阅读说明：本技术 一种制备碲化镉或碲锌镉多晶料的方法 (Method for preparing cadmium telluride or cadmium zinc telluride polycrystal material ) 是由 孙士文 于 2020-09-08 设计创作，主要内容包括：本发明涉及一种碲化镉或碲锌镉多晶料的制备方法,其特征在于包括以下制备工艺流程：1)将第一坩埚、盖合第一坩埚的第一盖子清洗干净并烘干,其中,第一坩埚具有沿外周壁的环形槽；第一盖子的顶部封闭、底部开口且侧壁能够插入环形槽内；2)按拟合成碲化镉的配比称取单质碲、单质镉；或者按拟合成碲锌镉的配比称取单质碲、单质镉、单质锌。本发明的制备方法采用液封技术阻止镉蒸气挥发损失,第一坩埚可以重复多次使用,从而降低了成本；通过采用水平式坩埚增大碲单质与镉熔体的接触面积,使化合反应热量快速散失,避免积温,减轻了碲与镉化合反应的剧烈程度,降低了对合成设备的耐压要求,降低了设备成本。(The invention relates to a preparation method of cadmium telluride or cadmium zinc telluride polycrystal material, which is characterized by comprising the following preparation process flows: 1) cleaning and drying a first crucible and a first cover covering the first crucible, wherein the first crucible is provided with an annular groove along the outer peripheral wall; the top of the first cover is closed, the bottom of the first cover is opened, and the side wall of the first cover can be inserted into the annular groove; 2) weighing simple substance tellurium and simple substance cadmium according to the ratio of cadmium telluride; or weighing the simple substance tellurium, the simple substance cadmium and the simple substance zinc according to the mixture ratio of the tellurium, the zinc and the cadmium. The preparation method of the invention adopts the liquid seal technology to prevent the volatilization loss of the cadmium vapor, and the first crucible can be repeatedly used, thereby reducing the cost; the contact area of the tellurium simple substance and the cadmium melt is increased by adopting the horizontal crucible, so that the heat of the chemical combination reaction is quickly dissipated, the accumulated temperature is avoided, the intensity of the chemical combination reaction of tellurium and cadmium is reduced, the pressure-resistant requirement on the synthesis equipment is lowered, and the equipment cost is lowered.)

1. A method for preparing cadmium telluride or cadmium zinc telluride polycrystal materials is characterized by comprising the following preparation process flows:

1) cleaning and drying the first crucible and a first cover covering the first crucible; wherein the first crucible has an annular groove along the outer peripheral wall; the top of the first cover is closed, the bottom of the first cover is opened, and the side wall of the first cover can be inserted into the annular groove;

2) weighing simple substance tellurium and simple substance cadmium according to the ratio of cadmium telluride; or weighing simple substance tellurium, simple substance cadmium and simple substance zinc according to the ratio of tellurium, zinc and cadmium;

3) putting the weighed materials into a first crucible;

4) inserting the side wall of the first cover into the annular groove, covering the first crucible, and putting a liquid sealant into the annular groove;

5) placing the first crucible into a second crucible in a synthesis furnace; wherein the synthesis furnace has multiple temperature zones;

6) vacuumizing the interior of the synthesis furnace, and then filling inert gas with certain pressure;

7) operating a connecting rod arranged on the synthesis furnace to cover the second cover on the second crucible; wherein the second cover is in sealing fit with the second crucible;

8) firstly, heating the liquid sealant to melt the liquid sealant; then heating the first crucible to completely melt the cadmium simple substance; continuing heating to melt the elemental tellurium or the elemental tellurium and the elemental zinc in the first crucible; the molten tellurium and cadmium melt or cadmium zinc melt are subjected to chemical combination reaction to generate cadmium telluride or cadmium zinc telluride;

9) after all the elemental materials react to generate cadmium telluride or cadmium zinc telluride, heating the first crucible to enable the cadmium telluride or the cadmium zinc telluride to be in a molten state, preserving heat, and then slowly cooling to room temperature;

10) exhausting the inert gas in the synthesis furnace, operating the connecting rod to lift the second cover, and taking the first crucible out of the second crucible; and dissolving the liquid sealant in the annular groove, opening the first cover, and taking the cadmium telluride or cadmium zinc telluride crystal ingot out of the first crucible.

2. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: in the step 3), the elemental tellurium is firstly tiled at the bottom of the first crucible, and then the elemental cadmium or the elemental cadmium and the elemental zinc are tiled on the elemental tellurium.

3. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: and in the step 4), boron trioxide is used as a liquid sealant.

4. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: in the step 4), the height of the liquid after the liquid sealing agent is melted is 5-100 mm, and the height of the side wall of the annular groove is 1.2 times greater than that of the liquid sealing agent.

5. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: in the step 7), the second cover and the second crucible are in threaded fit to realize mechanical sealing; or the second cover realizes mechanical sealing with the second crucible through the outer conical surface.

6. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: after vacuumizing in the step 6), ensuring that the vacuum degree in the first crucible is less than 1 KPa; the used inert gas is nitrogen or argon with the purity of more than 5N, after vacuum pumping, the inert gas with the pressure of 0.08-0.12 MPa is filled, then vacuum pumping and inert gas filling are carried out for 2-10 times, and finally the pressure of the inert gas filling is 0.2-10 MPa.

7. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: in the step 8), the liquid sealing agent is heated to 450-700 ℃ to be melted firstly; then heating the first crucible to 321-350 ℃ to completely melt the cadmium simple substance; and continuously heating to 470-500 ℃ to melt the simple substance tellurium or the simple substance tellurium and the simple substance zinc in the first crucible.

8. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: and 8) forming a temperature gradient in the first crucible along the horizontal direction, wherein the temperature gradient is 0.5-15 ℃/cm, so that the simple substance tellurium or the simple substance tellurium and the simple substance zinc in the first crucible are gradually melted from one end to the other end.

9. The method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in claim 1 wherein: in the step 9), after all the elemental materials react to generate cadmium telluride or cadmium zinc telluride, the temperature of the first crucible is increased to 1092-1300 ℃, and the temperature is kept for 0.1-100 h.

10. A method of preparing a cadmium telluride or cadmium zinc telluride polycrystalline material as set forth in any one of claims 1 to 9 wherein: the first crucible and the first cover are made of quartz materials, and the second crucible and the second cover are made of graphite materials; and in the step 1), after the first crucible is cleaned and dried, putting the first crucible into a carbon plating furnace, and plating a layer of carbon film on the inner surface of the first crucible.

Technical Field

The invention belongs to the field of preparation of crystal materials, and particularly relates to a synthetic cadmium telluride (CdTe) or cadmium zinc telluride (Cd) _{1- x} Zn _x Te) polycrystalline material.

Background

The cadmium telluride and cadmium zinc telluride crystals are the first choice substrate materials for preparing the mercury cadmium telluride infrared focal plane detector, are ideal semiconductor materials for preparing the nuclear radiation detector, and have wide application in the aspects of preparing thin film solar cells, infrared windows, optical modulators and the like.

In the preparation process of cadmium telluride and cadmium zinc telluride materials, the successful synthesis of the cadmium telluride and cadmium zinc telluride polycrystalline materials by adopting the tellurium simple substance, the cadmium simple substance and the zinc simple substance is a key technology, a quartz crucible vacuum sintering sealing method is usually adopted, after the synthesis is finished, the quartz crucible needs to be broken to take out crystal ingots inside, one quartz crucible needs to be lost every time of synthesis, and the cost is high; on the other hand, the tellurium simple substance and the cadmium simple substance can have violent reaction when being combined, and when the single synthesis amount is slightly large, the problem of explosion of a quartz crucible container can often occur, so that the materials are oxidized and scrapped, and equipment is damaged, thereby causing great economic loss.

Aiming at the difficulty of the existing synthesis process of cadmium telluride and cadmium zinc telluride polycrystal materials, the invention provides a method for synthesizing the cadmium telluride and cadmium zinc telluride polycrystal materials in an industrialized large-scale and low-cost manner.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for preparing cadmium telluride or cadmium zinc telluride polycrystal material with low cost, which is suitable for large-scale industrial production.

The technical scheme adopted by the invention is as follows: a method for preparing cadmium telluride or cadmium zinc telluride polycrystal materials is characterized by comprising the following preparation process flows:

1) cleaning and drying the first crucible and a first cover covering the first crucible; wherein the first crucible has an annular groove along the outer peripheral wall; the top of the first cover is closed, the bottom of the first cover is opened, and the side wall of the first cover can be inserted into the annular groove;

2) weighing simple substance tellurium and simple substance cadmium according to the ratio of cadmium telluride; or weighing simple substance tellurium, simple substance cadmium and simple substance zinc according to the ratio of tellurium, zinc and cadmium;

3) putting the weighed materials into a first crucible;

4) inserting the side wall of the first cover into the annular groove, covering the first crucible, and putting a liquid sealant into the annular groove;

5) placing the first crucible into a second crucible in a synthesis furnace; wherein the synthesis furnace has multiple temperature zones;

6) vacuumizing the interior of the synthesis furnace, and then filling inert gas with certain pressure;

7) operating a connecting rod arranged on the synthesis furnace to cover the second cover on the second crucible; wherein the second cover is in sealing fit with the second crucible;

8) firstly, heating the liquid sealant to melt the liquid sealant; then heating the first crucible to completely melt the cadmium simple substance; continuing heating to melt the elemental tellurium or the elemental tellurium and the elemental zinc in the first crucible; the molten tellurium and cadmium melt or cadmium zinc melt are subjected to chemical combination reaction to generate cadmium telluride or cadmium zinc telluride;

9) after all the elemental materials react to generate cadmium telluride or cadmium zinc telluride, heating the first crucible to enable the cadmium telluride or the cadmium zinc telluride to be in a molten state, preserving heat, and then slowly cooling to room temperature;

10) exhausting the inert gas in the synthesis furnace, operating the connecting rod to lift the second cover, and taking the first crucible out of the second crucible; and dissolving the liquid sealant in the annular groove, opening the first cover, and taking the cadmium telluride or cadmium zinc telluride crystal ingot out of the first crucible.

