An infrared absorption material based on doping regulation, a preparation method and an infrared detector

Abstract

The application provides an infrared absorption material based on doping regulation, a preparation method and an infrared detector. By introducing selenium atoms to replace tellurium atoms in a sodium gallium telluride material, the material is doped according to a doping ratio of 1:4 to 1:2 of atomic weight, the energy band structure and optical properties of the material are regulated, a new infrared absorption material is obtained, and the light absorption performance of the material in the infrared wave band is significantly improved. According to the component characteristics of the infrared absorption material, a specific preparation scheme is provided, the preparation is completed by grinding, secondary melting and annealing treatment of the set principle mass of sodium single substance, gallium single substance, tellurium single substance and selenium single substance, and the band gap and absorption intensity are accurately adjusted, and the symmetry and crystal stability of the material are also considered.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of infrared absorption materials, and particularly relates to an infrared absorption material based on doping regulation, a preparation method and an infrared detector. BACKGROUND

[0002] The absorption performance of existing infrared absorption materials in the short-wave infrared band (1-3 µm) still has deficiencies, which are mainly limited by factors such as material band gap matching, absorption efficiency and crystal defects. The energy of short-wave infrared photons is relatively high (about 0.41-1.24 eV), and it is required that the absorption material has a moderate band gap and excellent photoelectric conversion efficiency. However, existing materials still face challenges in practical applications. For example, HgCdTe has good band gap adjustability and absorption performance in the short-wave infrared band, but its thermal stability is poor and it is difficult to prepare; InGaAs is an important material in the short-wave infrared field, but its absorption wavelength is limited by the band gap, and it usually cannot cover the entire short-wave infrared band, and its device dark current is high. In addition, crystal defects and surface state problems significantly affect the quantum efficiency and signal-to-noise ratio performance of existing short-wave infrared materials. At the same time, the thermal effect of high-energy photons also puts higher requirements on the stability of the detector. SUMMARY

[0003] In view of this, the embodiments of the present application provide an infrared absorption material based on doping regulation, a preparation method and an infrared detector to eliminate or improve one or more defects in the prior art, and solve the problem of insufficient absorption performance of the existing infrared absorption material in the short-wave infrared band.

[0004] One aspect of the present application provides an infrared absorption material based on doping regulation, which is based on sodium gallium telluride as a basic material, uniformly introduces selenium atom doping, and selenium and tellurium are doped at a doping ratio of 1:4 to 1:2 of atomic weight.

[0005] On the other hand, the present application also provides a preparation method of an infrared absorption material, which is used to prepare the above-mentioned infrared absorption material based on doping regulation, and the method comprises the following steps:

[0006] According to the preset doping ratio, the required raw material mass of sodium, gallium, tellurium and selenium is calculated; wherein the doping ratio of selenium and tellurium is 1:4 to 1:2 of atomic weight;

[0007] The sodium, gallium, tellurium and selenium with the corresponding raw material mass are obtained, placed in an agate mortar, ground and mixed under the protection of inert gas, and the mixed sodium, gallium, tellurium and selenium are loaded into an ampoule and vacuumized;

[0008] The ampoule is placed in a tube furnace for the first melting, which includes heating to 950℃ at a heating rate of 5℃ / min, holding for 12 hours; cooling to 650℃ at a cooling rate of 10℃ / h to control the slow growth of crystals; and finally, cooling to room temperature at a cooling rate of 5℃ / h to obtain the preliminary crystal material;

[0009] The preliminary crystal material is taken out and ground into powder again, and then reloaded into the ampoule and placed in the tube furnace for the second melting, the steps of which are the same as the first melting;

[0010] The ampoule is placed in the tube furnace, heated to 400℃, and held for 12 hours to complete the annealing treatment, thereby obtaining the infrared absorption material.

[0011] In some embodiments, the selenium and tellurium are doped in the method according to a doping ratio of 1:4 in terms of atomic weight, and the mass ratio of the sodium element, the gallium element, the tellurium element, and the selenium element is 23:70:205:32.

[0012] In some embodiments, the selenium and tellurium are doped in the method according to a doping ratio of 1:2 in terms of atomic weight, and the mass ratio of the sodium element, the gallium element, the tellurium element, and the selenium element is 23:70:171:53.

[0013] In some embodiments, the mixed sodium element, gallium element, tellurium element, and selenium element are loaded into an ampoule and vacuumized to at least .

[0014] In some embodiments, the method further comprises: using a planetary ball mill to grind the sodium element, the gallium element, the tellurium element, the selenium element, or the preliminary crystal material to a particle size of less than 10μm, and the planetary ball mill uses tungsten carbide balls.

