Crystal growth control method

Abstract

The invention relates to the technical field of crystal growth, and discloses a crystal growth control method which comprises the following steps: when a crystal begins to grow, controlling a first heat exchange part to move from a first temperature cavity to a second temperature cavity at a first preset rate until a crucible is completely positioned in a heat dissipation channel of a second heat exchange part; when the crystal starts to grow, the first heat exchange part and the second heat exchange part are synchronously kept to continue heat exchange, or the first heat exchange part and the second heat exchange part are synchronously controlled to start heat exchange; and when the crucible starts to enter the second temperature cavity in the vertical direction, the heating power of the second heater is controlled to be reduced at a second preset rate, and the first heat exchange part and the second heat exchange part are synchronously kept to continue heat exchange, so that the temperature in the second temperature cavity is adjusted to be within the preset temperature range until crystal growth in the crucible is finished. The quality and the performance of the prepared crystal can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of crystal growth technology, and more particularly to methods for controlling crystal growth. Background Technology

[0002] In the process of preparing large-sized crystals using the descending method, a temperature field with a certain temperature gradient needs to be formed within the apparatus. Then, a crucible containing the raw material melt is slowly lowered, moving from a high-temperature region to a low-temperature region to achieve crystallization. Therefore, the temperature gradient during crystallization is closely related to the quality of the crystals.

[0003] Current crystal growth control methods involve setting heaters in the upper and lower temperature zones and installing cooling water channels on the crystal substrate. While these methods can control the temperature gradient, the uniformity and efficiency of heat dissipation during crystal growth still need improvement, as do the quality and performance of the crystal. Summary of the Invention

[0004] The purpose of this invention is to provide a crystal growth control method to solve the above-mentioned problems existing in crystal growth methods in related technologies.

[0005] A crystal growth control method, comprising a crystal growth apparatus including a heat preservation structure, a heating component, a crystal seat, a crucible, and a heat exchange component; the heat preservation structure having a first temperature cavity and a second temperature cavity sequentially distributed and connected from top to bottom; the heating component including a first heater fixedly disposed in the first temperature cavity and a second heater fixedly disposed in the second temperature cavity; the heat exchange component including a first heat exchange element fixedly disposed in the crystal seat and a second heat exchange element fixedly disposed in the second temperature cavity, the crystal seat being configured to move downward from the first temperature cavity to the second temperature cavity, the crystal seat and / or the first heat exchange element supporting the crucible, the first heat exchange element also being used to dissipate heat from the raw material in the crucible; the second heat exchange element having a heat dissipation channel extending vertically, the heat dissipation channel being used to accommodate the crystal seat, the first heat exchange element, and the crucible; the crystal growth control method includes:

[0006] When the molten material in the crucible begins to grow, the crucible is controlled to move from the first temperature chamber to the second temperature chamber at a first preset rate until the crucible is completely located in the heat dissipation channel of the second heat exchanger; when the molten material in the crucible begins to grow, the first heat exchanger and the second heat exchanger are kept in heat exchange simultaneously, or the first heat exchanger and the second heat exchanger are controlled to start heat exchange simultaneously.

[0007] When the crucible begins to enter the second temperature chamber along the vertical direction, the heating power of the second heater is controlled to decrease at a second preset rate, while the first heat exchanger and the second heat exchanger continue to exchange heat, so that the temperature in the second temperature chamber is adjusted to be within the preset temperature range until the crystal growth in the crucible ends.

[0008] As an alternative to the above crystal growth control method, the number of the second heat exchanger is two, and both second heat exchangers are heat exchange tubes. The heat exchange tube located above is the first heat exchange tube, and the heat exchange tube located below is the second heat exchange tube.

[0009] When controlling the second heat exchanger to perform heat exchange, a first heat exchange medium is introduced into the first heat exchange tube, and a second heat exchange medium is introduced into the second heat exchange tube simultaneously; the thermal conductivity of the first heat exchange medium is less than that of the second heat exchange medium.

[0010] When the crucible begins to enter the second temperature cavity along the vertical direction, the flow rate of the first heat exchange medium is gradually increased to a first preset flow rate, and the flow rate of the second heat exchange medium is simultaneously increased to a second preset flow rate, so that the temperature in the second temperature cavity is adjusted to be within the preset temperature range until the crystal growth in the crucible is completed.

[0011] As an alternative to the above crystal growth control method, the molten material in the crucible is CsI molten material; the first heat exchange medium is argon gas, the inlet temperature of the first heat exchange medium is 30°C, and the initial inlet flow rate of the first heat exchange medium is less than or equal to 10 L / min.

[0012] As an alternative to the above crystal growth control method, the value range of the first preset flow rate is 20L / min to 100L / min.

[0013] As an alternative to the above crystal growth control method, the first preset flow rate is 40 L / min.

[0014] As an alternative to the above crystal growth control method, the molten material in the crucible is CsI molten material; the second heat exchange medium is water, the inlet temperature of the second heat exchange medium is 30°C, and the initial inlet flow rate of the second heat exchange medium is less than or equal to 5 L / min.

[0015] As an alternative to the above crystal growth control method, the value range of the second preset flow rate is 6L / min to 30L / min.

[0016] As an alternative to the above crystal growth control method, the second preset flow rate is 40 L / min.

[0017] As an alternative to the above crystal growth control method, the first heat exchanger is a third heat exchange tube; the molten material in the crucible is CsI molten material.

[0018] When the first heat exchanger starts to exchange heat, water is introduced into the third heat exchange tube, and the water flow rate in the third heat exchange tube is controlled to be 15L / min, and the water temperature in the third heat exchange tube is controlled to be 30℃.

[0019] As an optional solution to the above crystal growth control method, the molten material in the crucible is CsI molten material;

[0020] The first preset rate ranges from 0.6 mm / h to 4 mm / h.

[0021] The second preset rate is 10W / mm;

[0022] The preset temperature range is 330℃~350℃.

[0023] Beneficial effects:

[0024] This invention provides a crystal growth control method, which includes: when the molten material in the crucible begins to grow, controlling the crucible to move from the first temperature chamber to the second temperature chamber at a first preset rate until the crucible is completely located within the heat dissipation channel of the second heat exchanger; when the molten material in the crucible begins to grow, simultaneously maintaining the first heat exchanger and the second heat exchanger to continue heat exchange, or simultaneously controlling the first heat exchanger and the second heat exchanger to begin heat exchange; when the crucible begins to enter the second temperature chamber in the vertical direction, controlling the heating power of the second heater to decrease at a second preset rate, simultaneously maintaining the first heat exchanger and the second heat exchanger to continue heat exchange, so that the temperature in the second temperature chamber is adjusted to be within a preset temperature range until the crystal growth in the crucible ends.

