Chalcogenide glass, method for preparing same and optical element

Abstract

The application provides a chalcogenide glass, a preparation method thereof and an optical element. The chalcogenide glass comprises the following components in terms of mole percentage: As: 20-40%, preferably 25-35%; Se: 30-50%, preferably 33-45%; Te: 10-30%, preferably 10-20%; Ge: 5-20%, preferably 5-15%; Sb: 1-15%, preferably 1-10%; Sn: 0-10%, preferably 0-8%. The chalcogenide glass has high refractive index at 10 microns, high transition temperature, wider and better infrared transmission band, less impurity absorption peak, lower refractive index temperature coefficient, lower cost and excellent optical performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of optical glass, and relates to a chalcogenide glass and a preparation method and an optical element thereof. BACKGROUND

[0002] Chalcogenide glass is a kind of infrared optical glass material, which is mainly an amorphous material formed by taking S, Se and Te as a base and introducing other network-forming elements such as Ge, Sb and As. The chalcogenide glass has a wide infrared atmospheric transmission window, and has the advantages of simple processing method, low material cost and batch molding production compared with germanium single crystal. At present, the refractive index of most chalcogenide glass materials is concentrated in 2.4-2.8, and the market demand for chalcogenide glass is increasing, but the chalcogenide glass with a refractive index greater than 2.9 on the market has the disadvantages of high production cost or poor optical performance, and cannot be widely promoted in commercial applications.

[0003] CN115196875A discloses a high-refractive-index Ge-Ga-Sb-Se-Te chalcogenide glass and a preparation method and application thereof. The glass has a large absorption peak at 10 microns, and the transmittance also sharply decreases at 11 microns, which will cause poor MTF imaging in lens design. The use of a large amount of noble metal elements such as Ge and Te will result in high production cost, which affects commercial use.

[0004] CN104402220A discloses a chalcogenide optical glass, which has a glass system of Ga-Ge-S-Te, and the raw materials are environmentally friendly, and the refractive index is 2.7-3.6. However, the system contains S element, which will cause high vapor pressure in the vacuum sealed space during glass melting, resulting in explosion danger, and the introduction of S element will make the chemical stability of the chalcogenide glass worse. SUMMARY

[0005] The invention addresses the problem

[0006] In view of the problems in the prior art, the application first provides a chalcogenide glass. The chalcogenide glass has the characteristics of high refractive index, high transition temperature, wide infrared transmittance range, high transmittance, few impurity absorption peaks, low refractive index temperature coefficient compared with other high-refractive chalcogenide glasses, and low cost.

[0007] The application further provides a preparation method of the chalcogenide glass, which is simple and easy to implement, and the raw materials are easy to obtain, and is suitable for mass production.

[0008] The solution to the problem

[0009] The application first provides a chalcogenide glass, which comprises the following components in terms of molar percentage:

[0010] As: 20-40%, preferably 25-35%;

[0011] Se: 30-50%, preferably 33-45%;

[0012] Te: 10-30%, preferably 10-20%;

[0013] Ge: 5-20%, preferably 5-15%;

[0014] Sb: 1-15%, preferably 1-10%;

[0015] Sn: 0-10%, preferably 0-8%.

[0016] The chalcogenide glass according to the present application, wherein the refractive index of the chalcogenide glass at 10 μm is 2.90 or more.

[0017] The chalcogenide glass according to the present application, wherein the refractive index temperature coefficient of the chalcogenide glass at -40-80°C is 120 x 10 -6 / ℃ or less.

[0018] The chalcogenide glass according to the present application, wherein the transition temperature of the chalcogenide glass is 150-200°C.

[0019] The chalcogenide glass according to the present application, wherein the average infrared transmittance of the chalcogenide glass in the 8-16 μm waveband is 45% or more, and the infrared transmittance at 14.5 μm is 55% or more.

[0020] Further, the present application also provides a preparation method of the chalcogenide glass according to the present application, wherein the preparation method comprises the following steps: weighing and mixing the components of the chalcogenide glass according to the proportion, melting, cooling and solidifying, and annealing to obtain the chalcogenide glass.

