阅读说明：本技术 大尺寸红外光学用锗窗口材料的制备装置及用其制备大尺寸红外光学用锗窗口材料的方法 (Preparation device of germanium window material for large-size infrared optics and method for preparing germanium window material for large-size infrared optics by using preparation device ) 是由 吴绍华 杨伟声 南曲哲 董汝昆 母婷婷 王元康 张二平 郭晨宇 钟荣 徐红刚 吴 于 2021-09-27 设计创作，主要内容包括：本发明公开了一种大尺寸红外光学用锗窗口材料的制备装置及用其制备大尺寸红外光学用锗窗口材料的方法,包括加热系统、隔热保温系统、转动升降装置和模具装置,所述加热系统设置在隔热保温系统内,模具装置则设置在加热系统内,模具装置的底部与转动升降装置相连,所述转动升降装置的下部从加热系统和隔热保温系统底部的中心穿过,制备时主要包括了分阶段加热步骤。解决现有大尺寸锗单晶直拉生长技术存在技术难度大、工艺过程和工艺条件难以控制,锗单晶成晶率低,后续成型加工困难,运行周期长、原料用量大、生产成本高的问题。(The invention discloses a preparation device of a large-size germanium window material for infrared optics and a method for preparing the large-size germanium window material for infrared optics by using the same. The problems of high technical difficulty, difficult control of technological process and technological conditions, low crystallization rate of the germanium single crystal, difficult subsequent forming and processing, long running period, large raw material consumption and high production cost in the conventional Czochralski growth technology of the large-size germanium single crystal are solved.)

1. The preparation device of the large-size germanium window material for the infrared optics is characterized by comprising a heating system (1), a heat insulation system (2), a rotary lifting device (3) and a die device (4), wherein the heating system (1) is arranged in the heat insulation system (2), the die device (4) is arranged in the heating system (1), the bottom of the die device (4) is connected with the rotary lifting device (3), and the lower part of the rotary lifting device (3) penetrates through the centers of the bottoms of the heating system (1) and the heat insulation system (2).

2. The apparatus for preparing a germanium window material for large-size infrared optics according to claim 1, wherein: the heating system (1) comprises an upper heater (11), a lower heater (12) and a bottom heater (13), wherein the upper heater (11) is arranged on the upper part of the inner wall of the heat insulation and preservation system (2), the lower heater (12) is arranged on the lower part of the inner wall of the heat insulation and preservation system (2), and the bottom heater (13) is arranged at the bottom of the inner cavity of the heat insulation and preservation system (2).

3. The apparatus for preparing a germanium window material for large-size infrared optics according to claim 1, wherein: the heat insulation system (2) is of a cylindrical structure.

4. The apparatus for preparing a germanium window material for large-size infrared optics according to claim 1, wherein: rotation elevating gear (3) axis of rotation (31) and tray (32) that set gradually including from the bottom up, the top of tray (32) meets with the bottom of die set (4), the interior bottom surface of die set (4) is smooth surface.

5. The apparatus for preparing a germanium window material for large-size infrared optics according to claim 1, wherein: the heating system (1), the heat insulation system (2), the rotary lifting device (3) and the die device (4) are all made of high-purity hot-pressed graphite or composite carbon-carbon composite materials.

6. The apparatus for preparing a germanium window material for large-size infrared optics according to claim 1, wherein: the heating system (1), the heat insulation system (2), the rotary lifting device (3) and the mould device (4) are all arranged in the vacuum furnace.

7. A method of preparing a large size germanium window material for infrared optics using the apparatus of any of claims 1-6, comprising the steps of:

s1, firstly, the mould device (4) is lifted to the upper heating area of the heating system (1), and then the high-purity germanium ingot is loaded into the mould device (4), wherein the loading amount is determined by the shape, thickness or size of the prepared germanium crystal material;

s2, adding a dopant according to a certain mass ratio;

s3, vacuumizing, filling protective gas, starting an upper heater (11) in a heating system (1), heating and melting the high-purity germanium ingot, cooling to a certain temperature after the high-purity germanium ingot is melted, keeping the temperature constant, stirring and shaking uniformly;

s4, a lower heater and a bottom heater in the heating system are started again, the temperature is constant after the temperature is raised to a certain temperature, and the lower heater (12) and the bottom heater (13) in the heating system (1) have temperature difference with the upper heater (11);

s5, utilizing a rotary lifting device to downwards bring the die device to a lower heating area of the heating system (1) at a constant speed of 5-40 mm/h;

s6, keeping the constant temperature of the lower heating area for 5-20 h;

s7, cooling the heating system to room temperature at the cooling rate of 3-15 ℃/h, and taking out the obtained germanium crystal after the temperature is reduced to the room temperature.

