A high-transmission-reflection tunable optoelectronic material, optoelectronic device and its fabrication method

Abstract

This invention discloses a high-performance optoelectronic material and device fabrication method based on the low hysteresis effect of ferrous metatungstate. The ferrous metatungstate aqueous solution is obtained by reacting a metatungstic acid solution with a ferrous hydroxide solution and ethylene glycol in a reaction vessel, followed by centrifugation and collection of the supernatant. The ferrous metatungstate aqueous solution is sealed between two substrates. The transmission and reflectivity of the optoelectronic device are determined by the transmission and reflectivity of the substrates, and the tunability of the reflection is determined by the reflectivity of the reflective substrate. This invention effectively solves the problem in existing technologies where the introduction of oxidants or reducing agents into liquid optoelectronic materials alters the solution environment and affects device performance, while significantly ensuring the device's transmission and reflectivity.

Description

Technical Field

[0001] This invention relates to the field of optoelectronics, specifically to a high-transmission-reflection tunable optoelectronic material, optoelectronic device, and its preparation method. Background Technology

[0002] Liquid optoelectronic materials refer to optoelectronic materials that participate in the reaction in a liquid ionic state during the photoelectric transformation process. These materials change color when charged and slowly fade when the power is off. Introducing oxidants or reductants can effectively accelerate the reaction process; however, the introduction of oxidants and reductants will cause changes in the liquid environment of the optoelectronic material, such as pH, ionic conductivity, and solution viscosity, thus affecting the performance of optoelectronic devices. Therefore, it is essential to invent a liquid optoelectronic material with inherent oxidizing or reducing properties. Summary of the Invention

[0003] The purpose of this invention is to overcome the above-mentioned defects in the prior art and provide a high-transmission and high-reflection tunable optoelectronic device made of ferrous metatungstate.

[0004] The above objectives can be achieved through the following technical solutions:

[0005] This invention provides a method for preparing a high-transmission-reflection tunable optoelectronic material, comprising the following steps: mixing and reacting a metatungstic acid solution, a ferrous hydroxide solution, and ethylene glycol, followed by centrifugation, and collecting the supernatant to obtain a ferrous metatungstic acid solution, which is the high-transmission-reflection tunable optoelectronic material. Preferably, the solvent of the metatungstic acid solution is water, with a concentration of 0.01 mol / L to 0.2 mol / L. Metatungstic acid is the reactant, reacting with ferrous hydroxide.

[0006] Preferably, the solvent for the ferrous hydroxide solution is water with a concentration of 0.1 mol / L to 2 mol / L, and ferrous hydroxide is the reactant that reacts with metatungstic acid.

[0007] Preferably, the mass concentration ratio of metatungstic acid to ferrous hydroxide is 1:10 to 1:1. Since the two are acid-base reactions, the reaction time is relatively long and it is difficult to react completely, so one can be in appropriate excess.

[0008] Preferably, the mass concentration ratio of ethylene glycol to ferrous hydroxide is 1:1 to 1:3. Ferrous hydroxide is more easily oxidized to ferric hydroxide by air, and ethylene glycol is added as a reducing agent to prevent air oxidation.

[0009] Preferably, the mixing method of metatungstic acid solution, ferrous hydroxide solution, and ethylene glycol is as follows: first, ethylene glycol is added to the ferrous hydroxide solution to obtain solution A, and then solution A is added dropwise to the metatungstic acid solution; or the metatungstic acid solution is added dropwise to solution A. Slow addition prevents side reactions between metatungstic acid and ethylene glycol.

[0010] Preferably, the reaction conditions are: reacting in a reactor at 80–150°C for 2–10 hours. Ferrous hydroxide ions are easily oxidized; placing them in the reactor allows ethylene glycol to fully reduce any ferric ions present.

[0011] Preferred,

[0012] The centrifugation speed is 1000-5000 r / s, and the centrifugation time is 5-30 min.

[0013] An appropriate rotation speed can effectively remove the precipitate produced by excessive reaction.

[0014] The present invention also provides a high-transmission, high-reflection tunable optoelectronic material prepared by the above-described preparation method.

[0015] This invention also provides a high-transmission-reflection tunable optoelectronic device, characterized in that it comprises two substrates and a sandwich layer placed between the two substrates, wherein the aforementioned optoelectronic material is sealed within the sandwich layer, and the thickness of the sandwich layer is 1 μm to 100 μm. The transmittance of the sandwich layer varies with different thicknesses; the thicker the sandwich layer, the lower the transmittance, but it can maintain a transmittance of over 90%.

[0016] Preferably, the transmission and reflection properties of the optoelectronic device are determined by the transmission and reflection properties of the substrate. If both substrates are transmissive, it is a projection device; if one substrate reflects and the other transmits, it is a reflection device. The reflective substrate is a substrate coated with a reflective material; the transmissive substrate is a transparent conductive material. Devices with different properties have different application scenarios.

[0017] Preferably, the reflective material is one or more of aluminum and silver; the transmissive substrate is one or more of ITO and FTO. This invention has the following advantages and effects compared to the prior art:

[0018] 1) The tunable high-transmission and high-reflection ferrous metatungstate device disclosed in this invention is relatively simple, has fewer side reactions, and can easily obtain ferrous metatungstate.

[0019] 2) The ferrous metatungstate prepared by this invention can simultaneously possess the photoelectric properties of liquid optoelectronic materials and the oxidizing properties required during the reaction, effectively solving the problem in the prior art where the introduction of oxidants or reducing agents into liquid optoelectronic materials leads to changes in the solution environment and thus affects the use of the device.