[0021] The preparation method of the chalcogenide glass according to the present application, wherein the preparation method comprises the following steps:

[0022] The components of the chalcogenide glass are weighed and mixed according to the proportion to obtain a mixture, and then the mixture is packaged in a sealed container; preferably, the vacuum degree in the sealed container is 10 -5 Pa or less;

[0023] The packaged sealed container is melted, cooled and solidified, and then annealed to obtain the chalcogenide glass; preferably, the melting is carried out in a rocking furnace.

[0024] According to the preparation method, the temperature of the melting is 850-1100°C, the time of the melting is 10-48 h, and / or the temperature of the cooling and solidifying is 400-700°C.

[0025] According to the preparation method, the annealing temperature is 160-200 DEG C, and the annealing rate is -1 to -20 DEG C / h.

[0026] Further, the application also provides an optical element comprising the chalcogenide glass according to the application.

[0027] Effects of the invention

[0028] The chalcogenide glass has high refractive index at 10 microns, high transition temperature, wider and better infrared transmission band, less impurity absorption peak, lower refractive index temperature coefficient, lower cost and excellent optical performance.

[0029] Further, the preparation method of the chalcogenide glass is simple and easy to operate, raw materials are easy to obtain, and is suitable for mass production. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 The figure shows the Fourier infrared spectrum of the chalcogenide glass of Example 1.

[0031] Figure 2 The figure shows the refractive index curve of the chalcogenide glass of Example 1. DETAILED DESCRIPTION

[0032] Various exemplary embodiments, features and aspects of the present application will be described in detail below. The word "exemplary" is used herein to mean "serving as an example, instance, or illustration." Any implementation described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other implementations.

[0033] In addition, in order to better illustrate the present application, numerous specific details are given in the following detailed description. Those skilled in the art should understand that the present application can be implemented without certain specific details. In some other examples, methods, means, apparatus and steps that are well known to those skilled in the art are not described in detail in order to highlight the main idea of the present application.

[0034] Unless otherwise specified, the units used in the specification are international standard units, and the numerical values and numerical ranges appearing in the present application should be understood to include the systematic errors that are inevitable in industrial production.

[0035] In the specification, the meaning of "may" includes both the meaning of performing a certain process and the meaning of not performing a certain process.

[0036] In this specification, reference to "some specific / preferred embodiments", "other specific / preferred embodiments", "embodiments", etc. means that a particular feature (e.g. a characteristic, structure, property, and / or characteristic) described in relation to that embodiment is included in at least one embodiment described herein, and can or can not be present in other embodiments. In addition, it should be understood that the described features can be combined in any suitable manner in the various embodiments.

[0037] In this specification, a numerical range expressed using "numerical value A ~ numerical value B" means a range including the end point numerical values A, B.

[0038] The present application first provides a chalcogenide glass comprising the following components in mole percentage:

[0039] As: 20 ~ 40%, preferably 25 ~ 35%;

[0040] Se: 30 ~ 50%, preferably 33 ~ 45%;

[0041] Te: 10 ~ 30%, preferably 10 ~ 20%;

[0042] Ge: 5 ~ 20%, preferably 5 ~ 15%;

[0043] Sb: 1 ~ 15%, preferably 1 ~ 10%;

[0044] Sn: 0 ~ 10%, preferably 0 ~ 8%.

[0045] In order to obtain a high-refractive chalcogenide glass with high refractive index, high transition temperature, and high infrared transmission performance in the 2 ~ 16 μm wave band, the present application introduces Te element into the As-Se glass system to increase the refractive index of the glass, and controls the amount of Te element introduced to avoid the problem of rapid reduction of the transition temperature caused by excessive introduction of Te element, and at the same time introduces a small amount of Ge element into the glass system to adjust the transition temperature. The introduction of Ge element can further improve the transmission performance of the glass. Further, the present application preferably introduces a small amount of Sn element into the glass system, so as to improve the overall transmission rate of the glass in cooperation with the Ge element, blue shift the absorption peak while reducing absorption. In addition, the introduction of a small amount of Sb element in the glass system can improve the fining effect of the glass, improve the glass forming ability and stability of the glass.

[0046] The present application is mainly for the As-Se glass system, and introduces a certain amount of Te element and Ge element, both of which are good glass network formers. The glass network is further adjusted by the introduction of Sb element or Sb element and Sn element.