8. The method of claim 7, wherein the germanium window material comprises: the dopant in S2 is high-purityThe group A element simple substance is the mass ratio of the zone-melting germanium ingot raw material to the dopant.

9. The method of claim 7, wherein the germanium window material comprises: the protective gas in the S3 is high-purity nitrogen or argon.

10. The method of claim 7, wherein the germanium window material comprises: the temperature difference in S4 is 5-30 ℃.

Technical Field

The invention relates to the technical field of production and processing of infrared optical materials and application thereof, in particular to a device for preparing a large-size germanium window material for infrared optics and a method for preparing the large-size germanium window material for infrared optics by using the device.

Background

The germanium single crystal material has the advantages of good infrared transmission performance, higher refractive index, low dispersion, no deliquescence, high mechanical strength, good chemical stability and the like, is widely applied to infrared detection and thermal imaging systems, is one of the most ideal infrared optical materials at present, is a preferred infrared material of an optical system (8-12 mu m wave band) of a thermal imager, and is used for processing infrared optical elements such as an infrared optical lens, an infrared optical window and the like. The national autonomous controllable requirements of infrared cameras or thermal imagers applied to satellite-borne, ship-borne and aircraft-borne systems are increasing day by day, and the devices need large-size germanium optical materials for manufacturing optical elements such as infrared optical lenses, infrared optical windows and the like of optical systems of the devices.

Germanium materials applied to infrared optics, electronics and solar energy generally need to be grown into germanium single crystals, and currently, the most common growth methods of the germanium single crystals mainly comprise a CZ (Czochralski) method and a VGF (vertical gradient freeze) method. The Czochralski growth technology for growing the infrared germanium single crystal with the caliber less than 300mm is relatively mature, but the Czochralski growth technology for growing the germanium single crystal with the caliber more than 300mm is still a process bottleneck and a technical short plate for the Czochralski growth of the germanium single crystal, and limits and restricts the development and application of large-size infrared optical elements. Meanwhile, the Czochralski growth technology of the large-size germanium single crystal has the practical problems of high technical difficulty, difficult control of the technological process and technological conditions, low crystallization rate of the germanium single crystal, difficult subsequent forming and processing, long running period, large raw material consumption and high production cost.

Disclosure of Invention

The invention aims to provide a device and a method for preparing a large-size germanium window material for infrared optics, and solves the problems of high technical difficulty, difficult control of technological process and technological conditions, low crystallization rate of a germanium single crystal, difficult subsequent forming and processing, long running period, large raw material consumption and high production cost in the conventional large-size germanium single crystal straight pulling growth technology.

In order to solve the technical problems, the invention adopts the following technical scheme:

a preparation device of a large-size germanium window material for infrared optics comprises a heating system, a heat insulation system, a rotary lifting device and a die device, wherein the heating system is arranged in the heat insulation system, the die device is arranged in the heating system, the bottom of the die device is connected with the rotary lifting device, and the lower part of the rotary lifting device penetrates through the centers of the bottoms of the heating system and the heat insulation system.

As a further preferable aspect of the present invention, the heating system includes an upper heater, a lower heater, and a bottom heater, the upper heater is disposed on an upper portion of an inner wall of the thermal insulation system, the lower heater is disposed on a lower portion of the inner wall of the thermal insulation system, and the bottom heater is disposed at a bottom of an inner cavity of the thermal insulation system.

As a further preferred aspect of the present invention, the thermal insulation system has a cylindrical structure.

As a further preferable mode of the present invention, the rotary lifting device includes a rotary shaft and a tray which are sequentially arranged from bottom to top, the top of the tray is connected with the bottom of the mold device, and the inner bottom surface of the mold device is a flat smooth surface.