[0015] In some embodiments, the planetary ball mill uses a segmented interval grinding form, each grinding for 15 minutes with an interval of 5 minutes.

[0016] In some embodiments, during the grinding mixing process under the protection of an inert gas, the inert gas uses argon; or, the inert gas uses a mixed gas of 95% argon and 5% hydrogen.

[0017] In some embodiments, before the mixed sodium element, gallium element, tellurium element, and selenium element are loaded into an ampoule and vacuumized, the method further comprises: drying the ampoule at a temperature of 150℃ for 2 hours to remove moisture.

[0018] In another aspect, the present application also provides an infrared detector, which detects infrared light by using the infrared absorption material prepared by the preparation method of the infrared absorption material.

[0019] The present application has at least the following advantages:

[0020] The infrared absorption material based on doping regulation, the preparation method and the infrared detector provided by the present application introduce selenium atoms to replace tellurium atoms in sodium gallium telluride material, and the doping ratio is 1:4 to 1:2 according to the atomic weight, so as to regulate the energy band structure and optical properties of the material to obtain a new infrared absorption material, and significantly improve the light absorption performance in the infrared wave band. According to the component characteristics of the infrared absorption material, a specific preparation scheme is provided, which is prepared by grinding, secondary melting and annealing treatment of the set principle mass of sodium, gallium, tellurium and selenium. Not only the band gap and absorption intensity are accurately adjusted, but also the symmetry and crystal stability of the material are considered.

[0021] The additional advantages, objects, and features of the present application will be in part apparent and in part pointed out hereinafter by the description, the accompanying drawings and the appended claims. The advantages of the present application will be realized and attained by means of the instrumentalities and combinations pointed out in the description and the appended claims.

[0022] Those skilled in the art will appreciate that the objects and advantages of the present application can be realized and attained by means of the instrumentalities and combinations particularly pointed out in the following detailed description. BRIEF DESCRIPTION OF DRAWINGS

[0023] The accompanying drawings used to provide further understanding of the present application and constitute a part of the present application, and do not constitute a limitation of the present application. In the drawings:

[0024] Figure 1 The flowchart of the preparation method of the infrared absorption material according to an embodiment of the present application.

[0025] Figure 2 The original crystal structure diagram of NaGaTe2.

[0026] Figure 3 The crystal structure diagram of NaGaTe2 doped with selenium according to the selenium and tellurium atomic weight 1:4.

[0027] Figure 4 The crystal structure diagram of NaGaTe2 doped with selenium according to the selenium and tellurium atomic weight 1:2.

[0028] Figure 5 The absorption spectrum of the original crystal structure of NaGaTe2.

[0029] Figure 6 Absorption spectrum of NaGaTe2 original crystal structure.

[0030] Figure 7 Absorption spectrum of NaGaTe2 crystal structure after introducing selenium doping according to selenium and tellurium atom amount 1:4.

[0031] Figure 8 Absorption spectrum of NaGaTe2 crystal structure after introducing selenium doping according to selenium and tellurium atom amount 1:4.

[0032] Figure 9 Absorption spectrum of NaGaTe2 crystal structure after introducing selenium doping according to selenium and tellurium atom amount 1:2.

[0033] Figure 10 Absorption spectrum of NaGaTe2 crystal structure after introducing selenium doping according to selenium and tellurium atom amount 1:2. DETAILED DESCRIPTION

[0034] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the embodiments and drawings. Herein, the illustrative embodiments of the present application and their descriptions are used to explain the present application, but are not intended to limit the present application.

[0035] It should be noted that, in order to avoid the present application being obscured by unnecessary details, only the structures and / or processing steps closely related to the solutions according to the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0036] It should be emphasized that the term "comprises / comprising" as used herein indicates the presence of the stated features, elements, steps or components, but does not exclude one or more additional features, elements, steps or components.

[0037] It should be noted that, if not specifically stated, the term "connected" as used herein can not only mean direct connection, but also indirect connection with an intermediate.

