, if these modifications and variations of the present disclosure fall within the scope of the claims of the present disclosure and their equivalent technologies, the present disclosure also intends to include these changes and modifications.

Claims

1. An optoelectronic device, wherein, Comprising: A substrate substrate; A first electrode layer located on one side of the substrate substrate, the material of the first electrode layer comprising an indium-containing oxide; A modification layer located on the surface of the first electrode layer away from the substrate substrate, the modification layer comprising: an indium ion capture group, a siloxane group, and a linking group connecting the indium ion capture group and the siloxane group, the siloxane group being fixed on the surface of the first electrode layer; The indium ion capture group comprises three pyridine groups.

2. The optoelectronic device according to claim 1, wherein, The siloxane group is formed by reacting a silyl group connected to the linking group with a hydroxyl group present on the surface of the indium-containing oxide, and the molecular formula of the silyl group is Si-R2R3R4, wherein the R2 group, the R3 group, and the R4 group comprise one of a methoxy group, an ethoxy group, a tert-butyl group, and a chloride ion.

3. The optoelectronic device according to claim 2, wherein, The R2 group, the R3 group, and the R4 group are the same group.

4. The optoelectronic device according to claim 3, wherein, The R2 group, the R3 group, and the R4 group are all methoxy groups.

5. The optoelectronic device according to claim 1, wherein, The linking group comprises one of an alkyl group and an aromatic group.

6. The optoelectronic device according to claim 5, wherein, The aromatic group comprises at least one of a phenyl group, a naphthyl group, and a thiophene group.

7. The optoelectronic device according to claim 5, wherein, The number of C atoms contained in the carbon chain of the linking group is 6 to 10.

8. The optoelectronic device according to claim 1, wherein, The thickness of the modification layer is 1 nm to 2 nm.

9. The optoelectronic device according to claim 1, wherein, The material of the first electrode layer comprises one of ITO and IZO.

10. The optoelectronic device according to any one of claims 1-9, wherein, Further comprising: A hole injection layer located on the side of the first electrode layer facing away from the substrate substrate, the material of the hole injection layer being acidic.

11. The optoelectronic device according to claim 10, wherein, The material of the hole injection layer comprises PEDOT:PSS.

12. The optoelectronic device according to claim 10, wherein, The optoelectronic device is a light-emitting device, and the optoelectronic device further comprises a light-emitting layer located on the side of the hole injection layer facing away from the modification layer.

13. The optoelectronic device according to claim 12, wherein, The material of the light-emitting layer is a quantum dot or an organic substance.

14. The optoelectronic device according to claim 10, wherein, The optoelectronic device is a photovoltaic device, and the optoelectronic device further comprises an active layer located on the side of the hole injection layer facing away from the modification layer.

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