A method for preparing a flexible optical storage device using two-dimensional materials

Abstract

The present invention belongs to the technical field of flexible electronic preparation, and is specifically a method for preparing a flexible optical storage device using two-dimensional materials. The method of the present invention comprises: using a flexible material as a substrate; depositing a layer of oxide material on the substrate; transferring a two-dimensional semiconductor material to the substrate; forming metal electrodes at both ends of the two-dimensional material; spin coating a layer of organic matter on the entire device; transferring a layer of two-dimensional BN material on the organic matter; and finally depositing a layer of ITO electrode material on the BN material. Compared with the prior art, the present invention can realize an erasable optical storage function. At the same time, the device can be bent and folded at will, and the electrical performance of the device remains unchanged after bending, meeting the application requirements of certain optical communications and optical storage.

Description

Technical Field

[0001] The invention belongs to the technical field of flexible electronic preparation, and in particular relates to a method for preparing a flexible optical storage device. Background Art

[0002] With the rapid growth of digital resource information and data volume, the requirements for storage density, access method and storage rate of storage are constantly increasing. Among them, optical storage technology is a technology that converts optical information into readable digital technology. At present, traditional optical storage technology uses laser to form depressions on the substrate by laser ablation on polycarbonate plastic to record information. The disadvantage of this information recording method by laser ablation is that it requires high power density of the laser light source (>10 6 W / cm 2 ), the equipment is complex and cannot be lightweight. In addition, the damage to the substrate material caused by repeated ablation leads to a limited number of data erasures. At the same time, dust and scratches on the plastic substrate have a certain impact on data reading.

[0003] In order to meet the requirements of lightweight and easy to carry, the present invention uses a flexible substrate as the base material and utilizes the photoelectric effect of two-dimensional semiconductor materials. As long as the energy of the incident light is greater than the direct bandgap width of the two-dimensional material, photogenerated carriers can be generated. Therefore, the optical information is converted into processable electronic information. This method does not require high power density of the incident light. As long as it is greater than 10 3 W / cm 2 That is, the requirements for incident light equipment and substrate materials are greatly reduced, and the data retention time and erase and write times are improved.

[0004] The present invention is studied based on the above background. Summary of the invention

[0005] The purpose of the present invention is to provide a method for preparing a flexible optical storage device using two-dimensional materials in order to overcome the defects of the above-mentioned prior art.

[0006] The method for preparing a flexible optical storage device using a two-dimensional material provided by the present invention comprises the following specific steps:

[0007] (1) Using flexible materials as substrates;

[0008] (2) depositing a layer of oxide material on the substrate;

[0009] (3) Transferring the two-dimensional semiconductor material to a substrate;

[0010] (4) forming metal electrodes at both ends of the two-dimensional semiconductor material;

[0011] (5) Spin coating a layer of organic matter on the material obtained in step (4);

[0012] (6) Transferring a layer of BN material onto the organic matter;

[0013] (7) Finally, a layer of ITO electrode material is deposited on the BN material.

[0014] Further:

[0015] In step (1), the flexible material is selected from one of polyimide, polyethylene terephthalate or polyethylene naphthalate, and has a thickness of 10-300 µm.

[0016] In step (2), the oxide material is selected from one of SiO2 and Al2O3, and its thickness is 20-300nm.

[0017] In step (3), the two-dimensional semiconductor material is one of MoS2, MoSe2, WS2, WSe2, black phosphorus and the like, and the thickness of the two-dimensional semiconductor material is a single atomic layer.

[0018] In step (4), the metal electrode material is a Ti / Au or Cr / Au metal layer with a thickness of 10-200 nm.

[0019] In step (5), the organic matter is a 1,4-bis(4-methylstyrene)benzene compound with a thickness of 1-10 nm.

[0020] In step (6), the thickness of the two-dimensional BN material is 10-100 nm.

[0021] In step (7), the thickness of the ITO electrode material is 50-100 nm.

[0022] The flexible optical storage device prepared by the present invention has the following working principle: when incident light irradiates the two-dimensional semiconductor material, photogenerated carriers are generated because the energy of the incident light is greater than the direct bandgap width of the two-dimensional semiconductor material, and a positive electric field is applied to the ITO upper electrode at the same time. Under the action of the electric field, the photogenerated electrons in the two-dimensional semiconductor material enter the organic material through tunneling and are bound, thereby completing information storage. If information erasure is required, a reverse electric field can be applied to release the bound electrons in the organic material into the two-dimensional material, and finally complete the writing and erasing process of optical information.

