Photoelectric detector based on anisotropic photo-thermoelectric material, preparation method and encryption method

Abstract

The invention belongs to the technical field of information encryption, and discloses a photoelectric detector based on an anisotropic photo-thermoelectric material, a preparation method and an encryption method, the prepared photoelectric detector is very small in size and suitable for miniaturization application, the material can be conveniently integrated into miniature electronic equipment, the integration level of the equipment can be improved, and the cost can be reduced. The material has remarkable advantages in the field of microelectronics, especially in the aspects of reducing the size of a device and improving the integration level. The photoelectric detector based on the anisotropic photo-thermoelectric material generally has high sensitivity, is beneficial to detection of weak optical signals, has excellent photoelectric conversion performance, and can realize efficient photoelectric detection. According to the encryption method provided by the invention, through diversified combinations of the preset polarization angles and positions, different information can correspond to different polarization angle and position combinations, so that the system has very high flexibility and expandability, and the generated secret key has high complexity and uniqueness.

Description

Technical Field

[0001] The present invention belongs to the technical field of information encryption, and in particular relates to a photoelectric detector based on anisotropic photothermoelectric materials, a preparation method and an encryption method. Background Art

[0002] Compared with traditional materials, high-performance low-dimensional thermoelectric materials have attracted extensive attention due to their high speed, economy and scalability. In particular, one-dimensional materials experience enhanced boundary scattering at their large boundary interfaces due to the sharp reduction in their size, which changes their low-frequency acoustic modes, thus significantly affecting their thermal conductivity and improving the performance of photothermoelectric devices. As a typical quasi-one-dimensional photothermoelectric material, Nb3Se 12 The I lattice structure shows chain-like features and undergoes two structural phase transitions at low temperatures, leading to unusual behaviors in physical properties such as thermal conductivity, dielectricity, and infrared absorption. In addition, the increase in the lateral to longitudinal ratio of the one-dimensional material gives it an excellent response to polarized light.

[0003] With the rapid development of information technology, although informatization has brought great convenience to our daily lives, the rapid spread of information has also exacerbated information security issues, which not only affect the daily lives of ordinary people, but also have a profound impact on key areas such as politics, economy and military. Therefore, it is urgent to develop new methods that can achieve high-level information encryption. Summary of the invention

[0004] The purpose of the present invention is to overcome the above shortcomings and provide a photodetector, preparation method and encryption method based on anisotropic photothermoelectric materials, which realizes optical imaging by dynamically modulating the photothermoelectric current according to the polarization state, thereby converting the encrypted information into a recognizable polarization state. This method of combining high-capacity information transmission with complex encryption technology is of great significance for meeting the growing demand for secure data communication.

[0005] In order to achieve the above object, the present invention adopts the following technical solution:

[0006] In a first aspect, the present invention provides a method for preparing a photoelectric detector based on anisotropic photothermoelectric materials, comprising the following steps:

[0007] Get the raw materials and convert Nb3Se 12 I. The crystal raw material is vacuum-sealed and finally grown to obtain anisotropic photothermoelectric materials;

[0008] The anisotropic photothermoelectric material is peeled off onto a silicon oxide wafer, a photoresist is coated on the surface of the anisotropic photothermoelectric material on the silicon oxide wafer, and a hollow pattern with a double-terminal electrode is photoetched on the photoresist;

[0009] The Cr layer and Au layer of required thickness are deposited on the silicon oxide wafer, and after peeling, the Nb3Se based 12 I Nanowire Photodetector.

[0010] A further improvement of the present invention is that Nb3Se 12 The raw materials of I crystals are Nb powder, Se powder and I2 crystals with a stoichiometric purity of 99.999%, and 2mg / cm 3 The I2 acts as a transport agent;

[0011] Nb3Se 12 I crystal raw material is placed in a quartz tube and sealed with vacuum, the vacuum degree is 5×10 -4 Pa;

[0012] When growing, containing Nb3Se 12 One end of the I crystal raw material is the evaporation end, and the other end is the growth end. The temperatures of the evaporation end and the growth end are set to 600°C and 480°C respectively. The heating rate from room temperature is 1.3°C / min, and the growth time is 14 days to complete the preparation of anisotropic photothermoelectric materials.

[0013] A further improvement of the present invention is that a 5 nm Cr layer and a 60 nm Au layer are deposited on the oxidized silicon wafer using a resistive thermal evaporation technique.

[0014] A further improvement of the present invention is that, during stripping, the deposited silicon oxide wafer is immersed in an acetone solution to separate the photoresist from the silicon oxide wafer, and then the silicon oxide wafer is taken out and immersed in isopropanol to remove the acetone, and the silicon oxide wafer is rinsed with deionized water to obtain a Nb3Se based 12 I Nanowire Photodetector.

