A crucible-free wall-contact single crystal growth method based on a necked crucible

Abstract

The invention discloses a necking crucible-based crucible wall-free contact-type single crystal growth method which is applicable to the large-diameter high-quality single crystal growth of materials with crystal density larger than melt density. According to the method, a crucible with necking in the middle is designed by utilizing the physical property that the volume of a tellurium-zinc-cadmium (CdZnTe) melt is decreased when the tellurium-zinc-cadmium (CdZnTe) melt is solidified; a crystal grows in the crucible from the top to the bottom; when the melt is solidified to the necking part of the crucible, the crystal is fixed by the necking and do not glide; as the volume is decreased, the diameter of the crystal below the necking part of the crucible is less than the inner diameter of the crucible; the crystal is separated from the crucible wall; and the larger the diameter of the crystal is, the larger the gap between the crystal and the crucible wall is and the more obvious the separation is. The method has the advantages that the growth diameter of the crystal is large and the quality is good.

Description

technical field [0001] The present invention relates to a non-crucible wall contact single crystal growth method, in particular to a crucible wall-free contact single crystal growth method based on a constricted crucible, which is suitable for large diameter high Quality single crystal growth, especially for CdZnTe single crystal growth. Background technique [0002] Mercury cadmium telluride (HgCdTe, MCT) infrared focal plane detector has important applications in high-end infrared detection fields such as military infrared imaging and space remote sensing. The composition is x=4% cadmium zinc telluride (Cd 1-x Zn x Te or CdZnTe) single crystal material is the best substrate material for the preparation of high-performance long-wave and very long-wave mercury cadmium telluride infrared focal plane detectors. Therefore, major developed countries in the world have invested a lot of energy in the preparation of CdZnTe single crystals. The main research goals are to increase ...

AI Technical Summary

Problems solved by technology

[0005] 1 Due to the low thermal conductivity of CdZnTe materials, it is difficult to control the solid-liquid interface when growing large-diameter crystals

Therefore, it is difficult to increase the single crystal diameter

[0006] 2. During the crystallization process in the crucible, the parasitic nucleation of the crucible wall is easy to occur

[0007] 3. During the crystallization process in the crucible, the crystal defect density is high due to the compressive stress of the crucible on the crystal.

[0008] 4 Due to the low stacking fault energy of CdZnTe materials, the existence of stress easily leads to twinning

[0009] 5. Because the convection of the melt is difficult to control, the uniformity of the grown crystals is often not as good as that of the crystals grown by the pulling method

[0010] To sum up, temperature field control and crucible contact are one of the main reasons why it is difficult to increase the diameter of CdZnTe single crystal and improve the quality of single crystal

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