As a further preferred of the present invention, the heating system, the thermal insulation system, the rotary lifting device and the mold device are all made of high purity hot-pressed graphite or composite carbon-carbon composite material.

As a further preferred aspect of the present invention, the heating system, the heat insulation system, the rotary elevating device and the mold device are all disposed in a vacuum furnace.

A method for preparing a large-size germanium window material for infrared optics by using any one of the devices comprises the following steps:

s1, firstly, the mould device is lifted to the upper heating area of the heating system, and then the high-purity germanium ingot is loaded into the mould device, wherein the loading amount is determined by the shape, the thickness or the size of the prepared germanium crystal material;

s2, adding a dopant according to a certain mass ratio;

s3, vacuumizing, filling protective gas, starting an upper heater in a heating system, heating and melting the high-purity germanium ingot, cooling to a certain temperature after the high-purity germanium ingot is melted, keeping the temperature constant, and stirring and shaking uniformly;

s4, starting a lower heater and a bottom heater in the heating system again, raising the temperature to a certain temperature, and keeping the temperature constant, wherein the lower heater and the bottom heater in the heating system have a temperature difference with the upper heater;

s5, utilizing a rotary lifting device to downwards bring the die device to a lower heating area of the heating system at a constant speed of 5-40 mm/h;

s6, keeping the constant temperature of the lower heating area for 5-20 h;

s7, cooling the heating system to room temperature at the cooling rate of 3-15 ℃/h, and taking out the obtained germanium crystal after the temperature is reduced to the room temperature.

The doping agent is added according to a certain proportion, which is determined according to the required resistivity, and the proportion range is 0.5-4 mg of the raw material of 1kg zone-melting germanium ingot.

The constant temperature in step s5 is 900-950 ℃.

As a further preferred aspect of the present invention, the dopant in S2 is high purityThe group A element simple substance is the mass ratio of the zone-melting germanium ingot raw material to the dopant.

In a further preferred embodiment of the present invention, the protective gas in S3 is high-purity nitrogen or argon.

In a further preferred embodiment of the present invention, the temperature difference in S4 is 5 to 30 ℃.

Compared with the prior art, the invention can at least achieve one of the following beneficial effects:

1. the preparation device of the large-size germanium window material for infrared optics has the advantages of simple structure, simple and convenient operation and easy control.

2. The preparation method is efficient and rapid, saves raw materials, and is low in production cost, and meanwhile, the prepared germanium window material for the large-size infrared optics has good optical transmittance and optical processability, and can meet the processing and application requirements of germanium optical elements for the large-size infrared optics.

3. Meanwhile, by using the preparation method, the consumption and waste of zone-melting germanium ingot raw materials can be reduced, the utilization efficiency of the germanium raw materials is improved, the consumption of the hydroelectric power of the conventional germanium single crystal which runs for a long period in growth is reduced, the production cost is reduced, and the method has remarkable beneficial effects on resource saving, effective utilization, high-efficiency production and high-quality development.

Drawings

FIG. 1 is a schematic structural diagram of a device for preparing a large-size germanium window material for infrared optics according to the present invention.

FIG. 2 is a top view of the inventive die apparatus.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings of the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

In addition, the embodiments of the present invention and the features of the embodiments may be combined with each other without conflict.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, or orientations or positional relationships that the products of the present invention conventionally lay out when in use, or orientations or positional relationships that are conventionally understood by those skilled in the art, which are merely for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and the like are used merely to distinguish one description from another, and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

Specific example 1:

fig. 1 and 2 show a preparation device of a large-size germanium window material for infrared optics, which comprises a heating system 1, a heat insulation system 2, a rotating and lifting device 3 and a mold device 4, wherein the heating system 1 is arranged in the heat insulation system 2, the mold device 4 is arranged in the heating system 1, the bottom of the mold device 4 is connected with the rotating and lifting device 3, and the lower part of the rotating and lifting device 3 penetrates through the centers of the bottoms of the heating system 1 and the heat insulation system 2.