[0025] As the crystal growth length increases, the crystal's heat dissipation capacity decreases. Therefore, by simultaneously exchanging heat with the crystal through the first and second heat exchangers, and by controlling the heating power of the second heater to decrease at a second preset rate when the crucible begins to enter the second temperature chamber in the vertical direction, the efficiency and effect of removing latent heat and overheat from the crystal can be effectively improved compared to related technologies. Secondly, since the crucible is supported on the crystal seat, and the crystal seat, the first heat exchanger fixedly disposed on the crystal seat, and the crucible supported on the crystal seat and / or the first heat exchanger can all be accommodated in the heat dissipation channel of the second heat exchanger, when the crucible is completely located in the heat dissipation channel, the first and second heat exchangers can work together to remove heat from the center and periphery of the crystal. This not only improves the efficiency and effect of removing latent heat and overheat from the crystal, but also effectively improves the heat dissipation uniformity of the crystal. Compared to related technologies, this effectively improves the effect of maintaining the crystal growth interface at a flat or slightly concave interface, effectively improves the crystal growth driving force, and effectively improves the impurity removal ability during the crystal growth process, thereby effectively improving the quality and performance of the prepared crystal. Attached Figure Description

[0026] Figure 1 A cross-sectional view of a crystal growth apparatus provided in an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the structure of the crystal growth apparatus provided in an embodiment of the present invention;

[0028] Figure 3 This is a partial cross-sectional view of the crystal growth apparatus provided in an embodiment of the present invention;

[0029] Figure 4 A physical image of a CsI crystal prepared using the crystal growth control method and the crystal growth apparatus provided in an embodiment of the present invention;

[0030] Figure 5 A physical image of a CsI crystal prepared using only the first heat exchanger, provided as an embodiment of the present invention.

[0031] Figure 6 A line graph comparing the crystal growth length with the temperature of the second temperature cavity 4 when CsI is prepared using the crystal growth control method and the crystal growth apparatus provided in the embodiments of the present invention, and when CsI is prepared using a crystal growth apparatus with only the first heat exchanger;

[0032] Figure 7 A physical image of an AgGaS2 crystal prepared using the crystal growth control method and the crystal growth apparatus provided in an embodiment of the present invention;

[0033] Figure 8This is a physical image of an AgGaS2 crystal prepared by only setting the first heat exchanger, as provided in an embodiment of the present invention.

[0034] In the picture:

[0035] 1. Insulation shell; 11. Upper insulation barrel; 12. Upper insulation cover; 13. Lower insulation barrel; 14. Lower insulation cover; 141. Second through hole;

[0036] 2. Insulation board; 21. First through hole;

[0037] 3. First warm chamber;

[0038] 4. Second warm chamber;

[0039] 51. First heater; 52. Second heater;

[0040] 6. Crystal seat; 61. Crystal seat body; 62. Support portion;

[0041] 7. Crucible;

[0042] 8. Second heat exchange component;

[0043] 9. Lifting drive mechanism; 91. Motor; 92. Lead screw; 93. Nut; 94. Connecting rod. Detailed Implementation

[0044] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0045] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Furthermore, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0047] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0048] This invention provides a crystal growth apparatus, such as... Figure 1-3 As shown, the crystal growth apparatus includes a heat preservation structure, a heating component, a crystal seat 6, a crucible 7, and a heat exchange component. The heat preservation structure forms a first temperature cavity 3 and a second temperature cavity 4 that are distributed and connected from top to bottom. The heating component includes a first heater 51 fixedly disposed in the first temperature cavity 3 and a second heater 52 fixedly disposed in the second temperature cavity 4. The heat exchange component includes a first heat exchange element fixedly disposed in the crystal seat 6 and a second heat exchange element 8 fixedly disposed in the second temperature cavity 4. The crystal seat 6 is configured to move downward from the first temperature cavity 3 to the second temperature cavity 4. The crystal seat 6 and / or the first heat exchange element are used to support the crucible 7. The first heat exchange element is also used to dissipate heat from the raw material in the crucible 7. The second heat exchange element 8 is provided with a heat dissipation channel that runs through the vertical direction. The heat dissipation channel is used to accommodate the crystal seat 6, the first heat exchange element, and the crucible 7.

[0049] When growing a crystal using this crystal growth apparatus, the first heater 51 and the second heater 52 are controlled to operate, causing the temperature in the first temperature chamber 3 to rise to a first preset temperature and the temperature in the second temperature chamber 4 to rise to a second preset temperature. The temperature gradient within the insulation structure is a set temperature gradient. The processed raw material is vacuum-sealed and placed in the crucible 7 and moved to the first temperature chamber 3 for insulation, so that the raw material is completely transformed into molten material, and the molten material begins to grow. When the molten material in the crucible 7 begins to grow, the crucible 7 is controlled to move from the first temperature chamber 3 to the second temperature chamber 4 at a first preset rate until the crucible 7 is completely located within the heat dissipation channel of the second heat exchanger 8. When the molten material in the crucible 7 begins to grow, the first heat exchanger 8 and the second heat exchanger 8 are simultaneously kept in heat exchange, or the first heat exchanger 8 and the second heat exchanger 8 are simultaneously controlled to begin heat exchange. When the crucible 7 begins to enter the second temperature chamber 4 in the vertical direction, the heating power of the second heater 52 is controlled to decrease at a second preset rate, while the first heat exchanger and the second heat exchanger 8 continue to exchange heat simultaneously, so that the temperature in the second temperature chamber 4 is adjusted to be within the preset temperature range until the crystal growth in the crucible 7 ends.

[0050] As the crystal growth length increases, the crystal's heat dissipation capacity decreases. Therefore, the first and second heat exchangers 8 simultaneously exchange heat with the crystal. Furthermore, when the crucible 7 begins to enter the second temperature chamber 4 in the vertical direction, the heating power of the second heater 52 is controlled to decrease at a second preset rate. Compared to related technologies, this effectively improves the efficiency and effect of removing latent heat from the crystal and overheating from the melt. Secondly, since the crucible 7 is supported on the crystal seat 6, and the crystal seat 6, the first heat exchanger fixedly mounted on the crystal seat 6, and the crucible supported on the crystal seat 6 and / or the first heat exchanger... Both the first and second heat exchangers 7 can be accommodated within the heat dissipation channel of the second heat exchanger 8. When the crucible 7 is completely located within the heat dissipation channel, the first and second heat exchangers 8 can work together to remove heat from the center and periphery of the crystal. This improves the efficiency and effectiveness of removing latent heat and melt overheat, while also enhancing the uniformity of heat dissipation. Compared to related technologies, this effectively improves the ability to maintain the crystal growth interface at a flat or slightly convex interface, and enhances the impurity removal capability during crystal growth, thereby improving the quality and performance of the prepared crystal.

[0051] It is understandable that the values ​​of the first preset temperature, the second preset temperature, the first preset rate, the second preset rate, and the preset temperature range are different for different types of crystal raw materials and the size of the crystal blank to be made.

[0052] Specifically, the insulation structure includes an insulation shell 1 and a heat insulation plate 2. The heat insulation plate 2 is fixedly installed inside the insulation shell 1, and the heat insulation plate 2 divides the cavity of the insulation shell 1 into a first temperature cavity 3 and a second temperature cavity 4.