[0038] Currently, the absorption performance of infrared absorption materials in the short-wave infrared (SWIR, 1-3 μm) band still cannot fully meet the needs of high-performance detectors and related optoelectronic devices. The short-wave infrared band is widely used in near-earth observation, optical fiber communication, food quality detection, biomedical imaging and other fields due to its good spectral penetration and low scattering characteristics, and puts forward the requirements of high sensitivity, high quantum efficiency, low dark current and wide spectral response for the performance of infrared absorption materials. However, the commonly used short-wave infrared absorption materials still face some challenges. For example, InGaAs detector is the mainstream material in this band, but its spectral response range is usually limited within 1.7 μm, which is difficult to cover the entire short-wave infrared range; although silicon-based materials have good integration capability, their band gap is large and the absorption efficiency is low, which limits their application in the short-wave infrared band. In addition, the crystal defects, interface states and surface recombination in the material preparation process have a significant impact on the absorption efficiency and device performance, and the thermal effect caused by high-energy short-wave infrared photons also puts higher requirements on the stability of the device. Although some new short-wave infrared materials have appeared in recent years, such as two-dimensional materials based on transition metal dichalcogenides (TMDs) and new quantum dot materials (such as PbS, PbSe quantum dots), these materials have certain advantages in response range and integration potential, but the problems of large-scale preparation and long-term stability have not been completely solved. Therefore, the development of new infrared absorption materials with excellent short-wave infrared absorption capacity is an important direction to promote the development of this field.

[0039] The present application aims to provide a kind of based on doping control's infrared absorption material optimization design method, by introducing selenium (Se) atomic doping in sodium gallium telluride (NaGaTe2) material, the energy band structure and optical properties of material are reasonably controlled.Selenium atom's electronegativity and atomic radius are close to tellurium atom, but the energy level distribution is slightly higher than tellurium atom, by replacing part of tellurium atom position, selenium doping will introduce new electronic state or adjust the distribution of existing electronic state, cause energy band gap (band gap) narrowing or produce additional local energy level, to enhance the interaction of long-wave infrared photon and material.In addition, selenium doping can improve carrier concentration and mobility, optimize the photoelectric response characteristics of material, while fine-tuning the lattice structure, reduce non-radiative recombination loss, further improve absorption efficiency.This control means makes the absorption performance of NaGaTe2 material in infrared band be significantly improved, help its application expansion in the field of photoelectric detection and energy conversion.

[0040] Specifically, one aspect of the present application provides an infrared absorption material based on doping control, which uses sodium gallium telluride as the base material and uniformly introduces selenium atomic doping. Selenium and tellurium are doped at a doping ratio of 1:4 to 1:2 based on atomic weight. The original crystal structure diagram of NaGaTe2 is as follows: Figure 2As shown, the crystal structure diagram after doping according to the atomic weight of selenium tellurium 1:4 or 1:2 is as shown in Figure 3 and Figure 4 As shown.

[0041] It is emphasized here that the present embodiment must ensure uniform distribution of doping atoms and try to maintain the symmetry of the crystal. This is to optimize the performance of the material, while reducing the adverse effects of structural mismatch and defects on the photoelectric performance of the material, the specific reasons are as follows: (1) Reduce local defect states and non-radiative recombination centers: If the distribution of doping atoms is uneven, it will lead to the formation of high concentration of doping clusters or defects in local area. These defects may introduce deep levels in the band gap, thereby forming non-radiative recombination centers, leading to increased recombination efficiency of photo-generated carriers, reducing the photoelectric conversion efficiency of the material. Uniform distribution of doping atoms helps to reduce the formation of deep level states and improve the photoelectric performance. (2) Maintain the integrity and symmetry of the crystal structure: NaGaTe2 is a crystal material, and its symmetry has an important influence on the energy band structure. If the distribution of doping atoms is uneven or destroys the symmetry of the crystal, it may cause lattice distortion, local stress concentration or symmetry reduction, which will cause distortion of the energy band structure or non-uniform change of the band gap, thereby reducing the infrared light absorption performance of the material. Maintaining the symmetry of the crystal can ensure stable energy band characteristics and is conducive to infrared light absorption. (3) Optimize the carrier transport performance: Uniform distribution of doping atoms helps to avoid local high charge concentration or potential distortion, thereby reducing charge scattering and improving the mobility and diffusion length of carriers. High mobility is crucial to improve the photoelectric conversion efficiency and response speed of the material. (4) Enhance the thermodynamic stability of the material: Uniform distribution of doping atoms can reduce the stress and energy gradient in local areas of the crystal, thereby improving the thermodynamic stability of the material and reducing the performance degradation caused by thermal carriers or long-term use. This is particularly important for applications such as infrared detectors that need to work under harsh conditions for a long time. (5) Ensure the consistency of macroscopic performance: In practical applications, materials are usually prepared into large-area or thin-film devices. Uniform distribution of doping atoms can ensure the consistency of the macroscopic performance of the material throughout the sample, avoiding device malfunction or deviation caused by local performance differences.

[0042] The present application also provides a preparation method of an infrared absorption material, which is used for preparing the above-mentioned infrared absorption material based on doping regulation, as shown in Figure 1 The method comprises the following steps S101-S105:

[0043] Step S101: Calculate the required raw material mass of sodium element, gallium element, tellurium element and selenium element according to the preset doping ratio; wherein the doping ratio of selenium and tellurium is 1:4 to 1:2 of atomic weight.