Specific example 2:

the present embodiment further describes the heating system 1 on the basis of the specific embodiment 1, where the heating system 1 includes an upper heater 11, a lower heater 12, and a bottom heater 13, the upper heater 11 is disposed on the upper portion of the inner wall of the thermal insulation system 2, the lower heater 12 is disposed on the lower portion of the inner wall of the thermal insulation system 2, and the bottom heater 13 is disposed at the bottom of the inner cavity of the thermal insulation system 2.

Specific example 3:

this embodiment is further described with reference to the specific embodiment 1, wherein the thermal insulation system 2 is a cylindrical structure.

Specific example 4:

the embodiment further describes the rotating and lifting device 3 on the basis of specific embodiment 1, the rotating and lifting device 3 includes a rotating shaft 31 and a tray 32 which are sequentially arranged from bottom to top, the top of the tray 32 is connected with the bottom of the mold device 4, and the inner bottom surface of the mold device 4 is a flat smooth surface.

Specific example 5:

in this embodiment, the manufacturing materials of the heating system 1, the thermal insulation system 2, the rotary lifting device 3 and the mold device 4 are further described on the basis of the specific embodiment 1, and the heating system 1, the thermal insulation system 2, the rotary lifting device 3 and the mold device 4 are all made of high-purity hot-pressed graphite or composite carbon-carbon composite material.

Specific example 6:

in this embodiment, the arrangement positions of the heating system 1, the thermal insulation system 2, the rotary lifting device 3 and the mold device 4 are further described on the basis of the specific embodiment 1, and the heating system 1, the thermal insulation system 2, the rotary lifting device 3 and the mold device 4 are all arranged in the vacuum furnace.

Specific example 7:

a method of using the apparatus of any one of embodiments 1-6 to prepare a large size germanium window material for infrared optics, comprising the steps of:

s1, firstly, the mould device 4 is lifted to the upper heating area of the heating system 1, and then the high-purity germanium ingot is loaded into the mould device 4, wherein the loading amount is determined by the shape, the thickness or the size of the prepared germanium crystal material;

s2, adding a dopant according to a certain mass ratio;

s3, vacuumizing, filling protective gas, starting an upper heater 11 in the heating system 1, heating and melting the high-purity germanium ingot, cooling to a certain temperature after the high-purity germanium ingot is melted, keeping the temperature constant, and stirring and shaking uniformly;

s4, starting a lower heater and a bottom heater in the heating system again, raising the temperature to a certain temperature, and keeping the temperature constant, wherein the lower heater 12 and the bottom heater 13 in the heating system 1 have a temperature difference with the upper heater 11;

s5, utilizing a rotary lifting device to bring the die device downwards to a lower heating area of the heating system 1 at a constant speed of 5-40 mm/h;

s6, keeping the constant temperature of the lower heating area for 5-20 h;

s7, cooling the heating system to room temperature at the cooling rate of 3-15 ℃/h, and taking out the obtained germanium crystal after the temperature is reduced to the room temperature.

Specific example 8:

this example further illustrates a method for preparing a large-size germanium window material for infrared optics based on specific example 7, which includes weighing 22kg of a surface-cleaned germanium polycrystalline raw material, loading the polycrystalline germanium raw material into a circular mold device made of high-purity graphite, adding a high-purity Sb dopant in a certain mass ratio, vacuumizing, filling high-purity argon as a protective gas, starting an upper heater to heat up, heating until the polycrystalline germanium is completely melted, cooling to a specific temperature, and shaking up at a constant temperature.

Starting a lower heater and a bottom heater, heating to a preset temperature, keeping the temperature constant for 2 hours when the temperature difference between the upper heater and the lower heater is 15 ℃, descending a circular mold device containing a polycrystalline germanium raw material into a lower heating area at a set speed of 15mm/h until the upper edge of the circular mold device is flush with the upper edge of the lower heater, and ensuring that the temperatures of the lower heater and the bottom heater are close to each other in the process; keeping the temperature for 12 hours, and turning off the power supply of the upper heater; and (3) cooling the lower heater and the bottom heater to the temperature lower than 150 ℃ at the set cooling rate of 6 ℃/h, closing a power switch and a protective gas argon, cooling to room temperature, and taking out the germanium crystal.