[0053] More specifically, such as Figure 1-3 As shown, the insulation shell 1 includes an upper insulation barrel 11, an upper insulation cover 12, a lower insulation barrel 13, and a lower insulation cover 14. The upper insulation barrel 11, the upper insulation cover 12, and the heat insulation plate 2 form a first temperature cavity 3, and the lower insulation barrel 13, the lower insulation cover 14, and the heat insulation plate 2 form a second temperature cavity 4. More specifically, the heat insulation plate 2 has a first through hole 21 extending in the vertical direction, which connects the first temperature cavity 3 and the second temperature cavity 4. The lower insulation cover 14 has a second through hole 141, which connects the second temperature cavity 4 to the outside.

[0054] More specifically, the upper insulation barrel 11, upper insulation cover 12, lower insulation barrel 13, lower insulation cover 14, and insulation board 2 of the insulation shell 1 are all made of alumina foam bricks. Alumina foam bricks have good thermal insulation performance and low electrical conductivity. It is understood that the materials used for the upper insulation barrel 11, upper insulation cover 12, lower insulation barrel 13, lower insulation cover 14, and insulation board 2 can be adapted to meet actual working conditions. It is also understood that the material, thickness, and vertical placement of the insulation board 2 can be adjusted adaptively according to the different sizes of crucibles 7 and crystal growth requirements; the material and thickness of the insulation shell 1 can also be adjusted adaptively according to the different sizes of crucibles 7 and crystal growth requirements. In this embodiment, the thickness of the insulation shell 1 is greater than or equal to 100 mm.

[0055] Optionally, such as Figure 1 As shown, there are at least two second heat exchange components 8, which are distributed sequentially in the vertical direction. Both of the at least two second heat exchange components 8 are heat exchange tubes. The thermal conductivity of the heat exchange medium introduced into the at least two second heat exchange components 8 gradually increases from top to bottom in the vertical direction.

[0056] By setting the number of second heat exchangers 8 to at least two, and distributing the at least two second heat exchangers 8 sequentially along the vertical direction, the efficiency and effect of removing latent heat from the crystal and overheating from the melt can be further improved. Secondly, as the crystal growth length increases, the heat dissipation capacity of the crystal decreases. Therefore, by setting the heat exchange medium introduced into the at least two second heat exchangers 8 from top to bottom along the vertical direction, the thermal conductivity of the heat exchange medium gradually increases, so that the heat removal capacity of the at least two second heat exchangers 8 can match the heat dissipation capacity of the crystal. Moreover, the cooling temperature change of the crystal is relatively gentle, and the cooling of the crystal is relatively gentle, thereby effectively avoiding crystal cracking caused by excessive cooling rate, and further improving the quality and performance of the prepared crystal.

[0057] In this embodiment, as Figure 1As shown, preferably, there are two second heat exchangers 8, with the upper one being the first heat exchanger and the lower one being the second heat exchanger. Further, the heat exchange medium introduced into the first heat exchanger is argon gas. The heat exchange medium introduced into the second heat exchanger is water. Argon gas has a lower thermal conductivity than water, resulting in a gentler cooling temperature change for the crystal. This gentler cooling effectively avoids crystal cracking caused by excessive cooling rates, further improving the quality and performance of the prepared crystal.

[0058] It is understandable that the number of second heat exchange components 8 can be adjusted to three or four, depending on the actual operating conditions. The type of heat exchange medium in each second heat exchange component 8 can also be changed according to the actual operating conditions, ensuring that the thermal conductivity of the heat exchange medium introduced into at least two second heat exchange components 8 gradually increases from top to bottom along the vertical direction.

[0059] Optionally, in this embodiment, as Figure 1 As shown, the second heat exchange component 8 is an axially spiral heat exchange tube extending in the vertical direction. It has a simple structure, is easy to manufacture and install, and effectively ensures the removal of heat generated during crystal growth.

[0060] In other embodiments, the second heat exchanger 8 may be cylindrical and have heat exchange channels formed inside.

[0061] Specifically, in this embodiment, the axial spiral heat exchange tube is exemplary in that both ends extend from the bottom of the insulation shell 1. In other embodiments, the axial spiral heat exchange tube may also be configured so that both ends extend from the outer periphery of the insulation shell 1.

[0062] Among them, such as Figure 1-3 As shown, the crystal growth apparatus also includes a lifting drive mechanism 9.

[0063] Optionally, in this embodiment, as Figure 1-3 As shown, the crystal seat 6 includes a crystal seat body 61 and a support portion 62 connected to each other. A first heat exchanger is fixedly disposed on the crystal seat body 61. The crystal seat body 61 and / or the first heat exchanger are used to support the crucible 7. The support portion 62 extends out of the second temperature chamber 4 in the vertical direction and is connected to the output end of the lifting drive mechanism 9. The lifting drive mechanism 9 is used to drive the support portion 62 to move up and down in the vertical direction. This enables the crystal seat 6, the first heat exchanger fixedly disposed on the crystal seat 6, and the crucible 7 supported on the crystal seat body 61 and / or the first heat exchanger to move up and down synchronously.

[0064] In this embodiment, as Figure 1 and Figure 2As shown, the exemplary lifting drive mechanism 9 includes a motor 91 and a lead screw assembly. The lead screw assembly includes a threaded lead screw 92 and a nut 93. The output shaft of the motor 91 is drivenly connected to the lead screw 92, and the nut 93 is fixedly connected to the support part 62 and slidably disposed in the vertical direction. This enables the synchronous vertical lifting of the first heat exchanger and the crucible 7 supported on the first heat exchanger.

[0065] Furthermore, in this embodiment, as Figure 1 and Figure 2 As shown, the exemplary configuration includes two lifting drive mechanisms 9. The nuts 93 of the two lifting drive mechanisms 9 are fixedly connected by a connecting rod 94. The support part 62 is fixedly connected to the connecting rod 94 so as to synchronously drive the support part 62 to rise and fall in the vertical direction, and to improve the stability of driving the crucible 7 to rise and fall.

[0066] In other embodiments, the lifting drive mechanism 9 may be an electric actuator, a pneumatic cylinder, or a hydraulic cylinder, which can drive the support part 62 to move up and down in the vertical direction.

[0067] Alternatively, in this embodiment, the crystal seat 61 has a receiving groove on its top surface along the vertical direction, and the first heat exchanger is fixedly received in the receiving groove. This allows the first heat exchanger to be fixedly disposed on the crystal seat 61, and enables the first heat exchanger to dissipate heat from the raw material in the crucible 7.

[0068] Understandably, when the first heat exchanger is fully housed within the receiving groove in the vertical direction, the upper surface of the crystal seat 61 in the vertical direction supports the crucible 7. When the top of the first heat exchanger in the vertical direction is flush with the upper surface of the crystal seat 61, both the crystal seat 61 and the first heat exchanger can support the crucible 7. When the top of the first heat exchanger in the vertical direction extends beyond the upper surface of the crystal seat 61, the first heat exchanger serves to support the crucible 7 and to dissipate heat from the raw material inside the crucible 7.

[0069] Alternatively, in this embodiment, the first heat exchanger is a radial spiral heat exchange tube. This has a simple structure, is easy to manufacture and install, and effectively ensures the heat generated during crystal growth is dissipated. Alternatively, the first heat exchanger may be a third heat exchange tube.

[0070] In other embodiments, the first heat exchange component may also be configured to be serpentine or the like.