Preferably, in the step 3), the elemental tellurium is firstly spread at the bottom of the first crucible, and then the elemental cadmium or the elemental cadmium and the elemental zinc are spread on the elemental tellurium.

Preferably, diboron trioxide is used as the liquid sealant in the step 4). At high temperature, the boron trioxide melts into a liquid with higher viscosity, which can prevent the cadmium vapor in the first crucible from leaking.

Preferably, in the step 4), the height of the liquid after the liquid sealing agent is melted is 5-100 mm, and the height of the side wall of the annular groove is more than 1.2 times of the height of the liquid sealing agent. The liquid height of the liquid sealant after melting is too low to effectively prevent the cadmium vapor from leaking; too high a liquid level may increase the pressure difference between the inside and outside of the crucible, creating a hazard. Therefore, the height of the liquid after the liquid sealant is melted is controlled to be 5-100 mm.

Preferably, in the step 7), the second cover and the second crucible are mechanically sealed through threaded fit; or the second cover realizes mechanical sealing with the second crucible through the outer conical surface.

Preferably, the degree of vacuum in the first crucible after the vacuum pumping in the step 6) is less than 1 KPa; the used inert gas is nitrogen or argon with the purity of more than 5N, after vacuum pumping, the inert gas with the pressure of 0.08-0.12 MPa is filled, then vacuum pumping and inert gas filling are carried out for 2-10 times, and finally the pressure of the inert gas filling is 0.2-10 MPa. The pressure of the filled gas is too low, so that the loss of cadmium components caused by the volatilization of cadmium vapor can not be effectively prevented; the pressure of the filled gas is too high, the pressure resistance requirement on equipment is increased, and the equipment cost is higher. Therefore, the pressure of the inert gas is controlled to be 0.2-10 MPa.

Preferably, in the step 8), the liquid sealing agent is heated to 450-700 ℃ to be melted first; then heating the first crucible to 321-350 ℃ to completely melt the cadmium simple substance; and continuously heating to 470-500 ℃ to melt the simple substance tellurium or the simple substance tellurium and the simple substance zinc in the first crucible.

Preferably, in the step 8), a temperature gradient is formed in the first crucible along the horizontal direction, the temperature gradient is 0.5-15 ℃/cm, and the elemental tellurium or the elemental tellurium and the elemental zinc in the first crucible are gradually melted from one end to the other end. The tellurium melt reacts with the cadmium melt or the cadmium-zinc melt to generate cadmium telluride or cadmium-zinc telluride, heat can be generated in the chemical combination reaction process, and the heat can be used for heating unmelted tellurium simple substance or tellurium simple substance and zinc simple substance, so that energy is saved; and the first crucible keeps horizontal temperature gradient and continues to be heated, so that the tellurium simple substance or the tellurium simple substance and the zinc simple substance in the first crucible are gradually melted from one end of the crucible to the other end of the crucible.

Preferably, in the step 9), after all the elemental materials react to generate cadmium telluride or cadmium zinc telluride, the temperature of the first crucible is increased to 1092-1300 ℃, and the temperature is kept for 0.1-100 h.

Preferably, the first crucible and the first cover are made of quartz, and the second crucible and the second cover are made of graphite; and in the step 1), after the first crucible is cleaned and dried, putting the first crucible into a carbon plating furnace, and plating a layer of carbon film on the inner surface of the first crucible.

The invention has the advantages that: the liquid seal technology is adopted to prevent the volatilization loss of cadmium vapor, the first crucible does not need to be sintered and sealed, and the first crucible can be repeatedly used, so that the cost is reduced; the contact area of the tellurium simple substance and the cadmium melt is increased by adopting the horizontal crucible, so that the heat of the chemical combination reaction is quickly dissipated, the accumulated temperature is avoided, the intensity of the chemical combination reaction of tellurium and cadmium is reduced, the pressure-resistant requirement on the synthesis equipment is lowered, and the equipment cost is lowered. Therefore, the invention can meet the requirement of preparing cadmium telluride or cadmium zinc telluride polycrystal materials in an industrialized large scale at low cost.

Drawings

Fig. 1 is a schematic structural diagram of an embodiment of the present invention.

Wherein, 1 is a first crucible, 2 is a second crucible, 3 is a first cover, 4 is an annular groove, 5 is a second cover, 6 is a connecting rod, 7 is a horizontal pressure synthesis furnace with multiple temperature zones, 71 is a temperature zone I, 72 is a temperature zone II, 73 is a temperature zone III, 74 is a temperature zone IV, 75 is a temperature zone V, 8 is cooling water, and 9 is a heat insulation material.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.