[0044] Step S102: Obtain sodium, gallium, tellurium and selenium elements of corresponding raw material quality, put them in a agate mortar, grind and mix under the protection of inert gas, and then load the mixed sodium, gallium, tellurium and selenium elements into an ampoule and vacuumize.

[0045] Step S103: Place the ampoule into a tube furnace for first melting, which includes heating to 950℃ at a heating rate of 5℃ / min, holding for 12 hours, reducing to 650℃ at a cooling rate of 10℃ / h to control slow crystal growth, and finally reducing to room temperature at a cooling rate of 5℃ / h to obtain preliminary crystal material.

[0046] Step S104: Take out the preliminary crystal material, grind it into powder again, re-load it into an ampoule, and place it into a tube furnace for second melting, which has the same steps as the first melting.

[0047] Step S105: Place the ampoule into a tube furnace, heat to 400℃, and hold for 12 hours to complete annealing treatment, thereby obtaining an infrared absorption material.

[0048] In step S101, selenium and tellurium are doped according to a doping ratio of 1:4 in terms of atomic weight, and the mass ratio of sodium, gallium, tellurium and selenium elements is 23:70:205:32. In other embodiments, selenium and tellurium are doped according to a doping ratio of 1:2 in terms of atomic weight, and the mass ratio of sodium, gallium, tellurium and selenium elements is 23:70:171:53.

[0049] For example, in NaGaTe2, the stoichiometric ratio of sodium (Na), gallium (Ga) and tellurium (Te) is 1:1:2. In the case of selenium doping, part of the tellurium is replaced by selenium, and the atomic number ratio of selenium to tellurium is 1:4. Therefore, after doping, the total atomic number of selenium and tellurium still satisfies the Te2 ratio constraint.

[0050] The atomic weight of sodium (Na) is 22.99 (about 23). The atomic weight of gallium (Ga) is 69.72 (about 70). The atomic weight of tellurium (Te) is 127.6 (about 128). The atomic weight of selenium (Se) is 78.96 (about 79).

[0051] The atomic number ratio of tellurium to selenium is 4:1, and the total doping ratio contains 4 tellurium and 1 selenium for every 5 atoms. The mass contribution ratio of tellurium and selenium is: 4 × 128 (atomic weight of tellurium): 1 × 79 (atomic weight of selenium) = 512:79. This means that in the tellurium-selenium part, the mass proportion of tellurium is 512 / (512+79)≈0.866, and the mass proportion of selenium is 79 / (512+79)≈0.134.

[0052] In step S102, the mass of sodium, gallium, tellurium and selenium is respectively weighed using a high-precision electronic balance (accuracy 0.0001 g). The purity of the raw materials used should reach the experimental requirements (usually ≥ 99.99%) to avoid the influence of impurities on the performance of the final material. The operation is carried out in a glove box protected by inert gas (such as argon or high-purity nitrogen) or an isolated environment filled with inert gas. The purity of the inert gas should reach 99.999%, ensuring that the oxygen and moisture content in the environment is extremely low (<1 ppm) to avoid oxidation of active metals such as sodium and reaction with water.

[0053] In some embodiments, during the grinding mixing process under the protection of inert gas, the inert gas is argon; or, the inert gas is a mixture of 95% argon and 5% hydrogen.

[0054] A chemical corrosion-resistant and non-reactive agate mortar and pestle is used. Agate material has good chemical inertness and mechanical stability, suitable for handling active materials. The weighed sodium, gallium, tellurium and selenium are sequentially placed in the mortar, avoiding direct contact with sodium (sodium should be mixed first). Slowly grind using a uniform force application method, ensuring uniform mixing of the materials while avoiding excessive force that can cause particles to scatter or materials to be wasted. The grinding time is adjusted according to the mixing degree requirement, generally lasting 20-30 minutes, during which the uniformity of mixing is checked regularly. During the grinding process, the uniformity of mixing can be judged by observing the color, texture and particle distribution state of the materials. If there is obvious particle agglomeration, the grinding time should be extended or the grinding force should be adjusted appropriately. During the operation, sodium has high activity and is extremely easy to react with oxygen and water, so the operation should be carried out in an inert atmosphere throughout to avoid contact with air and moisture. There is a risk of static electricity accumulation in materials, especially powdered selenium and tellurium, so anti-static gloves should be worn during operation and the workbench should be grounded. The operator should wear protective gloves, protective glasses and anti-static laboratory clothes to avoid direct contact of the materials with the skin or scattering.