[0071] In this embodiment, water is used as the heat exchange medium flowing through the third heat exchange tube. In other embodiments, argon or other gases may also be used as the heat exchange medium flowing through the third heat exchange tube.

[0072] In this embodiment, the crystal base 6 is exemplarily made of copper. This allows the first heat exchange component to perform heat exchange more effectively. It is understood that the material of the crystal base 6 can be adapted to meet actual operating conditions.

[0073] Optionally, such as Figure 3 As shown, the number of crystal seats 6, crucibles 7, and first heat exchangers are all at least two, with at least two crystal seats 6, at least two crucibles 7, and at least two first heat exchangers arranged in a one-to-one correspondence. Correspondingly, the number of first vias 21 is at least two, and the number of second vias 141 is at least two, with at least two crystal seats 6, at least two crucibles 7, at least two first heat exchangers, at least two first vias 21, and at least two second vias 141 arranged in a one-to-one correspondence. This can improve the efficiency of crystal preparation.

[0074] Optionally, in this embodiment, as Figure 1 As shown, the first heater 51 is an annular heater, and the first heater 51 has a first heating channel that runs through it in the vertical direction. The first heating channel is used to hold the crucible 7. It can uniformly heat the temperature of the first temperature chamber 3 to a first preset temperature, improve the heating uniformity, and uniformly heat the raw materials in the crucible 7 into molten material.

[0075] Further optional, such as Figure 1 As shown, the number of first heaters 51 is at least two, and the at least two first heaters 51 are spaced apart in the vertical direction. This can improve the efficiency of heating the first temperature cavity 3 to a first preset temperature. In this embodiment, as... Figure 1 As shown, the exemplary configuration includes two first heaters 51.

[0076] Further optionally, the first heater 51 is a silicon carbide rod heater; or, the first heater 51 is a silicon molybdenum rod heater, etc.

[0077] Optionally, in this embodiment, the second heater 52 is an annular heater, and the second heater 52 is provided with a second heating channel that runs through the vertical direction. The second heating channel is used to accommodate the crucible 7. It can uniformly heat the temperature of the second temperature chamber 4 to the second preset temperature, improve the heating uniformity, and further uniformly heat the raw materials in the crucible 7 into molten material.

[0078] Further optionally, the number of second heaters 52 is at least two, and the at least two second heaters 52 are spaced apart in the vertical direction. This can improve the efficiency of heating the second temperature cavity 4 to a second preset temperature. In this embodiment, as... Figure 1 As shown, the exemplary configuration sets the number of second heaters 52 to one.

[0079] Specifically, along the vertical direction, the distance between the second heater 52 and the heat insulation plate 2 is the first distance, and the distance between the second heater 52 and the inner bottom wall of the second temperature cavity 4 is the second distance.

[0080] Further optional, such as Figure 1 As shown, the first spacing is smaller than the second spacing along the vertical direction. This causes the second heater 52 to be positioned close to the first heater 51 along the vertical direction, thereby further improving the efficiency of heating the temperature inside the insulation shell 1. This allows the temperature gradient at the insulation plate 2 to quickly and efficiently reach the set temperature gradient, reducing heat loss.

[0081] In this embodiment, as Figure 1 As shown, in the exemplary arrangement along the vertical direction, the second heater 52 is located at the top of the second temperature cavity 4. In this embodiment, the first spacing may also be adapted to be greater than or equal to the second spacing according to actual working conditions.

[0082] Further optionally, the second heater 52 is a silicon carbide rod heater; or, the second heater 52 is a silicon molybdenum rod heater, etc.

[0083] Specifically, both the first heater 51 and the second heater 52 are connected to a power source.

[0084] Specifically, the crystal growth apparatus also includes a first thermocouple and a second thermocouple fixedly mounted on the insulation structure. The first thermocouple monitors the temperature inside the first temperature chamber 3, and the second thermocouple monitors the temperature inside the second temperature chamber 4. This facilitates the adjustment of the first heater 51 and the second heater 52, facilitates the determination of whether the raw material has been completely heated into a molten material, and facilitates the determination of the crystal growth status. Specifically, the first thermocouple is fixedly mounted on the upper insulation chamber 11, and the second thermocouple is fixedly mounted on the lower insulation chamber 13.

[0085] More specifically, the number of first temperature-measuring thermocouples is at least two, and the at least two first temperature-measuring thermocouples are distributed at intervals along the vertical direction to improve the temperature monitoring effect within the first temperature cavity 3.

[0086] More specifically, the number of second temperature-measuring thermocouples is at least two, and the at least two second temperature-measuring thermocouples are distributed at intervals along the vertical direction to improve the temperature monitoring effect within the second temperature cavity 4.

[0087] Specifically, crucible 7 is a quartz crucible; or, crucible 7 is a quartz crucible coated with a carbon film; or, crucible 7 is a quartz crucible containing a platinum crucible, etc. The type of crucible 7 is selected according to the crystal growth requirements.

[0088] The present invention also provides a crucible processing method, a raw material processing method, and a crystal growth control method executed sequentially. The crystal growth control method is used in the aforementioned crystal growth apparatus. By employing this crystal growth control method to control crystal growth, the effect of maintaining the crystal growth interface at a flat or slightly convex interface can be effectively improved, and the impurity removal capability during the crystal growth process can be effectively enhanced, thereby effectively improving the quality and performance of the prepared crystal.

[0089] Taking crucible 7 as an example, which uses a quartz crucible, the crucible treatment method includes:

[0090] The crucible 7 of a preset size is immersed in HF solution for a first preset time; after ultrasonic cleaning with deionized water, the crucible 7 is dried in a vacuum oven for a second preset time; the crucible 7 is then placed in a tube furnace for carbon plating; and after carbon plating, it is cooled for a third preset time. Specifically, the steps for placing the crucible 7 in the tube furnace for carbon plating include: using high-purity nitrogen as the carrier gas, with a preset inlet flow rate and a preset inlet temperature, and using methane as the carbon source, the crucible 7 is placed in the tube furnace for a fourth preset time for carbon plating.

[0091] This setup ensures the quality of the processed crucible 7, and the coating layer of crucible 7 effectively prevents the raw materials from reacting with the quartz crucible and introducing additional impurities.

[0092] Understandably, the values ​​for the preset size specifications, first preset time, second preset time, third preset time, preset airflow rate, third preset temperature, and fourth preset time will differ for different types of crystal raw materials and the desired crystal blank size. These preset size specifications, first preset time, second preset time, third preset time, preset airflow rate, third preset temperature, and fourth preset time are all empirical values ​​obtained from extensive prior testing.

[0093] The specific structure of the tubular furnace is existing technology, so it will not be described in detail here.