[0047] As element is a good glass coordinator, which can form stable As-Se bond with Se element to constitute the main body of the glass and improve the glass forming property. When the content of As element is too low, the glass forming property will be reduced; when the content of As element is too high, the refractive index of the glass will be affected. Therefore, the content of As element is controlled to be 20-40% in terms of mole percentage, preferably 25-35%, more preferably 25-30%, for example: 21%, 23%, 25%, 27%, 29%, 31%, 33%, 35%, 37%, 39%, etc.

[0048] Se element is a good glass coordinator, which can form strong Ge-Se bond with Ge element and strong Te-Se bond with Te element, and is also beneficial to improve the glass transition temperature and crystallization property, and the introduction of Se element can effectively improve the infrared transmittance of the glass. However, too high content of Se element will reduce the overall refractive index of the glass, and too low content of Se element will reduce the glass forming property. Therefore, the content of Se element is controlled to be 30-50% in terms of mole percentage, preferably 33-45%, more preferably 38-43%, for example: 31%, 33%, 35%, 37%, 39%, 41%, 43%, 45%, 47%, 49%, etc.

[0049] Te element is a good glass coordinator, which is mainly used to improve the viscosity and crystallization property of the glass. In the present application, if the content of Te element is too high, the glass will be easy to crystallize, and the loose structure of the glass caused by the large atomic radius of Te element will reduce the transition temperature. When the content of Te element is too low, the overall refractive index of the glass will be reduced. Therefore, the content of Te element is controlled to be 10-30% in terms of mole percentage, preferably 10-20%, more preferably 13-18%, for example: 11%, 13%, 15%, 17%, 19%, 21%, 23%, 25%, 27%, 29%, etc.

[0050] Ge element has good infrared transmittance and high coordination number, and can improve the strength and glass transition temperature of the glass. In the present application, if the content of Ge element is too high, the glass is prone to crystallization, and the glass melting is difficult. Moreover, since the amount of Te element introduced is controlled in the present application, a small amount of Ge element can achieve the effect of improving the transition temperature. However, if the content of Ge element is too low, the glass forming performance of the glass body will be reduced, and the glass transition temperature will be greatly reduced, which cannot achieve the expected effect. In addition, the reduction of the amount of Ge element introduced helps to control the cost of the glass. Therefore, the content of Ge element is controlled to be 5-20% in terms of mole percentage, preferably 5-15%, more preferably 5-10%, for example: 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, etc.

[0051] Sb element can improve the fining effect of the glass, reduce the interference of bubbles, and improve the stability of the glass. In the present application, if the content of Sb element is too high, the difficulty of glass melting will increase. If the content of Sb element is too low, the fining effect and the effect of reducing bubbles of the glass cannot be achieved. Therefore, the content of Sb element is controlled to be 1-15% in terms of mole percentage, preferably 1-10%, more preferably 1-5%, for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, etc.

[0052] Sn element can improve the overall transmittance of the glass in cooperation with Ge element, blue shift the absorption peak and reduce the absorption. Moreover, Sn element has a large ion polarizability, which can cooperate with Te element to improve the refractive index of the glass. If the content of Sn element is too high, the glass forming performance will be reduced. Therefore, the content of Sn element is controlled to be 0-10% in terms of mole percentage, preferably 0-8%, more preferably 0-5%, for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, etc.

[0053] In the present application, the refractive index of the chalcogenide glass at 10 μm is 2.90 or more; the refractive index temperature coefficient of the chalcogenide glass is 120×10 -6 / ℃ or less; the glass transition temperature of the chalcogenide glass is 150-200℃; the average infrared transmittance of the chalcogenide glass in the 8-16 μm wave band is 45% or more, and the infrared transmittance at 14.5 μm can reach 55% or more.

[0054] The present application also provides a preparation method of the chalcogenide glass, comprising the following steps:

[0055] After the glass raw materials of each component are weighed according to the proportion, the mixture is obtained, and then the mixture is packaged in a sealed container, preferably, the vacuum degree in the sealed container is 10 -5 Pa below;

[0056] The packaged sealed container is subjected to melting, cooling and solidification, and then annealing to obtain a chalcogenide glass.

[0057] In some specific embodiments, the melting is carried out in a rocking furnace. For the rocking furnace, the present application is not particularly limited and can be selected as needed. Preferably, the rocking furnace can include a double-axis rotary heating rocking furnace and the like, wherein the sealed container is opposite to the rotation direction of the heating shaft, which is beneficial to obtain the required optical glass.