[0015] In a second aspect, the present invention provides a photoelectric detector based on anisotropic photothermoelectric materials, which is prepared by a method for preparing a photoelectric detector based on anisotropic photothermoelectric materials.

[0016] In a third aspect, the present invention provides an encryption method for a photoelectric detector based on anisotropic photothermoelectric materials, comprising the following steps:

[0017] Preset the polarization angle corresponding to each information, and preset the position and polarization angle of the laser according to the required information;

[0018] According to the preset laser position and polarization angle, the half-wave plate is used to align the laser beam to the Nb3Se 12 I nanowire photodetector is irradiated to form a corresponding polarization state on the surface of the photodetector, and the photocurrent changes at different positions and the photocurrent changes at different polarization angles are obtained;

[0019] The photocurrent changes at different positions and the photocurrent changes at different polarization angles are fitted as the key of the photodetector.

[0020] A further improvement of the present invention is that the specific method of presetting the polarization angle corresponding to each information is as follows:

[0021] According to the required preset laser position and polarization angle, the photocurrent values ​​generated at different positions are fitted, and each degree of the polarization angle from 0 to 90 degrees is assigned an ASCII code.

[0022] A further improvement of the present invention is that the photocurrent change at different positions is achieved by adjusting the position of the laser, thereby adjusting the incident position of the incident light, and irradiating the Nb3Se with incident light at different incident positions. 12 I nanowire photodetector, and obtain the photocurrent changes at different positions.

[0023] A further improvement of the present invention is that the photocurrent change under different polarization angles is achieved by adjusting the half-wave plate to control the polarization angle of the incident light. 12 I nanowire photodetector, and obtain the photocurrent changes at different polarization angles.

[0024] A further improvement of the present invention is to fit the photocurrent changes at different positions and the photocurrent changes at different polarization angles as the key of the photodetector. The specific method is as follows:

[0025] While adjusting the laser position, the polarization angle of the laser is continuously adjusted through the half-wave plate to make the Nb3Se 12 On the photodetector of the I nanowire, the output photocurrent value along the straight light trajectory is kept consistent, so as to obtain the fitted photocurrent response curve. The photocurrent change relationship at different positions under incident light of different polarization angles is used as the Nb3Se 12 I The key to nanowire photodetectors.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The Nb3Se prepared by the present invention 12 The photodetector of I nanowire is a material based on a quasi-one-dimensional nanowire structure, which is very small and suitable for miniaturized applications. This material is easy to integrate into microelectronic devices, which helps to improve the integration of the device. This material has shown significant advantages in the field of microelectronics, especially in reducing device size and improving integration. The photodetector based on anisotropic photothermoelectric materials of the present invention usually has high sensitivity, is conducive to detecting weak light signals, and has excellent photoelectric conversion performance, and can achieve efficient photoelectric detection.

[0028] The encryption method of the present invention presets a variety of combinations of polarization angles and positions. Different information can correspond to different polarization angle and position combinations, so that the system has high flexibility and scalability. The generated key has high complexity and uniqueness and is difficult to be cracked. By selecting a specific polarization angle and position combination, the system can effectively distinguish and resist noise and interference in the environment, thereby improving the reliability of encryption. The encryption method of the present invention is based on Nb3Se 12 The photodetector of nanowires has high sensitivity and can accurately detect weak photocurrent changes to ensure the accuracy of data in the encryption process. The photodetector with nanowire structure can achieve miniaturization and high integration, which is helpful to deploy encryption systems in compact spaces. The present invention forms a key by laser irradiation of photothermoelectric materials and adopts a dual collaborative encryption principle, which significantly improves the security of information. The information decryptor must simultaneously master the photothermoelectric properties of the material and the precise matching relationship of the polarization angle in order to correctly parse the polarization angle information in the encrypted information. This encryption method makes it extremely difficult to read unauthorized information and effectively prevents illegal access and leakage of information. The present invention has important application prospects in the field of information security, especially in microelectronic devices that require high security and high integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The figure is a flow chart of the preparation of a photoelectric detector based on anisotropic photothermoelectric materials in the present invention;

[0030] Figure 2 This is a flow chart of the encryption method of the photoelectric detector in the present invention;

[0031] Figure 3 The photothermoelectric material Nb3Se prepared in Example 1 of the present invention 12 Optical image of I crystal.

[0032] Figure 4 The Nb3Se based 12 Device structure diagram of the two-terminal photodetector of I.