[0094] Taking crucible 7 as an example, which uses a quartz crucible, the raw material processing method includes:

[0095] The raw material is loaded into the coated crucible 7; the raw material is then dried using a vacuum drying device to remove OH- ions; after drying, the crucible 7 is welded shut. Specifically, the steps for drying the raw material to remove OH- ions and then vacuum drying include: controlling the vacuum degree to be greater than or equal to 1.0 × 10⁻⁶ at room temperature. -4 Pa, the raw material is kept at a constant temperature for the fifth preset time; after the fifth preset time, the temperature is increased to the fourth preset temperature at the third preset rate, while maintaining a vacuum degree greater than or equal to 1.0 × 10⁻⁶. -4Pa, the raw material is kept at a constant temperature for the sixth preset time; after the sixth preset time, the temperature is increased to the fifth preset temperature at the fourth preset rate, while maintaining a vacuum degree greater than or equal to 1.0 × 10⁻⁶. -4 Pa, the seventh set time for keeping the raw material warm; control the cooling to room temperature at the fifth preset rate to complete the drying.

[0096] Specifically, the room temperature, the fourth preset temperature, and the fifth preset temperature increase sequentially to ensure the quality of the dried materials.

[0097] Understandably, the values ​​of the fifth preset duration, third preset rate, fourth preset temperature, sixth preset duration, fourth preset rate, fifth preset temperature, seventh preset duration, and fifth preset rate will differ for different types of crystal raw materials and the desired crystal blank size. The fifth preset duration, third preset rate, fourth preset temperature, sixth preset duration, fourth preset rate, fifth preset temperature, seventh preset duration, and fifth preset rate are all empirical values ​​obtained from extensive prior experiments.

[0098] The specific structure of the vacuum drying device is existing technology, so it will not be described in detail here.

[0099] The methods for controlling crystal growth include:

[0100] S100, Melting Material: Place the sealed crucible 7 on the crystal seat 6; control the temperature of the first temperature chamber 3 to the sixth preset temperature, control the temperature of the second temperature chamber 4 to the seventh preset temperature, so that the temperature gradient at the heat insulation plate 2 is the preset temperature gradient; control the crystal seat 6 to move in the up and down direction so that the crucible 7 moves into the first temperature chamber 3, and keep it warm for the eighth preset time so that the raw material is completely transformed into molten material.

[0101] Specifically, the preset temperature gradient is calculated based on the sixth and seventh preset temperatures. The specific calculation method is existing technology and will not be described in detail here.

[0102] S200, Crystal growth: Control the crucible 7 to move from the first temperature chamber 3 to the second temperature chamber 4 at a first preset rate until the crucible 7 is completely located in the heat dissipation channel of the second heat exchanger 8; keep the first heat exchanger and the second heat exchanger 8 in heat exchange, or simultaneously control the first heat exchanger and the second heat exchanger 8 to start heat exchange.

[0103] It is understandable that the first heat exchanger and the second heat exchanger 8 can be configured according to actual operating conditions: when the sealed crucible 7 is placed on the crystal seat 6 to begin melting, the first heat exchanger and the second heat exchanger 8 should be controlled to start heat exchange synchronously. Alternatively, when the molten material in the crucible 7 begins to grow, i.e. when the crystal begins to grow, the first heat exchanger and the second heat exchanger 8 should be controlled to start heat exchange synchronously.

[0104] Preferably, when the sealed crucible 7 is placed on the crystal seat 6 to begin melting, the first heat exchanger and the second heat exchanger 8 are controlled to start heat exchange synchronously.

[0105] Specifically, when the sealed crucible 7 is placed on the crystal seat 6 to start melting, and the first heat exchanger and the second heat exchanger 8 start heat exchange synchronously: before the crystal begins to grow, the flow rate of the heat exchange medium in the first heat exchanger is less than or equal to the flow rate of the heat exchange medium in the first heat exchanger when the crystal begins to grow.

[0106] Before the crucible 7 enters the second temperature chamber 4 in a vertical direction, the flow rate of the first heat exchange medium flowing into the first heat exchange tube is less than or equal to the flow rate of the first heat exchange medium flowing into the first heat exchange tube when the crucible 7 begins to enter the second temperature chamber 4 in a vertical direction. Before the crucible 7 enters the second temperature chamber 4 in a vertical direction, the flow rate of the second heat exchange medium flowing into the second heat exchange tube is less than or equal to the flow rate of the second heat exchange medium flowing into the second heat exchange tube when the crucible 7 begins to enter the second temperature chamber 4 in a vertical direction.

[0107] S300. When the crucible 7 begins to enter the second temperature chamber 4 in the vertical direction, the heating power of the second heater 52 is controlled to decrease at a second preset rate, while the first heat exchanger and the second heat exchanger 8 continue to exchange heat, so that the temperature in the second temperature chamber 4 is adjusted to be within the preset temperature range until the crystal growth in the crucible 7 ends.

[0108] This crystal growth control method sets that during crystal growth, the first heat exchanger and the second heat exchanger 8 continue to exchange heat, or simultaneously control the first heat exchanger and the second heat exchanger 8 to begin exchanging heat. Furthermore, when the crucible 7 begins to enter the second temperature chamber 4 in the vertical direction, the heating power of the second heater 52 is controlled to decrease at a second preset rate, while simultaneously maintaining the first heat exchanger and the second heat exchanger 8 in continuous heat exchange. This allows the heat from the center and periphery of the crystal to be dissipated through the coordinated action of the first heat exchanger and the second heat exchanger 8 while gradually reducing the temperature of the second temperature chamber 4. This improves the efficiency and effectiveness of dissipating latent heat and melt overheat, effectively enhancing the uniformity of heat dissipation in the crystal. Compared to related technologies, this method effectively improves the ability to maintain the crystal growth interface at a flat or slightly convex interface, effectively improving the impurity removal capability during crystal growth, thereby improving the quality and performance of the prepared crystal.

[0109] Optionally, in this embodiment, the thermal conductivity of the first heat exchange medium is less than that of the second heat exchange medium. This configuration ensures that the heat dissipation capacity of the two second heat exchange components 8 matches the heat dissipation capacity of the crystal, resulting in a relatively gentle cooling temperature change and preventing crystal cracking caused by excessive cooling rates. This further improves the quality and performance of the prepared crystal.

[0110] Optionally, in this embodiment, when the crucible 7 begins to enter the second temperature chamber 4 in the vertical direction, the flow rate of the first heat exchange medium is gradually increased to a first preset flow rate, and the flow rate of the second heat exchange medium is simultaneously gradually increased to a second preset flow rate. This adjusts the temperature within the second temperature chamber 4 to within a preset temperature range until the crystal growth within the crucible 7 is complete. When the crucible 7 begins to enter the second temperature chamber 4 in the vertical direction, the heat dissipation capacity of the two second heat exchange components 8 is further matched with the heat dissipation capacity of the crystal, thereby further avoiding crystal cracking caused by excessive cooling rates and further improving the quality and performance of the prepared crystal.

[0111] Specifically, when the crucible 7 begins to enter the second temperature chamber 4 in the vertical direction, the heating power of the first heater 51 can be finely adjusted to further enhance the effect of maintaining the crystal growth interface at a flat or slightly convex interface.

[0112] When the crystal raw material is CsI:

[0113] Specifically, the range of the sixth preset temperature is 650℃~850℃.

[0114] Specifically, the range of the seventh preset temperature is 200~450℃.

[0115] Specifically, the value of the eighth set duration is greater than or equal to 10 hours. It can be understood that when the value of the eighth set duration is greater than or equal to 10 hours, it can be guaranteed that the raw materials are completely transformed into molten material.