[0023] Compared with the currently common optical storage technology, the present invention has the following beneficial effects:

[0024] (1) The two-dimensional substrate used in the present invention is very flexible, so the present invention can be bent and folded at will. After bending, the electrical properties of the device remain unchanged, which meets the application requirements of certain optical communications and optical storage, and can also meet the technical requirements of miniaturization of portable electronic products.

[0025] (2) The laser used in the present invention is a low-power laser, which does not damage the substrate material and is within the tolerable range of the human body.

[0026] (3) The present invention adopts the photoelectric conversion method to realize information storage and erasure, which has the advantages of a large number of erasable times and a long storage time. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the structure of the flexible optical storage device prepared by the present invention.

[0028] Markings in the figure: 1 is the substrate, 2 is the oxide material, 3 is the two-dimensional semiconductor material, 4 is the metal electrode, 5 is the organic material, 6 is the BN material, and 7 is the ITO electrode. DETAILED DESCRIPTION

[0029] The embodiments herein and various features and related details will be explained more completely with reference to the non-limiting embodiments illustrated in the accompanying drawings and described in detail in the following description, in conjunction with the implementation methods described below in conjunction with specific examples. Descriptions of well-known components and processing techniques are omitted so as not to unnecessarily obscure the embodiments herein. Conventional processes well-known in semiconductor processes may be used when making the structures. The examples used herein are merely to help understand the manner in which the embodiments herein may be implemented, and to further enable those skilled in the art to implement the embodiments herein. Thus, the examples herein should not be construed as limiting the scope of the embodiments herein.

[0030] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the drawings only show the components related to the present invention rather than being drawn according to the number, shape and size of the components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout type may also be more complicated.

[0031] The structure of the two-dimensional flexible light-emitting array prepared by the present invention is as follows Figure 1 As shown, it includes a substrate 1, an oxide material 2 deposited on the substrate 1, a two-dimensional semiconductor material 3 transferred to the oxide material 2, an electrode material 4 deposited at both ends of the two-dimensional semiconductor material 3, an organic material 5 spin-coated on the device, a BN material 6 transferred to the organic material 5, and an ITO electrode material 7 deposited on the BN material 6.

[0032] The flexible optical storage device with the above structure can be prepared by the method in the following embodiments.

[0033] Example 1

[0034] A method for preparing a flexible optical storage device comprises the following steps:

[0035] (1) 100µm polyethylene terephthalate (PET) film was used as the flexible material substrate.

[0036] (2) A 50 nm thick SiO2 material layer was deposited on the PET substrate by sputtering. The sputtering target material used was a SiO2 target with a purity of 99.99%. The sputtering gas was argon with a gas flow rate of 10 ml / min, a working gas pressure of 1 Pa, and a sputtering time of 30 min.

[0037] (3) Transfer the single-layer MoS2 material to the SiO2 material using mechanical exfoliation transfer.

[0038] (4) Spin-coat a 1µm thick photoresist on the surface of the MoS2 material, and prepare two electrode patterns on the surface of the MoS2 material by UV exposure and development. Deposit a 20nm thick metal Ti layer and an 80nm thick Au electrode layer on the surface of the MoS2 by sputtering. The sputtering targets are 99.99% pure Ti target and Au target, the sputtering gas is argon, the gas flow rate is 50 ml / min, the working pressure is 20 Pa, and the sputtering time is 60 min. Then remove the excess photoresist with acetone.

[0039] (5) Spray 2 nm thick 1,4-bis(4-methylstyrene)benzene organic matter on the surface of MoS2 material by thermal evaporation at a thermal evaporation temperature of 120 degrees for 10 minutes.

[0040] (6) Use mechanical exfoliation transfer to transfer 5 nm thick BN material onto organic material.

[0041] (7) Finally, a 100 nm thick layer of ITO transparent conductive material was deposited on the BN by sputtering. The sputtering target used was an ITO target with a purity of 99.99%. The sputtering gas was argon with a gas flow rate of 30 ml / min, a working gas pressure of 50 Pa, and a sputtering time of 15 min.

[0042] Example 2

[0043] (1) A 150µm polyimide (PI) film was used as the flexible material substrate.

[0044] (2) A 100 nm thick Al2O3 material layer was deposited on the PI substrate by sputtering. The sputtering target material used was an Al2O3 target with a purity of 99.99%. The sputtering gas was argon with a gas flow rate of 20 ml / min, a working gas pressure of 5 Pa, and a sputtering time of 20 min.

[0045] (3) Transfer the single-layer WS2 material to the Al2O3 material using mechanical exfoliation transfer.