[0033] Figure 5 Graph showing the relationship between the photocurrent of the photodetector prepared in Example 1 of the present invention and the polarization angle of the incident laser.

[0034] Figure 6 1 is a photocurrent response curve generated by the device being illuminated by a straight light track in Example 1 of the present invention.

[0035] Figure 7 This is a photocurrent response curve generated by irradiating the device with a straight light trajectory fitted by dynamically changing the polarization angle in Example 1 of the present invention.

[0036] Figure 8 Schematic diagram of the device for the thermoelectric and polarization collaborative encryption and decryption process in Example 1 of the present invention.

[0037] Fig. 9 This is the encryption and decryption process of hidden information in Example 1 of the present invention. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0041] See also Figure 1 , a method for preparing a photoelectric detector based on anisotropic photothermoelectric materials comprises the following steps:

[0042] S1, obtain Nb3Se 12 I crystal raw material, Nb3Se 12 The I crystal raw material is vacuum-sealed in a tube and finally grown to obtain anisotropic photothermoelectric materials.

[0043] S2, peeling the anisotropic photothermoelectric material onto a silicon oxide wafer, coating a photoresist on the surface of the anisotropic photothermoelectric material on the silicon oxide wafer, and photoetching a hollow pattern with a double-terminal electrode on the photoresist.

[0044] S3, depositing a Cr layer and an Au layer of the required thickness on the silicon oxide wafer, and after peeling off, obtaining a Nb3Se based 12I Nanowire Photodetector.

[0045] See also Figure 2 , an encryption method for a photoelectric detector based on anisotropic photothermoelectric materials, comprising the following steps:

[0046] S1, preset the polarization angle corresponding to each information, and preset the position and polarization angle of the laser according to the required information.

[0047] S2, according to the preset laser position and polarization angle, is matched to the Nb3Se based 12 The photodetector of the I nanowire is irradiated to form a corresponding polarization state on the surface of the photodetector, and the photocurrent changes at different positions and the photocurrent changes at different polarization angles are obtained.

[0048] S3, fitting the photocurrent changes at different positions and the photocurrent changes at different polarization angles as the key of the photodetector.

[0049] A photoelectric detector based on anisotropic photothermoelectric material is prepared by a method for preparing a photoelectric detector based on anisotropic photothermoelectric material.

[0050] Embodiment 1:

[0051] A method for preparing a photoelectric detector based on anisotropic photothermoelectric materials comprises the following steps:

[0052] Step 1: synthesize anisotropic photothermoelectric materials.

[0053] Weighing: Weigh 1g, 3.6g, and 0.6g of 99.999% pure Nb powder, Se powder, and I2 crystals respectively as synthetic Nb3Se 12 I crystal raw materials.

[0054] Sealing tube: Mix the weighed raw material powders and place them in a single-end sealed quartz tube with an inner diameter of 2 cm and a length of 20 cm. Then install the quartz tube on a vacuum tube sealing machine and wait until the pressure reaches 5×10 -4 After Pa, it is sealed and melted by high-temperature sintering quartz tube.

[0055] Growth: Place the high-temperature sealed vacuum quartz tube in a dual-temperature zone tube furnace, with one end containing the raw material placed at the evaporation end and the other side placed at the growth end. The temperatures of the evaporation end and the growth end are set to 600°C and 480°C respectively, with a heating rate of 1.3°C / min and a growth time of 14 days to complete the synthesis of anisotropic photothermoelectric materials. The crystal material of the anisotropic photothermoelectric material obtained after growth is as follows Figure 3 shown.

[0056] Step 2: Photolithography of a two-terminal electrode based on anisotropic photothermoelectric materials.

[0057] The anisotropic photothermoelectric material obtained in step 1 was placed on a transparent tape and prepared on a silicon oxide wafer with a thickness of 285 nm by mechanical peeling. Subsequently, AZ5214 photoresist was spin-coated on the silicon oxide wafer, and a hollow pattern with a double-terminal electrode was produced by maskless photolithography.

[0058] Step three, prepare a double-terminal photodetector.

[0059] A 5 nm Cr layer and a 60 nm Au layer were deposited on an oxidized silicon wafer using resistive thermal evaporation technology. The deposition rates were and Finally, the deposited silicon oxide wafer was immersed in a 50-degree acetone solution for 2 hours, and then the evaporated silicon oxide wafer immersed in acetone was gently blown with a rubber-tipped dropper to separate the photoresist from the silicon oxide wafer. Then the silicon oxide wafer was taken out and immersed in isopropanol for 1 minute to remove the acetone, and then the silicon oxide wafer was rinsed with deionized water to obtain Nb3Se based 12 I nanowire photodetector, its device structure is shown in the figure Figure 4 shown.