[0020] 3) Based on the low hysteresis effect of ferrous metatungstate, the transmission and reflection devices made from the ferrous metatungstate aqueous solution prepared in this invention have high transmittance or reflectance. The ferrous metatungstate aqueous solution is sealed in the middle of the sandwich between two substrates, and the device can change color after being energized, thereby adjusting the transmittance and reflectance. Attached Figure Description

[0021] Figure 1This is the schematic diagram of the device; where 1 is the reflective substrate, 2 is the transmissive substrate, and 3 is the ferrous metatungstate solution.

[0022] Figure 2 This is a test diagram for Example 1.

[0023] Figure 3 This is a test diagram for Example 2.

[0024] Figure 4 This is the test image for Comparative Example 3. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention are described clearly and completely. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] Example 1:

[0027] Prepare 10 mL of 0.05 mol / L metatungstic acid (H6H2W). 12 O 40 A green mixed solution was obtained by mixing 10 mL of 0.5 mol / L ferrous hydroxide aqueous solution with 10 mL of ethylene glycol and stirring. This green mixed solution was then added dropwise to a metatungstic acid solution, yielding 30 mL of a reddish-brown mixed solution. The solution was transferred to a 50 mL reaction vessel and heated at 100 °C for 6 h, resulting in a reddish-turbid solution. This solution was centrifuged at 3000 r / s for 10 min to obtain a light red solution. This light red solution was sealed in a sandwich layer placed between two ITO conductive glass substrates to fabricate a transmissive optoelectronic device. The sandwich layer thickness was 20 μm. The transmittance of the device was measured, showing good transmittance of 78%. After applying 1.5 V for 100 s and then disconnecting the power, the transmittance spectrum at 700 nm was obtained as shown below. Figure 2 As shown, the device exhibits a good photoelectric response time, within 10 seconds. However, a high concentration of ferrous ions can cause irregular changes in the device's color during the fading process.

[0028] Example 2

[0029] Prepare 10 mL of 0.1 mol / L metatungstic acid aqueous solution and 10 mL of 0.1 mol / L ferrous hydroxide aqueous solution. Add 10 mL of ethylene glycol to the ferrous hydroxide aqueous solution and stir to obtain a green mixed solution. Add the green mixed solution dropwise to the metatungstic acid solution to obtain 30 mL of reddish-brown mixed solution. Transfer the solution to a 50 mL reaction vessel and heat at 80 °C for 6 h to obtain a clear red solution. Centrifuge at 3000 r / s for 10 min to obtain a light red solution. Seal the light red solution in a sandwich between a transparent ITO conductive glass substrate and a reflective aluminum mirror substrate to fabricate a reflective optoelectronic device. The initial reflectivity of the reflective substrate is 80%, and the sandwich thickness is 20 μm. The transmittance of the device was measured, and the device has a good transmittance of 76%. After applying a 1.5 V current for 100 s and then disconnecting the power, the transmittance spectrum at 700 nm is shown below. Figure 2 As shown, the device exhibits a good photoelectric response time, which is within 10 seconds.

[0030] Comparative Example 3

[0031] 10 mL of 0.1 mol / L ammonium metatungstate solution was prepared, and 10 mL of 0.1 mol / L ferrous chloride solution was added to obtain 20 mL of a clear, reddish-brown solution. This reddish-brown solution was sealed in a sandwich layer placed between two transparent substrates to fabricate a transmissive optoelectronic device. The sandwich layer thickness was 20 μm. The transmittance of the device was measured, and it reached 72%. After applying a 1.5V voltage for 100 s and then disconnecting the voltage, the transmittance spectrum at 700 nm was measured as follows. Figure 3 As shown, the device has the disadvantages of generally slow photoelectric response time and inability to completely fade.

Claims

1. A method for preparing a high-transmission, high-reflection tunable optoelectronic material, characterized in that, The method comprises the following steps: mixing a metatungstate solution, a ferrous hydroxide solution and ethylene glycol, centrifuging the mixture, and obtaining a metatungstate ferrous solution from the supernatant, i.e. the high-transmission reflective tunable photoelectric material. The mixing method of the metatungstate solution, the ferrous hydroxide solution and the ethylene glycol is: first, adding the ethylene glycol into the ferrous hydroxide solution to obtain solution A, and then adding the solution A drop by drop into the metatungstate solution, or adding the metatungstate solution drop by drop into the solution A.

2. The production method according to claim 1, characterized by, The solvent of the metatungstate solution is water, and the concentration is 0.01mol / L-0.2mol / L. The solvent of the ferrous hydroxide solution is water, and the concentration is 0.1mol / L-2mol / L.

3. The preparation method according to claim 1, characterized in that, The molar concentration ratio of the metatungstate to the ferrous hydroxide is 1:10-1:

1. The volume ratio of the ethylene glycol to the ferrous hydroxide solution is 1:1-1:

3.

4. The method of claim 1, wherein, The reaction condition is that the reaction is carried out at 80-150℃ in a reaction kettle for 2-10h.

5. The preparation method according to claim 1, characterized in that, The centrifugal speed is 1000-5000r / s, and the centrifugal time is 5-30min.

6. A high-transmission reflective tunable photoelectric material prepared by the method of any one of claims 1-5.

7. A high transmission reflective electro-optical device, characterized in that The photoelectric material is sealed in the interlayer, and the thickness of the interlayer is 1μm-100μm.

8. The optoelectronic device of claim 7, wherein, When both of the two substrates are transmission substrates, the device is a transmission device; when one of the two substrates is a reflective substrate and the other is a transmission substrate, the device is a reflective device; the reflective substrate is a reflective material coated substrate; and the transmission substrate is a transparent conductive material.

9. The optoelectronic device of claim 8, wherein, The reflective material is one or more of aluminum and silver; and the transmission substrate is one or more of ITO and FTO.

Images