[0055] In some embodiments, the method uses a planetary ball mill to grind sodium, gallium, tellurium, selenium or preliminary crystal material to a particle size below 10 μm, and tungsten carbide balls are used in the planetary ball mill. The planetary ball mill uses a segmented interval grinding form, with each grinding lasting 15 minutes and a 5-minute interval.

[0056] In some embodiments, the mixed sodium, gallium, tellurium and selenium are loaded into an ampoule and vacuumized to at least For example, high-purity quartz ampoules are selected, with smooth inner walls and no cracks, and the size is selected according to the sample amount, generally 10-15 mm in diameter and 15-20 cm in length. A high-vacuum pump (such as a turbo molecular pump or a diffusion pump) and a vacuum gauge (such as an ionization vacuum gauge) are provided to ensure that the vacuum can reach The following vacuum degree. Ampoule with absolute ethanol or acetone thoroughly clean, remove dust and impurities. In the oven at 120 °C-150 °C drying ampoule at least 2 hours, ensure that the inner wall of moisture. In a glove box or inert gas protection environment, keep the oxygen and moisture content in <1 ppm.

[0057] Further, using a non-static funnel, the mixture of sodium, gallium, tellurium, selenium is transferred to the bottom of the ampoule. Ensure that the sample filling volume accounts for 1 / 3 to 1 / 2 of the total volume of the ampoule, to avoid subsequent high temperature treatment due to thermal expansion caused by rupture. The sample should be as close to the bottom of the ampoule, to avoid the sample scattered on the wall of the tube. If the sample is a powder, gently knock the outer wall of the ampoule, so that the powder is deposited tightly. The opening of the ampoule is connected to the vacuum system with a vacuum adapter, to ensure that the connection is sealed (vacuum silicone or seal ring can be used to enhance the sealing). Open the vacuum pump to start pumping, close the other openings of the ampoule to ensure no gas leakage. Start the low vacuum pump (such as mechanical pump) for preliminary pumping, continue to pump until the vacuum degree is less than . Switch to high vacuum pump (such as turbo molecular pump), continue to pump until the vacuum degree reaches The following. In the process of vacuumizing, observe the vacuum gauge reading, at the same time check the ampoule connection for leakage (can be tested by injecting a small amount of high purity nitrogen). Keep the vacuum state for 10-20 minutes, to ensure that the vacuum degree is stable. If the vacuum degree continues to decrease, the leakage point needs to be checked and repaired.

[0058] Further, in the vacuum environment, adjust the height of the ampoule, so that the sample is located at the bottom of the tube, away from the heating area, to prevent the high temperature from affecting the sample during sealing. Use oxygen-acetylene flame or hydrogen-oxygen flame to heat the opening of the ampoule, rotate the ampoule uniformly to ensure uniform heating. When the quartz softens to a high temperature plastic state, use appropriate tools to pull and close the tube opening, forming a stable vacuum sealing point. During the cooling process, ensure that the sealed ampoule is placed vertically to avoid the sample moving due to vibration. After sealing, use a cooled vacuum gauge to detect whether the sealed part leaks. If the vacuum degree still meets the standard, the sealing is successful; if not, the sealing needs to be resealed.

[0059] In step S103, the ampoule is placed horizontally in the middle of the heating zone of the tube furnace, ensuring that it is located in the position with the most uniform temperature. Use high-temperature-resistant quartz supports or ceramic supports to fix the ampoule, to avoid the ampoule moving during heating or cooling. Close the sealing covers at both ends of the tube furnace, and connect the inert gas input and exhaust port to ensure that the gas can circulate. Adjust the inert gas flow (usually 50-100 mL / min), and flush the furnace tube with inert gas for 10-15 minutes to remove the residual oxygen and moisture in the furnace tube.

[0060] Further, the tube furnace is turned on and inert gas is kept flowing during the whole heating process. The heating rate is set to 5℃ / min on the program controller of the tube furnace. The target temperature is 950℃ and a segmented program is set to ensure a smooth heating. During the heating process, the sample in the tube is checked periodically to make sure that the ampoule is not cracked or abnormal. When the temperature reaches 950℃, the furnace temperature is kept constant and the timer starts for the 12-hour holding. During the holding, the inert gas is kept flowing to protect the sample. During the cooling process, the cooling rate is set to 10℃ / h and the temperature is slowly decreased to 650℃. This stage is for the slow growth of the crystal and by controlling the cooling rate, the crystal in the sample is encouraged to arrange in order. When the temperature decreases to 650℃, the cooling rate is adjusted to 5℃ / h and the temperature is further decreased to room temperature. During the cooling process, external vibration is avoided to prevent disturbance to the crystal growth.