[0060] Embodiment 2:

[0061] The encryption method of the photoelectric detector based on anisotropic photothermoelectric material comprises the following steps

[0062] Step 1: preset the polarization angle corresponding to each information, and preset the position and polarization angle of the laser according to the required information.

[0063] According to the required preset laser position and polarization angle, the photocurrent values ​​generated at different positions are fitted, and each degree of the polarization angle from 0 to 90 degrees is assigned an ASCII code.

[0064] Step 2: According to the preset laser position and polarization angle, the laser is aligned to the Nb3Se based laser beam through a half-wave plate. 12 The photodetector of the I nanowire is irradiated to form a corresponding polarization state on the surface of the photodetector, and the photocurrent changes at different positions and the photocurrent changes at different polarization angles are obtained.

[0065] The laser system uses a 532nm wavelength laser by placing a half-wave plate in the incident light path.

[0066] 1. Control the laser incident position and obtain the photocurrent change curve caused by different polarization angles

[0067] By rotating the half-wave plate, the polarization direction of the laser is dynamically adjusted, and the relationship between the incident laser polarization angle and the photocurrent is precisely controlled. For relevant data and diagrams, see Figure 5 .

[0068] 2. Remove the half-wave plate and adjust the laser incident position to obtain the photocurrent changes at different positions.

[0069] By moving the laser source, the laser is irradiated to the Nb3Se along a straight path. 12 The photocurrent response curve is recorded on the photodetector of the nanowire. Figure 6 As displayed.

[0070] 3. While moving the laser, adjust the position of the half-wave plate to compensate for the photocurrent change caused by the movement of the laser so that the photocurrent generated by it remains constant, thereby obtaining the fitted photocurrent response curve, which shows the photocurrent with the same value, such as Figure 7 shown.

[0071] Step three, fitting the photocurrent changes at different positions and the photocurrent changes at different polarization angles as the key of the photodetector.

[0072] When the photocurrent value is the same, the compensation polarization angles corresponding to different incident positions are obtained. Different polarization angles are respectively corresponded to different ASCII codes, and information is hidden in the optical image in this way, as shown in Table 1.

[0073] Table 1 The numerical table of ASCII codes corresponding to polarization angles

[0074]

[0075] like Figure 8 As shown, in the present invention, the "XDU" image encapsulates 30 different polarization states through polarization compensation technology, so that complex information is hidden in the image.

[0076] Embodiment 3:

[0077] The plaintext is encrypted using a symmetric encryption strategy. The specific process is as follows:

[0078] Determine the plain text: the information to be encrypted "WILEY".

[0079] Encryption: Input the plain text and key into the encryption algorithm to generate ciphertext. Ciphertext is the encrypted data and cannot be read directly.

[0080] For the "WILEY" information that needs to be encrypted for transmission, its five ASCII letters "W", "I", "L", "E" and "Y" correspond to polarization angles of 52°, 38°, 41°, 34° and 54° respectively. The specific polarization angle polarization state encoding obtained from the "XDU" image through polarization compensation technology is associated with the five angles of 52°, 38°, 41°, 34° and 54° respectively.

[0081] According to the five angles of 52 degrees, 38 degrees, 41 degrees, 34 degrees and 54 degrees, the half-wave plate is aligned to the Nb3Se 12 I nanowire photodetector is irradiated to form a corresponding polarization state on the surface of the photodetector, and the photocurrent changes at different positions and the photocurrent changes at different polarization angles are obtained;

[0082] The photocurrent changes at different positions and the photocurrent changes at different polarization angles are fitted as the key of the photodetector.

[0083] The key to decryption is to exploit the coupling between the thermoelectric and polarization properties of photothermoelectric materials. For example, in a scenario where Sophia knows the location of a specific encrypted message, she can use the relationship between the photothermoelectric properties and polarization fitting as the key to decrypt and reveal the "WILEY" message hidden in the ordinary "XDU" image. From Bob's perspective, the image may only appear as a regular image obtained by a computer or other detector.

[0084] In addition, if Fig. 9 As shown in the figure, the method of the present invention can also be extended to general imaging technology. First, the conventional single-point imaging result is processed by using the thermoelectric properties, and then the polarization state is adjusted to compensate, so as to hide information in the ordinary imaging result on the surface. This method allows a large amount of information to be encoded in a single image. 12 The ultra-wideband detection capability of I materials, which is not limited by band gap, significantly enhances the capacity and security of data transmission. The present invention is expected to promote the widespread application of anisotropic photothermoelectric devices in the fields of information encryption and anti-counterfeiting technology.