[0046] (4) Spin-coat a 1µm thick photoresist on the surface of the WS2 material, and prepare two electrode patterns on the surface of the WS2 material by UV exposure and development. Deposit a 30nm thick Cr metal layer and a 100nm thick Au metal electrode layer on the surface of the WS2 by sputtering. The sputtering targets are Cr and Au targets with a purity of 99.99%. The sputtering gas is argon, the gas flow rate is 80 ml / min, the working pressure is 30 Pa, and the sputtering time is 20 min. Then remove the excess photoresist with acetone.

[0047] (5) Spray 3 nm thick 1,4-bis(4-methylstyrene)benzene organic matter on the surface of WS2 material by thermal evaporation. The thermal evaporation temperature is 120 degrees and the time is 15 minutes.

[0048] (6) Use mechanical exfoliation transfer to transfer 10 nm thick BN material onto organic material.

[0049] (7) Finally, a 120 nm thick layer of ITO transparent conductive material was deposited on the BN by sputtering. The sputtering target used was an ITO target with a purity of 99.99%. The sputtering gas was argon with a gas flow rate of 40 ml / min, a working gas pressure of 50 Pa, and a sputtering time of 15 min.

[0050] Example 3

[0051] (1) A 200 µm polyethylene naphthalate (PEN) flexible substrate film was used as the flexible material substrate.

[0052] (2) A 50 nm thick Al2O3 material layer was deposited on the PEN substrate by sputtering. The sputtering target material used was an Al2O3 target with a purity of 99.99%. The sputtering gas was argon with a gas flow rate of 20 ml / min, a working gas pressure of 2 Pa, and a sputtering time of 10 min.

[0053] (3) Transfer the single-layer WSe2 material to the Al2O3 material using mechanical exfoliation transfer.

[0054] (4) Spin-coat a 1µm thick photoresist on the surface of the WSe2 material, and prepare two electrode patterns on the surface of the WSe2 material by UV exposure and development. Deposit a 10nm thick Ti metal layer and a 150nm thick Au metal electrode layer on the surface of the WSe2 by sputtering. The sputtering targets are 99.99% pure Ti target and Au target, the sputtering gas is argon, the gas flow rate is 100ml / min, the working pressure is 30 Pa, and the sputtering time is 25 min. Then remove the excess photoresist with acetone.

[0055] (5) Spray 5 nm thick 1,4-bis(4-methylstyrene)benzene organic matter on the surface of WSe2 material by thermal evaporation. The thermal evaporation temperature is 120 degrees and the time is 20 minutes.

[0056] (6) Use mechanical exfoliation transfer to transfer 5 nm thick BN material onto organic material.

[0057] (7) Finally, a 200 nm thick layer of ITO transparent conductive material was deposited on the BN by sputtering. The sputtering target used was an ITO target with a purity of 99.99%. The sputtering gas was argon with a gas flow rate of 50 ml / min, a working gas pressure of 40 Pa, and a sputtering time of 20 min.

[0058] The above description of the embodiments is to facilitate the understanding and use of the present invention by those skilled in the art. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative work. Therefore, the present invention is not limited to the above embodiments, and improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. A method for preparing a flexible optical storage device using a two-dimensional material, characterized in that: The specific steps are: (1) Using flexible materials as substrates; (2) depositing a layer of oxide material on the substrate; (3) Transferring the two-dimensional semiconductor material to a substrate; (4) forming metal electrodes at both ends of the two-dimensional semiconductor material; (5) Spin coating a layer of organic matter on the material obtained in step (4); (6) Transferring a layer of BN material onto the organic matter; (7) Finally, a layer of ITO electrode material is deposited on the BN material; The two-dimensional semiconductor material is one of MoS2, MoSe2, WS2, WSe2, and black phosphorus, and the thickness of the two-dimensional semiconductor material is a single atomic layer.

2. The method according to claim 1, characterized in that The flexible material described in step (1) is selected from one of polyimide, polyethylene terephthalate and polyethylene naphthalate, and has a thickness of 10-300 mm.

3. The method according to claim 2, characterized in that The oxide material described in step (2) is selected from one of SiO2 and Al2O3, and has a thickness of 20-300nm.

4. The method according to claim 1, characterized in that: The metal electrode material described in step (4) is a Ti / Au or Cr / Au metal layer with a thickness of 10-200 nm.

5. The method according to claim 4, characterized in that The organic matter described in step (5) is a 1,4-bis(4-methylstyrene)benzene compound with a thickness of 1-10 nm.

6. The method according to claim 5, characterized in that The thickness of the BN material described in step (6) is 10-100 nm.

7. The method according to claim 6, characterized in that The thickness of the ITO electrode material described in step (7) is 50-100 nm.

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