[0061] In step S104, the preliminary crystal material is taken out, ground into powder again, reloaded into an ampoule and subjected to a second melting, mainly to improve the material uniformity. In the first melting process, the material performance can be unstable due to composition segregation, crystal growth defects or micro-component inhomogeneity in local areas. After the crystal is ground into a uniform powder again, the components in different areas can be mixed again, the possible chemical inhomogeneity can be eliminated and a uniform starting material can be provided for the next crystal growth. In addition, the crystal formed after the first melting can contain micro-cracks, grain boundary defects or poor grain orientation, which can affect the optical, electrical or mechanical properties of the material. By melting and slowly cooling again, the single crystal structure of the crystal can be further optimized or the grain orientation of the polycrystal can be improved, so that the crystal quality inside the material is more perfect. In the first melting process, a small amount of impurities can not be fully excluded (such as precursors not fully involved in the chemical reaction, gas inclusions, etc.), and the high-temperature process of the second melting can help to further exclude the impurities and make the material structure more pure and stable. During the first melting and cooling process, internal stress can be introduced due to the difference in thermal expansion coefficient during crystal growth or improper control of the cooling rate. Grinding into powder and melting again can "reset" the material, eliminate the stress distribution left over from the first melting process and ensure the structural stability of the final crystal material.

[0062] In this embodiment, the steps of the second melting are the same as the first melting.

[0063] In step S105, the ampoule containing the sample is placed in the middle of the heating zone of the tube furnace, ensuring that it is located in the area with the most uniform temperature. A high-temperature-resistant quartz support or ceramic bracket is used to fix the ampoule, avoiding movement of the ampoule during heating or cooling. The gas inlet and outlet of the tube furnace are connected to ensure smooth gas flow. The inert gas (such as argon) is turned on, with a flow rate of 50-100 mL / min, and the furnace tube is flushed for 10-15 minutes to remove oxygen and moisture. Ensure that a stable inert gas protection environment is formed in the furnace tube. Set the temperature rise rate to 5℃ / min and the target temperature to 400℃ on the program controller of the tube furnace. During the temperature rise process, periodically check the operation status of the temperature control system and ensure that the inert gas protection environment is stable and leak-free. When the temperature rises to 400℃, maintain it for 12 hours. Ensure that the furnace temperature fluctuation during the entire holding period does not exceed ±1℃. Check the furnace body status and inert gas flow regularly to avoid sample contamination due to gas interruption or equipment failure. After 12 hours of holding, set the cooling program with a cooling rate of 5℃ / min or lower until the temperature drops to room temperature. Natural cooling or program-controlled cooling can be used to avoid sudden cooling that may cause thermal stress damage to the ampoule or compromise the material properties. Continue to maintain the inert gas flow during the cooling process until the furnace temperature drops to room temperature, ensuring that the sample is not exposed to oxygen or moisture during the entire cooling process.

[0064] In another aspect, the present application also provides an infrared detector using the infrared absorption material prepared by the above method to detect infrared light.

[0065] The present application will be described below in conjunction with specific examples:

[0066] The present embodiment provides a method for optimizing the design of an infrared absorption material based on doping control. By introducing Se atom doping into NaGaTe2 material, the energy band structure and optical properties of the material are reasonably controlled to significantly improve its light absorption performance in the infrared waveband. The present embodiment not only allows precise adjustment of the band gap and absorption intensity, but also takes into account the symmetry and crystal stability of the material, providing a new design approach for developing high-performance infrared detector absorption materials.

[0067] The present embodiment includes the following steps: first, using NaGaTe2 material as the substrate, the crystal structure, band gap and optical properties are evaluated using first-principle calculation; then, through the doping design of replacing Te atoms with Se atoms in the material, the doping ratio range is 1:4 to 1:2, ensuring uniform distribution of the doping atoms and maintaining the crystal symmetry as much as possible; finally, the spectral properties of the material under different doping ratios are optimized and evaluated, and the enhancement effect of the optical response is verified through experiments to determine the optimal doping concentration and material design scheme.

[0068] The doping of Se atoms can change the intrinsic electronic structure of the material. The electronegativity and electron orbital energy level of Se atoms are different from those of Te atoms. The doping of Se atoms causes a redistribution of the local energy band, adjusting the relative positions of the conduction band and the valence band. After doping Se, due to its smaller atomic radius and higher orbital overlap, the chemical bonds in the crystal are restructured and the local non-uniformity of the charge distribution is affected, thereby affecting the band gap width and the optical transition probability. At the same time, the doping causes changes in the local state density of the material, increasing the number of transition states in the infrared band, further enhancing the material's ability to absorb infrared light.