[0085] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a photoelectric detector based on anisotropic photothermoelectric materials, characterized in that: The following steps are involved: Obtaining Nb3Se 12 I crystal raw material, Nb3Se 12 I. The crystal raw material is vacuum-sealed and finally grown to obtain anisotropic photothermoelectric materials; The anisotropic photothermoelectric material is peeled off onto a silicon oxide wafer, a photoresist is coated on the surface of the anisotropic photothermoelectric material on the silicon oxide wafer, and a hollow pattern with a double-terminal electrode is photoetched on the photoresist; The Cr layer and Au layer of required thickness are deposited on the silicon oxide wafer, and after peeling, the Nb3Se based 12 I Nanowire Photodetector.

2. The method for preparing a photoelectric detector based on anisotropic photothermoelectric materials according to claim 1, characterized in that: Nb3Se 12 The raw materials of I crystals are Nb powder, Se powder and I2 crystals with a stoichiometric purity of 99.999%, and 2mg / cm 3 The I2 acts as a transport agent; Nb3Se 12 I crystal raw material is placed in a quartz tube and sealed with vacuum, the vacuum degree is 5×10 -4 Pa; When growing, containing Nb3Se 12 One end of the I crystal raw material is the evaporation end, and the other end is the growth end. The temperatures of the evaporation end and the growth end are set to 600°C and 480°C respectively. The heating rate from room temperature is 1.3°C / min, and the growth time is 14 days to complete the preparation of anisotropic photothermoelectric materials.

3. The method for preparing a photoelectric detector based on anisotropic photothermoelectric materials according to claim 1, characterized in that: A 5nm Cr layer and a 60nm Au layer were deposited on the oxidized silicon wafer using resistive thermal evaporation technology.

4. The method for preparing a photoelectric detector based on anisotropic photothermoelectric materials according to claim 1, characterized in that: During stripping, the deposited silicon oxide wafer is immersed in an acetone solution to separate the photoresist from the silicon oxide wafer. Then the silicon oxide wafer is taken out and immersed in isopropanol to remove the acetone. After the silicon oxide wafer is rinsed clean, the Nb3Se based 12 I Nanowire Photodetector.

5. A photoelectric detector based on anisotropic photothermoelectric material, characterized in that: The photoelectric detector is prepared by the preparation method of the anisotropic photothermoelectric material according to any one of claims 1 to 4.

6. An encryption method for a photoelectric detector based on anisotropic photothermoelectric materials, characterized in that: The following steps are involved: Preset the polarization angle corresponding to each information, and preset the position and polarization angle of the laser according to the required information; According to the preset laser position and polarization angle, the half-wave plate is used to align the laser beam to the Nb3Se 12 I nanowire photodetector is irradiated to form a corresponding polarization state on the surface of the photodetector, and the photocurrent changes at different positions and the photocurrent changes at different polarization angles are obtained; The photocurrent changes at different positions and the photocurrent changes at different polarization angles are fitted as the key of the photodetector.

7. The encryption method of the photoelectric detector based on anisotropic photothermoelectric material according to claim 6, characterized in that: The specific method of presetting the polarization angle corresponding to each information is as follows: According to the required preset laser position and polarization angle, the photocurrent values ​​generated at different positions are fitted, and each degree of the polarization angle from 0 to 90 degrees is assigned an ASCII code.

8. The encryption method of the photoelectric detector based on anisotropic photothermoelectric material according to claim 6, characterized in that: The photocurrent change at different positions is achieved by adjusting the position of the laser, thereby adjusting the incident position of the incident light, and irradiating Nb3Se with incident light at different incident positions. 12 I nanowire photodetector, and obtain the photocurrent changes at different positions.

9. The encryption method of the photoelectric detector based on anisotropic photothermoelectric material according to claim 6, characterized in that: The change of photocurrent under different polarization angles is achieved by adjusting the half-wave plate to control the polarization angle of the incident light. 12 I nanowire photodetector, and obtain the photocurrent changes at different polarization angles.

10. The encryption method of the photoelectric detector based on anisotropic photothermoelectric material according to claim 6, characterized in that: The steps are to fit the photocurrent changes at different positions and the photocurrent changes at different polarization angles as the key of the photodetector. The specific method is as follows: While adjusting the laser position, the polarization angle of the laser is continuously adjusted through the half-wave plate to make the Nb3Se 12 On the photodetector of the I nanowire, the output photocurrent value along the straight light trajectory is kept consistent, so as to obtain the fitted photocurrent response curve. The photocurrent change relationship at different positions under incident light of different polarization angles is used as the Nb3Se 12 I The key to nanowire photodetectors.

Images