The obtained germanium crystal has a weight of 21.8kg, a resistivity in the range of (10-15) Ω. cm, and a conductivity type of N type. The round germanium infrared window plane optical element with the diameter of 500mm and the thickness of 20mm is obtained through optical processing such as grinding, polishing and the like, and the average transmittance of the germanium crystal material in the waveband range of 3.0-12.0 μm is 45.6%.

Specific example 9:

this example further illustrates a method for preparing a large-size germanium window material for infrared optics based on specific example 7, which includes weighing 8.6 kg of a surface-cleaned germanium polycrystalline raw material, loading the polycrystalline germanium raw material into a rectangular mold device made of high-purity graphite and having a length of 450mm and a width of 224mm, adding a high-purity Sb dopant in a certain mass ratio, vacuumizing, introducing high-purity argon as a protective gas, heating by an upper heater until the polycrystalline germanium is completely melted, cooling to a specific temperature, and shaking up at a constant temperature.

Starting a lower heater and a bottom heater, heating to a preset temperature, keeping the temperature constant for 1 hour after the temperature difference between the upper heater and the lower heater is 10 ℃, descending a die device containing a polycrystalline germanium raw material into a lower heating area at a set speed of 20mm/h until the upper edge of the die device is flush with the upper edge of the lower heater, and ensuring that the temperatures of the lower heater and the bottom heater are close to each other in the process; keeping the temperature for 10 hours, and turning off the power supply of the upper heater; and (3) cooling the lower heater and the bottom heater to the temperature lower than 150 ℃ at the set cooling rate of 10 ℃/h, closing a power switch and a protective gas argon, cooling to room temperature, and taking out the germanium crystal.

The obtained germanium crystal has weight of 7.7 kg, resistivity in the range of (12-19) omega cm, and conductivity type of N type. The germanium crystal material is optically processed by grinding, polishing and the like to obtain a rectangular germanium infrared window with the length of 440mm, the width of 220mm and the thickness of 15mm, and can be used for manufacturing an infrared optical element, and the average transmittance of the germanium crystal material in the wave band range of 3.0-12.0 mu m is 45.5%.

Specific example 10:

this example further illustrates a method for preparing a large-size germanium window material for infrared optics based on specific example 7, which includes weighing 14.6 kg of a surface-cleaned germanium polycrystalline raw material, loading the polycrystalline germanium raw material into a square mold device made of high-purity graphite, adding a high-purity Sb dopant in a certain mass ratio, vacuumizing, introducing high-purity argon as a protective gas, starting an upper heater to heat up, heating until the polycrystalline germanium is completely melted, cooling to a specific temperature, and shaking up at a constant temperature.

Starting a lower heater and a bottom heater, heating to a preset temperature, keeping the temperature constant for 1.5 hours when the temperature difference between the upper heater and the lower heater is 20 ℃, descending a die device containing a polycrystalline germanium raw material into a lower heating area at a set speed of 30 mm/h until the upper edge of the die device is flush with the upper edge of the lower heater, and ensuring that the temperatures of the lower heater and the bottom heater are close to each other in the process; keeping the temperature for 7 hours, and turning off the power supply of the upper heater; and (3) cooling the lower heater and the bottom heater to the temperature lower than 150 ℃ at the set cooling rate of 8 ℃/h, closing a power switch and a protective gas argon, cooling to room temperature, and taking out the germanium crystal.

The obtained germanium crystal has weight of 13 kg, resistivity in the range of (8-15) omega cm, and N-type conductivity. The square germanium infrared window optical element with the side length of 350 is obtained through optical processing such as grinding and polishing, and the average transmittance of the square germanium infrared window optical element in the wave band range of 3.0-12.0 mu m is 45.4%.

Specific example 11:

this example further illustrates S2 based on specific example 7, wherein the dopant in S2 is high-purityThe group A element simple substance is the mass ratio of the zone-melting germanium ingot raw material to the dopant.

Specific example 12:

in this embodiment, S3 is further described based on embodiment 7, and the shielding gas in S3 is high-purity nitrogen or argon.

Specific example 13:

this example further illustrates S4 based on the specific example 7, wherein the temperature difference in S4 is 5-30 ℃.

Although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that various changes in the embodiments and/or modifications of the invention can be made, and equivalents and modifications of some features of the invention can be made without departing from the spirit and scope of the invention.