[0069] Regarding The preparation of the crystal includes the following steps 1-6:

[0070] 1. Selection and proportioning of raw materials

[0071] First, high-purity (≥99.99%) Na, Ga, Te and Se elements are selected as raw materials. The mass of each raw material is calculated according to the target stoichiometric ratio, and the doping ratio is simulated as 1:4 and 1:2. When the doping ratio is 1:4, the mass ratio of Na:Ga:Te:Se is 23:70:205:32; when the doping ratio is 1:2, the mass ratio of Na:Ga:Te:Se is 23:70:171:53.

[0072] 2. Mixing and packaging of raw materials

[0073] The weighed Na, Ga, Te and Se raw materials are placed in a agate mortar and mixed under inert gas (such as argon) protection to ensure uniform distribution of each raw material. Then, the mixed raw materials are loaded into clean and dry high-purity quartz ampoule, vacuumed to better than to avoid oxidation and impurity contamination. The ampoule is sealed under vacuum to ensure good airtightness during subsequent heating.

[0074] 3. Melting and crystal growth

[0075] The sealed ampoule is placed in a tube furnace for melting treatment. The heating program is as follows: heat to 950°C at a rate of 5°C / min, maintain for 12 hours to ensure that the raw materials are fully melted and uniformly mixed; then, reduce to 650°C at a rate of 10°C / h to control the slow growth of the crystal; finally, reduce to room temperature at a rate of 5°C / h to obtain the preliminary crystal material.

[0076] 4. Optimization of doping uniformity

[0077] After cooling, the crystal material is taken out, ground into powder and mixed uniformly, then reloaded into the ampoule for secondary melting treatment. This step aims to further improve the uniform distribution of doped atoms in the crystal, ensuring better structural uniformity and consistency of the material.

[0078] 5. Annealing treatment

[0079] The treated material was placed in a tube furnace and heated to 400°C for 12 hours of annealing treatment. This annealing process helps to optimize the integrity of the crystal structure, reduce internal stress of the material, and thus improve the overall performance and stability of the material.

[0080] 6. Performance characterization

[0081] To verify the performance of the material, the phase composition and the integrity of the crystal structure of the doped crystal were confirmed by X-ray diffraction (XRD) technology; the uniformity of Se atom distribution in the material was analyzed using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS); in addition, the optical absorption performance of the material was measured using an ultraviolet-visible-infrared spectrophotometer, and the improvement effect of the infrared absorption performance was verified by combining the first-principle calculation results.

[0082] This embodiment realizes reasonable adjustment of the band gap and significantly enhances the light absorption performance in the infrared band through doping regulation, showing high directional selectivity response. In addition, this method combines theoretical calculation with experimental verification to ensure the efficiency of the design process and the feasibility of the material, providing a practical technical route for the development of infrared detection materials.

[0083] The absorption spectrum and its embedded graph of the original crystal structure of NaGaTe2 are Figure 5 and 6 The absorption spectrum and its embedded graph of the NaGaTe2 crystal structure doped with selenium according to the selenium and tellurium atom ratio of 1:4 are Figure 7 and 8 The absorption spectrum and its embedded graph of the NaGaTe2 crystal structure doped with selenium according to the selenium and tellurium atom ratio of 1:2 are Figure 9 and 10 By comparing the absorption spectra before and after doping regulation (see Figures 5-10 ), it can be clearly seen that the absorption intensity of the material in the infrared band range has been significantly improved, especially in multiple directions (such as XX, YY, ZZ), showing enhanced absorption response. This improvement effect indicates that the introduction of Se atoms effectively optimizes the optical performance of the material, enhances the response ability of the material to infrared light by adjusting the band gap and electronic structure, and provides important theoretical basis and technical support for the design and application of infrared absorption materials.

[0084] In summary, the infrared absorption material based on doping regulation, the preparation method and the infrared detector, by introducing selenium atoms to replace tellurium atoms in sodium gallium telluride material, the doping ratio is 1:4 to 1:2 according to the atomic weight, the band structure and the optical properties of the material are regulated to obtain a new infrared absorption material, which significantly improves the light absorption performance in the infrared band. According to the component characteristics of the infrared absorption material, the specific preparation scheme is provided, the sodium single element, gallium single element, tellurium single element and selenium single element with the set principle quality are ground, twice melted and annealed to complete the preparation, which not only accurately adjusts the band gap and absorption intensity, but also considers the symmetry and crystal stability of the material.