[0116] Specifically, the range of the first preset rate is 0.6 mm / h to 4 mm / h.

[0117] Specifically, the second preset rate is 10W / mm.

[0118] Specifically, the preset temperature range is 330℃~350℃.

[0119] Specifically, the first heat exchange medium is argon gas, the inlet temperature of the first heat exchange medium is 30°C, and the initial inlet flow rate of the first heat exchange medium is less than or equal to 10 L / min.

[0120] Specifically, the first preset flow rate ranges from 20 L / min to 100 L / min. In this embodiment, the first preset flow rate is set to 40 L / min. It is understood that the value of the first preset flow rate can be adjusted according to actual working conditions.

[0121] Specifically, the second heat exchange medium is water, the inlet temperature of the second heat exchange medium is 30°C, and the initial inlet water flow rate of the second heat exchange medium is less than or equal to 5L / min.

[0122] Specifically, the second preset flow rate ranges from 6 L / min to 30 L / min. In this embodiment, the second preset flow rate is set to 40 L / min. It is understood that the value of the second preset flow rate can also be adjusted according to actual working conditions.

[0123] Specifically, when the first heat exchanger starts to exchange heat, water is introduced into the third heat exchange tube, and the water flow rate in the third heat exchange tube is controlled to be 15L / min, and the water temperature in the third heat exchange tube is controlled to be 30℃.

[0124] Specifically, the value ranges for the sixth preset temperature, the seventh preset temperature, the first preset rate, the preset temperature, the first preset flow rate, the second preset flow rate, the initial air inlet flow rate of the first heat exchange medium, and the initial water inlet flow rate of the second heat exchange medium are all empirical ranges obtained from extensive previous experiments. The eighth setting time, the second preset rate, the air inlet temperature of the first heat exchange medium, the air inlet temperature of the second heat exchange medium, the water inlet flow rate in the third heat exchange tube, and the water inlet temperature in the third heat exchange tube are all empirical values ​​obtained from extensive previous experiments.

[0125] In this embodiment, the specific process for preparing a CsI crystal with a blank size of Φ100mm×430mm is as follows:

[0126] A crucible 7 with a diameter of 105 mm and a diameter of 650 mm was immersed in HF solution for 5 hours. After ultrasonic cleaning with deionized water, the crucible 7 was dried in a vacuum oven for 7 hours. Using high-purity nitrogen as the carrier gas at an inlet flow rate of 5.5 L / h and an inlet temperature of 1015 °C, and methane as the carbon source, the crucible 7 was placed in a tube furnace for carburizing for 5 hours. After carburizing, it was cooled for 15 hours to ensure the quality of the obtained crucible 7.

[0127] A CsI raw material with a purity of 99.999% was loaded into the coated crucible 7. At room temperature, the vacuum level was controlled to be greater than or equal to 1.0 × 10⁻⁶. -4Pa, hold the CsI raw material at this temperature for 2 hours; after holding for 2 hours, raise the temperature to 150℃ at a rate of 30℃ / h, while maintaining a vacuum degree greater than or equal to 1.0×10⁻⁶. -4 Pa, hold the CsI raw material at this temperature for 2 hours; after holding for 2 hours, raise the temperature to 250℃ at a rate of 30℃ / h, while maintaining a vacuum degree greater than or equal to 1.0×10⁻⁶. -4 Pa was applied to the CsI raw material and kept at that temperature for 2 hours. After 2 hours, the temperature was increased to room temperature at a rate of 30℃ / h to complete the drying process. After drying, crucible 7 was welded shut to ensure the quality of the dried material.

[0128] The sealed crucible 7 is placed on the crystal seat 61, and the crucible 7 is moved vertically into the first temperature chamber 3. The temperature of the first temperature chamber 3 is controlled at 740℃, and the temperature of the second temperature chamber 4 is controlled at 340℃, so that the temperature gradient at the heat insulation plate 2 is 28.5℃ / cm. The raw material is kept at this temperature for 12 hours, so that the raw material is completely transformed into a molten state. During this period, the first heat exchanger and the second heat exchanger 8 are controlled to start heat exchange simultaneously. Specifically, when the first heat exchanger starts heat exchange, water is introduced into the third heat exchange tube, and the water flow rate in the third heat exchange tube is controlled at 15L / min, and the water temperature in the third heat exchange tube is controlled at 30℃. Specifically, when the second heat exchanger 8 starts heat exchange, argon gas is introduced into the first heat exchange tube, and the argon gas inlet temperature is 30℃, and the initial argon gas inlet flow rate is 10L / min. When the second heat exchanger 8 starts heat exchange, water is introduced into the second heat exchanger tube. The water inlet temperature is 30℃ and the initial water inlet flow rate is 5L / min.

[0129] When the molten material in the crucible 7 begins to grow, the crucible 7 is controlled to move from the first temperature chamber 3 to the second temperature chamber 4 at a rate of 0.7 mm / h until the crucible 7 is completely located in the heat dissipation channel of the second heat exchanger 8; when the molten material in the crucible 7 begins to grow, the first heat exchanger and the second heat exchanger 8 are kept in constant heat exchange.

[0130] As the crucible 7 begins to descend vertically, the heating power of the second heater 52 is controlled to decrease at a rate of 10 W / mm. During the descent of the crucible 7, the first heat exchanger and the second heat exchanger 8 continue to exchange heat synchronously, so that the temperature in the second temperature chamber 4 is adjusted to a preset temperature range of 340℃±10℃ until the crystal growth in the crucible 7 is completed. Specifically, at this time, the argon gas inlet temperature is maintained at 30℃, and the argon gas inlet flow rate is controlled to gradually increase from 10L / min to 40L / min; the water inlet temperature is maintained at 30℃, and the water inlet flow rate is controlled to gradually increase from 5L / min to 10L / min, so that the temperature in the second temperature chamber 4 is adjusted to a preset temperature range of 340℃±10℃ until the crystal growth in the crucible 7 is completed.

[0131] After the CsI crystal growth is complete, the temperature is lowered to room temperature at a rate of 10°C / h. The crucible 7 is then removed, and the CsI crystal is taken out of the crucible 7 to obtain a CsI crystal blank with dimensions of Φ100mm×430mm.

[0132] like Figure 4 As shown, the CsI crystals prepared using the crystal growth control method and crystal growth apparatus of this embodiment are clear and transparent, with no obvious black inclusions, which effectively improves the quality and performance of the prepared CsI crystals.

[0133] Combination Figure 4 and Figure 5 As shown, compared with the CsI crystal prepared by setting only the first heat exchanger, the CsI crystal has a poor impurity removal effect and poor quality in the later stage of growth due to the gradual increase of temperature in the second temperature cavity 4.

[0134] In another embodiment, the specific process for preparing a CsI crystal with a blank size of Φ105mm×650mm is as follows:

[0135] A crucible 7 with a diameter of 105 mm and a diameter of 650 mm was immersed in HF solution for 5 hours. After ultrasonic cleaning with deionized water, the crucible 7 was dried in a vacuum oven for 7 hours. Using high-purity nitrogen as the carrier gas at an inlet flow rate of 5.5 L / h and an inlet temperature of 1015 °C, and methane as the carbon source, the crucible 7 was placed in a tube furnace for carburizing for 5 hours. After carburizing, it was cooled for 15 hours to ensure the quality of the obtained crucible 7.