[0058] Specifically, in the present application, the temperature of the melting is 850-1100℃, the time of the melting is 10-48h; the temperature of the cooling and solidification is 400-700℃; the temperature of the annealing is 160-200℃, and the annealing rate is -1--20℃ / h.

[0059] Further, in the present application, the preparation method of the present application comprises the following steps:

[0060] 1) batching and vacuum sealing: weighing glass raw materials, the glass raw materials comprising As single element, Se single element, Te single element, Ge single element, Sb single element and optional Sn single element with a purity of ≥99.999%, and mixing the glass raw materials to obtain a mixture, and then packaging the mixture in a sealed container with a vacuum degree of 10 -5 Pa below by using oxyhydrogen flame;

[0061] 2) melting and quenching of the mixture: placing the packaged sealed container in a rocking furnace for high-temperature melting, the temperature of the melting is 850-1100℃, the time of the melting is 10-48h, and the melting process is rocked throughout to ensure uniform mixing of the raw materials; then cooling, when the melting temperature is reduced to 400-700℃, the sealed container is taken out for water cooling and solidification, and a glass semi-finished product is formed in the sealed container;

[0062] 3) annealing: placing the sealed container containing the glass semi-finished product into an annealing furnace, the temperature of the annealing is 160-200℃, and the annealing rate is -1--20℃ / h. Finally, the sealed container is taken out from the annealing furnace after the temperature is reduced to room temperature.

[0063] 4) sampling: knocking open the sealed container to obtain a chalcogenide glass.

[0064] Further, the present application also provides an optical element comprising the chalcogenide glass according to the present application.

[0065] Examples

[0066] The embodiments of the present application will be described in detail below with examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions not noted in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not noted by the manufacturer, which are all conventional products that can be obtained by purchase.

[0067] Examples 1-6

[0068] The preparation method of the chalcogenide glass of Examples 1-6 includes the following steps:

[0069] (1) Dosing and vacuum sealing: The elemental As, elemental Se, elemental Te, elemental Ge, elemental Sb and elemental Sn with purity ≥ 99.999% are weighed according to the components and molar content of each example in Table 1, and are loaded into an ampoule. The glass raw materials are mixed thoroughly to obtain a mixed material. The ampoule containing the mixed material is sealed and closed by using a hydrogen-oxygen flame after being vacuumed to 10 -5 Pa;

[0070] (2) Melting and quenching of the mixed material: The sealed ampoule is placed in the heating shaft of a double-shaft rotary swing furnace for high-temperature melting. The melting temperature is 900℃, and the melting time is 15h. The mixed material is shaken during the whole melting process to ensure uniform mixing. When the melting temperature drops to 600℃, the ampoule is taken out and placed in water for cooling and solidification. The glass semi-product is formed in the ampoule;

[0071] (3) Annealing: The ampoule containing the glass semi-product is placed in an annealing furnace. The annealing temperature is 170℃, and the annealing rate is -10℃ / h. After the temperature drops to room temperature, the ampoule is taken out from the annealing furnace;

[0072] (4) Knocking the ampoule and sampling: The ampoule is knocked to obtain the chalcogenide glass.

[0073] Comparative Example 1

[0074] The chalcogenide glass of Comparative Example 1 is prepared by using the preparation method of Examples 1-6 and according to the raw material ratio in Table 1.

[0075] Performance test

[0076] The chalcogenide glasses prepared in Examples 1-6 and Comparative Example 1 are tested for glass transition temperature (Tg), infrared transmittance, refractive index n 10μm , refractive index temperature coefficient (dn / dt) by using the test methods described below, and the results are shown in Table 1.

[0077] 1. Glass transition temperature (Tg)

[0078] The glass transition temperature Tg of the obtained sulfur-based glass was measured according to the test method of GB / T 7962.16-2010. The TMA tester of American PE Company was used.

[0079] 2, infrared transmittance, transmittance range

[0080] According to the test method of GB / T 36403-2018, the infrared transmittance and transmittance range of the glass were tested by using the Nicolet 380 type Fourier infrared spectrometer of American Thermo Fisher Company.