[0085] Those of ordinary skill in the art will appreciate that the various illustrative components, systems and methods described in connection with the embodiments disclosed herein can be implemented as hardware, software, or both. The particular implementation details are not regarded as limiting, for the specific implementation depends on the particular application and design constraints imposed on the overall system. Skilled artisans appreciate the design choices and modifications available to those skilled in the art and best mode can be determined in accordance with the particular application and design constraints imposed on the overall system. When implemented in hardware, the hardware can be implemented within one or more application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), appropriate firmware, plug-in cards, and / or the like. When implemented in software, the elements of the application are the program in the machine readable medium and the code segments to perform the necessary tasks. The program or code segments can be stored in one or more machine readable media, or transmitted by carrier waves.

[0086] It is to be understood that the application is not limited to the particular configurations and processes described herein and shown in the drawings, which are provided by way of example only. Detailed descriptions of known methods are omitted so as not to obscure the description of the present application. In the above-described embodiments, several specific steps are described and illustrated as examples. However, the method processes of the present application are not limited to the specific steps described and illustrated, and the order of the steps can be changed, or other steps can be added, or replaced, or eliminated, depending on the application.

[0087] In the present application, the features described and / or illustrated for one embodiment can be used in the same way or in a similar way in one or more other embodiments, and / or in combination with or instead of features of other embodiments.

[0088] The above description is merely illustrative of the application, and is not intended to limit the application. The embodiments of the application can be variously changed and modified by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the application shall fall within the scope of the application.

Claims

1. An infrared absorption material based on doping control, characterized by, The material is based on sodium gallium telluride, and uniformly introduces selenium atom doping, and the doping ratio of selenium and tellurium is 1:4 to 1:2 according to atomic weight.

2. A method for producing an infrared absorbing material, characterized by, The method for preparing the doped and regulated infrared absorption material in claim 1 comprises the following steps: According to the preset doping ratio, the required raw material mass of sodium, gallium, tellurium and selenium is calculated; wherein the doping ratio of selenium and tellurium is 1:4 to 1:2 according to atomic weight; The corresponding raw material mass of the sodium, the gallium, the tellurium and the selenium is obtained, and the sodium, the gallium, the tellurium and the selenium are mixed in a grinding mortar under the protection of inert gas, and then the mixed sodium, the gallium, the tellurium and the selenium are loaded into an ampoule and vacuumized; The ampoule is placed in a tube furnace for first melting, and the first melting comprises: heating to 950℃ at a heating rate of 5℃ / min, holding for 12 hours; reducing to 650℃ at a cooling rate of 10℃ / h to control the slow growth of the crystal; finally, reducing to room temperature at a cooling rate of 5℃ / h to obtain a preliminary crystal material; The preliminary crystal material is taken out and ground into powder again, and then loaded into the ampoule and placed in the tube furnace for second melting, and the steps of the second melting are the same as those of the first melting; The ampoule is placed in the tube furnace, heated to 400℃, and held for 12 hours to complete the annealing treatment, thereby obtaining the infrared absorption material.

3. The method for producing an infrared absorbing material according to claim 2, wherein In the method, the doping ratio of selenium and tellurium is 1:4 according to atomic weight, and the mass ratio of the sodium, the gallium, the tellurium and the selenium is 23:70:205:

32.

4. The method for producing an infrared absorbing material according to claim 2, wherein In the method, the doping ratio of selenium and tellurium is 1:2 according to atomic weight, and the mass ratio of the sodium, the gallium, the tellurium and the selenium is 23:70:171:

53.

5. The method for producing an infrared absorbing material according to claim 2, wherein The mixed sodium element, gallium element, tellurium element and selenium element are loaded into an ampoule and vacuumized to at least 10"5Pa. .

6. The method for producing an infrared absorbing material according to claim 2, wherein The method further comprises: using a planetary ball mill to grind the sodium, the gallium, the tellurium, the selenium or the preliminary crystal material to a particle size of less than 10μm, and the planetary ball mill uses tungsten carbide balls.

7. The method for producing an infrared absorbing material according to claim 6, wherein The planetary ball mill adopts a segmented interval grinding form, and each grinding is 15 minutes with an interval of 5 minutes.

8. The method for producing an infrared absorbing material according to claim 2, wherein During the mixing process under the protection of inert gas, the inert gas uses argon; or, the inert gas uses 95% argon and 5% hydrogen mixed gas.

9. The method for preparing the infrared absorbing material according to claim 2, characterized in that, Before loading the mixed sodium, the gallium, the tellurium and the selenium into the ampoule and vacuumizing, the method further comprises: drying the ampoule at a temperature of 150℃ for 2 hours to remove moisture.

10. An infrared detector, characterized by The infrared detector uses the infrared absorption material prepared by the preparation method of any one of claims 2 to 9 to detect infrared light.

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