[0136] A CsI raw material with a purity of 99.999% was loaded into the coated crucible 7. At room temperature, the vacuum level was controlled to be greater than or equal to 1.0 × 10⁻⁶. -4 Pa, hold the CsI raw material at this temperature for 2 hours; after holding for 2 hours, raise the temperature to 150℃ at a rate of 30℃ / h, while maintaining a vacuum degree greater than or equal to 1.0×10⁻⁶. -4 Pa, hold the CsI raw material at this temperature for 2 hours; after holding for 2 hours, raise the temperature to 250℃ at a rate of 30℃ / h, while maintaining a vacuum degree greater than or equal to 1.0×10⁻⁶. -4 Pa was applied to the CsI raw material and kept at that temperature for 2 hours. After 2 hours, the temperature was increased to room temperature at a rate of 50℃ / h to complete the drying process. After drying, crucible 7 was welded shut to ensure the quality of the dried material.

[0137] The sealed crucible 7 is placed on top of the first heat exchanger, and the crucible 7 is moved vertically into the first temperature chamber 3. The temperature of the first temperature chamber 3 is controlled at 720℃, and the temperature of the second temperature chamber 4 is controlled at 300℃, so that the temperature gradient at the heat insulation plate 2 is 30℃ / cm. The raw material is kept at this temperature for 12 hours to completely transform it into molten material. During this period, the first and second heat exchangers 8 are controlled to start heat exchange simultaneously. Specifically, when the first heat exchanger starts heat exchange, water is introduced into the third heat exchange tube, and the water flow rate in the third heat exchange tube is controlled at 15L / min, and the water temperature in the third heat exchange tube is controlled at 30℃. Specifically, when the second heat exchanger 8 starts heat exchange, argon gas is introduced into the first heat exchange tube, and the argon gas inlet temperature is 30℃, and the initial argon gas inlet flow rate is 10L / min. When the second heat exchanger 8 starts heat exchange, water is introduced into the second heat exchanger tube. The water inlet temperature is 30℃ and the initial water inlet flow rate is 5L / min.

[0138] When the molten material in the crucible 7 begins to grow, the first heat exchanger is controlled to move from the first temperature chamber 3 to the second temperature chamber 4 at a rate of 1 mm / h until the crucible 7 is completely located in the heat dissipation channel of the second heat exchanger 8; when the molten material in the crucible 7 begins to grow, the first heat exchanger and the second heat exchanger 8 are kept in constant heat exchange.

[0139] As the crucible 7 descends vertically, the heating power of the second heater 52 decreases at a rate of 10 W / mm. As the crucible 7 begins to enter the second temperature chamber 4 vertically, the first and second heat exchangers 8 simultaneously continue heat exchange, adjusting the temperature within the second temperature chamber 4 to a preset temperature range of 300℃ ± 10℃ until the crystal growth within the crucible 7 is complete. Specifically, the argon gas inlet temperature is maintained at 30℃, and the argon gas inlet flow rate is gradually increased from 10 L / min to 40 L / min; the water inlet temperature is maintained at 30℃, and the water inlet flow rate is gradually increased from 5 L / min to 15 L / min, thus adjusting the temperature within the second temperature chamber 4 to a preset temperature range of 300℃ ± 10℃ until the crystal growth within the crucible 7 is complete.

[0140] After the CsI crystal growth is complete, the temperature is lowered to room temperature at a rate of 10°C / h. The crucible 7 is then removed, and the CsI crystal is taken out of the crucible 7 to obtain a CsI crystal blank with dimensions of Φ100mm×450mm.

[0141] Figure 6 To illustrate the preparation of CsI using the crystal growth control method and crystal growth apparatus of this embodiment, and the preparation of CsI using a crystal growth apparatus with only a first heat exchanger, a line graph comparing the crystal growth length with the temperature of the second temperature cavity 4 is provided. Figure 6 It can be clearly seen that when CsI is prepared using the crystal growth control method and crystal growth apparatus of this embodiment, the temperature in the second temperature chamber 4 can be effectively maintained within a preset temperature range of 300℃±10℃, thereby effectively improving the quality and performance of the prepared CsI crystal.

[0142] In another embodiment, the specific process for preparing an AgGaS2 crystal with a blank size of Φ45mm×180mm is as follows:

[0143] A Φ45mm×450mm crucible 7 was immersed in HF solution for 5 hours. After ultrasonically cleaning with deionized water, crucible 7 was dried in a vacuum oven for 7 hours. Using high-purity nitrogen as the carrier gas at an inlet flow rate of 3L / h and an inlet temperature of 1015℃, and methane as the carbon source, crucible 7 was placed in a tube furnace for carburizing for 5 hours. After carburizing, it was cooled for 15 hours to ensure the quality of the obtained crucible 7.

[0144] Ag with a purity of 99.999%, Ga with a purity of 99.999%, and S with a purity of 99.999% were used as raw materials. In a vacuum drying apparatus filled with argon gas, the three raw materials were weighed in a stoichiometric ratio of 1:1:2 and then placed into a coated crucible 7. A vacuum was then evacuated from the crucible 7 to achieve a vacuum degree of 1.0 × 10⁻⁶. -4 The pressure is increased to above 1050°C, and then the crucible 7 is welded shut. The welded crucible 7 is placed in a horizontal high-pressure furnace, the temperature is set to 1050°C, and the reaction time is 24 hours to synthesize AgGaS2 raw material. The specific structure of the horizontal high-pressure furnace is existing technology and will not be described in detail here.

[0145] The synthesized AgGaS2 raw material was crushed and placed into another coated crucible 7, and then subjected to a vacuum degree greater than or equal to 1.0 × 10⁻⁶. -4 The crucible 7 containing AgGaS2 was welded and sealed under Pa conditions.

[0146] A crucible 7 containing AgGaS2 is placed on the crystal base 61, and the crucible 7 is moved vertically into the first temperature chamber 3. The temperature of the first temperature chamber 3 is controlled at 1050℃, and the temperature of the second temperature chamber 4 is controlled at 940℃, so that the temperature gradient at the heat insulation plate 2 is 35℃ / cm. The raw material is kept at this temperature for 12 hours to completely transform it into molten material. During this period, the first heat exchanger and the second heat exchanger 8 are controlled to start heat exchange simultaneously. Specifically, when the first heat exchanger starts heat exchange, water is introduced into the third heat exchange tube, and the water flow rate in the third heat exchange tube is controlled at 10L / min, and the water temperature in the third heat exchange tube is controlled at 30℃. Specifically, when the second heat exchanger 8 starts heat exchange, argon gas is introduced into the first heat exchange tube, and the argon gas inlet temperature is 30℃, and the initial argon gas inlet flow rate is 10L / min. When the second heat exchanger 8 starts heat exchange, water is introduced into the second heat exchanger tube. The water inlet temperature is 30℃ and the initial water inlet flow rate is 5L / min.