[0081] 3, refractive index n 10μm , refractive index temperature coefficient dn / dT (-40~80℃)

[0082] According to the test method of GB / T 34184-2017, GB / T 42657-2023, the refractive index and refractive index temperature coefficient (-40~80℃) were tested by using the SpeictroMaster UV-VIS-IR high-precision refractometer of German TRIOPTICS Company.

[0083] Table 1 Glass components and performance parameter test results of examples 1-6 and comparative example 1

[0084]

[0085] As shown in Table 1, from examples 1-3, it can be seen that with the increase of Ge element, the Tg of the whole glass becomes high, and the glass forming performance of the glass is enhanced.

[0086] From examples 1-5, it can be seen that with the increase of the proportion of Ge element, the transmittance range begins to narrow, which is due to the intrinsic absorption of Ge element at 12.8 μm, and with the increase of Ge element in the glass body, the intrinsic absorption gradually becomes obvious.

[0087] From examples 3-6, it can be seen that with the increase of Te element, the Tg of the glass body begins to decrease, which is due to the large atomic radius of Te element, which causes the structure of the glass body to become loose. The introduction of Te element can appropriately increase the refractive index of the glass, but at the same time, due to the increase of the refractive index, the overall transmittance of the glass gradually decreases.

[0088] From the comparison of examples 1 and comparative example 1 and examples 2-3, it can be seen that with the increase of Sn element, the overall transmittance of the glass body is obviously improved, and with the increase of Sn element, the refractive index becomes high, which is due to the large ionic polarization rate of Sn element, which can increase the refractive index.

[0089] It should be noted that, although the technical solutions of the present application are described with specific examples, those skilled in the art can understand that the present application should not be limited thereto.

[0090] The above has described various embodiments of the present application, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes are obvious to those skilled in the art without departing from the scope and spirit of the described embodiments. The selection of terms used herein is intended to best explain the principles, practical applications, or technical improvements in the market of the embodiments, or to enable other ordinary skilled persons in the art to understand the embodiments disclosed herein.

Claims

1. A chalcogenide glass comprising, in molar percentage, the following components: As: 20-40%; Se: 30-50%; Te: 10-30%; Ge: 5-20%; Sb: 1-15%; Sn: 1-10%; The chalcogenide glass has a refractive index of 2.90 or higher at 10 μm; The refractive index temperature coefficient of the chalcogenide glass is 120 × 10⁻⁶ °C in the range of -40 to 80 °C. -6 / ℃ below.

2. The chalcogenide glass according to claim 1, characterized in that, It consists of the following components in molar percentage: As: 25-35%; Se: 33-45%; Te: 10-20%; Ge: 5-15%; Sb: 1-10%; Sn: 1-8%.

3. The chalcogenide glass according to claim 1 or 2, characterized in that, The transition temperature of the chalcogenide glass is 150–200°C.

4. The chalcogenide glass according to claim 1 or 2, characterized in that, The chalcogenide glass has an average infrared transmittance of over 45% in the 8–16 μm band and an infrared transmittance of over 55% at 14.5 μm.

5. A method for preparing chalcogenide glass according to any one of claims 1 to 4, characterized in that, The process involves weighing and mixing the components of chalcogenide glass according to a certain ratio, melting them, cooling and solidifying them, and then annealing them to obtain chalcogenide glass.

6. The method for preparing chalcogenide glass according to claim 5, characterized in that, The preparation method includes the following steps: The components of the chalcogenide glass are weighed and mixed in proportion to obtain a mixture, which is then sealed in a sealed container. The sealed container is melted, cooled and solidified, and then annealed to obtain chalcogenide glass.

7. The preparation method according to claim 6, characterized in that, The vacuum level in the sealed container is 10. -5 Below Pa.

8. The preparation method according to claim 6, characterized in that, The smelting is carried out in a swing furnace.

9. The preparation method according to any one of claims 5 to 8, characterized in that, The melting temperature is 850–1100°C, and the melting time is 10–48 h; and / or, the cooling and solidification temperature is 400–700°C.

10. The preparation method according to any one of claims 5 to 8, characterized in that, The annealing temperature is 160–200°C, and the annealing rate is -1 to -20°C / h.

11. An optical element, characterized in that, Including chalcogenide glasses according to any one of claims 1 to 4.

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