[0147] When the molten material in the crucible 7 begins to grow, the first heat exchanger is controlled to move from the first temperature chamber 3 to the second temperature chamber 4 at a rate of 0.5 mm / h until the crucible 7 is completely located in the heat dissipation channel of the second heat exchanger 8; when the molten material in the crucible 7 begins to grow, the first heat exchanger and the second heat exchanger 8 are kept in constant heat exchange.

[0148] As the crucible 7 begins to enter the second temperature chamber 4 in a vertical direction, the heating power of the second heater 52 is controlled to decrease at a rate of 10 W / mm. Simultaneously, as the crucible 7 enters the second temperature chamber 4, the first and second heat exchangers 8 continue to exchange heat, thereby adjusting the temperature within the second temperature chamber 4 to a preset temperature range of 940℃ ± 10℃ until the crystal growth within the crucible 7 is complete. Specifically, the argon gas inlet temperature is maintained at 30℃, and the argon gas inlet flow rate is gradually increased from 10 L / min to 75 L / min; the water inlet temperature is maintained at 30℃, and the water inlet flow rate is gradually increased from 5 L / min to 25 L / min, thereby adjusting the temperature within the second temperature chamber 4 to a preset temperature range of 940℃ ± 10℃ until the crystal growth within the crucible 7 is complete.

[0149] After the AgGaS2 crystal growth is complete, the temperature is lowered to room temperature at a rate of 10°C / h. The crucible 7 is then removed, and the AgGaS2 crystal is taken out of the crucible 7 to obtain an AgGaS2 crystal blank with dimensions of Φ45mm×180mm.

[0150] like Figure 7As shown, the AgGaS2 crystals prepared using the crystal growth control method and crystal growth apparatus of this embodiment have no obvious black inclusions, which effectively improves the quality and performance of the prepared AgGaS2 crystals.

[0151] Combination Figure 7 and Figure 8 As shown, compared with the AgGaS2 crystal prepared by only setting the first heat exchanger, the AgGaS2 crystal has a poor impurity removal effect in the middle and late stages of growth due to the gradual increase in temperature in the second temperature cavity 4. This causes the crystallization interface to move upward and the crystal growth interface to shift from the temperature gradient region. As a result, the AgGaS2 crystal has a poor quality.

[0152] Therefore, the crystal growth control method and crystal growth device can effectively improve the effect of maintaining the crystal growth interface at a flat or slightly convex interface, effectively improve the crystal growth driving force, and effectively improve the impurity removal ability during the crystal growth process, thereby effectively improving the quality and performance of the prepared crystal.

[0153] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art should understand that the scope of disclosure involved in the present invention is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalent features without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A method for controlling crystal growth, characterized in that, The crystal growth apparatus includes a heat preservation structure, a heating component, a crystal seat (6), a crucible (7), and a heat exchange component; the heat preservation structure forms a first temperature cavity (3) and a second temperature cavity (4) that are distributed and connected from top to bottom; the heating component includes a first heater (51) fixedly disposed in the first temperature cavity (3) and a second heater (52) fixedly disposed in the second temperature cavity (4); the heat exchange component includes a first heat exchange element fixedly disposed in the crystal seat (6) and a second heat exchange element (8) fixedly disposed in the second temperature cavity (4), the crystal seat (6) is configured to move downward from the first temperature cavity (3) to the second temperature cavity (4), the crystal seat (6) and / or the first heat exchange element are used to support the crucible (7), and the first heat exchange element is also used to dissipate heat from the raw material in the crucible (7); the second heat exchange element (8) is provided with a heat dissipation channel that runs through the vertical direction, the heat dissipation channel is used to accommodate the crystal seat (6), the first heat exchange element and the crucible (7); the crystal growth control method includes: When the molten material in the crucible (7) begins to grow, the crucible (7) is controlled to move from the first temperature chamber (3) to the second temperature chamber (4) at a first preset rate until the crucible (7) is completely located in the heat dissipation channel of the second heat exchanger (8); when the molten material in the crucible (7) begins to grow, the first heat exchanger and the second heat exchanger (8) are kept in heat exchange simultaneously, or the first heat exchanger and the second heat exchanger (8) are controlled to start heat exchange simultaneously. When the crucible (7) begins to enter the second temperature cavity (4) along the up-down direction, the heating power of the second heater (52) is controlled to decrease at a second preset rate, and the first heat exchanger and the second heat exchanger (8) continue to exchange heat simultaneously, so that the temperature in the second temperature cavity (4) is adjusted to be within the preset temperature range until the crystal growth in the crucible (7) ends.

2. The crystal growth control method according to claim 1, characterized in that, The number of the second heat exchanger (8) is two, and both of the second heat exchangers (8) are heat exchange tubes. The heat exchange tube located above is the first heat exchange tube, and the heat exchange tube located below is the second heat exchange tube. When controlling the second heat exchanger (8) to perform heat exchange, a first heat exchange medium is introduced into the first heat exchange tube, and a second heat exchange medium is introduced into the second heat exchange tube simultaneously; the thermal conductivity of the first heat exchange medium is less than that of the second heat exchange medium. When the crucible (7) begins to enter the second temperature cavity (4) along the up-down direction, the flow rate of the first heat exchange medium is gradually increased to the first preset flow rate, and the flow rate of the second heat exchange medium is simultaneously increased to the second preset flow rate, so that the temperature in the second temperature cavity (4) is adjusted to be within the preset temperature range until the crystal growth in the crucible (7) ends.

3. The crystal growth control method according to claim 2, characterized in that, The molten material in the crucible (7) is CsI molten material; the first heat exchange medium is argon gas, the inlet temperature of the first heat exchange medium is 30°C, and the initial inlet flow rate of the first heat exchange medium is less than or equal to 10L / min.

4. The crystal growth control method according to claim 3, characterized in that, The first preset flow rate ranges from 20L / min to 100L / min.

5. The crystal growth control method according to claim 4, characterized in that, The first preset flow rate is 40 L / min.

6. The crystal growth control method according to claim 2, characterized in that, The molten material in the crucible (7) is CsI molten material; the second heat exchange medium is water, the inlet temperature of the second heat exchange medium is 30°C, and the initial inlet flow rate of the second heat exchange medium is less than or equal to 5L / min.

7. The crystal growth control method according to claim 6, characterized in that, The second preset flow rate ranges from 6L / min to 30L / min.

8. The crystal growth control method according to claim 7, characterized in that, The second preset flow rate is 40 L / min.

9. The crystal growth control method according to any one of claims 1-8, characterized in that, The first heat exchange component is a third heat exchange tube; the molten material in the crucible (7) is CsI molten material; When the first heat exchanger starts to exchange heat, water is introduced into the third heat exchange tube, and the water flow rate in the third heat exchange tube is controlled to be 15L / min, and the water temperature in the third heat exchange tube is controlled to be 30℃.

10. The crystal growth control method according to any one of claims 1-8, characterized in that: The molten material in the crucible (7) is CsI molten material; The first preset rate ranges from 0.6 mm / h to 4 mm / h. The second preset rate is 10W / mm; The preset temperature range is 330℃~350℃.

Images