CN103474501B - A kind of selective emitter gallium antimonide infrared cell and preparation method thereof - Google Patents

Abstract

The invention discloses a selective emitter gallium antimonide infrared battery and a preparation method thereof, comprising the steps of preparing a PN junction by a zinc diffusion method, preparing an electrode, surface passivation, and preparing an antireflection layer; the feature is that a zinc-gallium alloy is used as the Diffusion sources for sealed zinc diffusion form a zinc concentration profile with only a single diffusion front in an N-type gallium antimonide wafer. Adopting the method of the present invention can effectively contain the high-concentration diffusion layer on the surface of the gallium antimonide wafer after diffusion, and solve the problem that the precise corrosion is difficult to control after the traditional diffusion process; adopting the method of the present invention does not need to feed any The protective gas reduces the cost of the gallium antimonide battery; the selective emitter gallium antimonide infrared battery of the present invention prepared by the method of the present invention has a single diffusion front zinc curve inside it directly formed by diffusion without using a corrosion process, so Its electrical output performance is stable, and it can be used as an electric energy conversion element in an infrared photoelectric conversion system.

Description

A kind of selective emitter gallium antimonide infrared battery and its preparation method

technical field

The invention belongs to the technical field of infrared batteries, and in particular relates to a selective emitter gallium antimonide infrared battery and a preparation method thereof.

Background technique

Gallium antimonide has a band gap of 0.72eV, and infrared cells prepared by using gallium antimonide wafers can directly convert the near-infrared radiation energy generated by fuel combustion into electrical energy. When the combustion temperature is about 1200°C, the output power per unit area of the battery can reach 1.5-2W/cm ² . The infrared photoelectric conversion system using gallium antimonide battery as the power output element can be used as military individual power supply, military communication power supply, geological survey, forest range station, and field investigation power supply. It has the advantages of lightness and silence.

According to the introduction of US Patent US005091018A, the preparation process of gallium antimonide infrared battery usually includes the steps of wafer cleaning, preparation of surrounding diffusion barrier layer, zinc diffusion to prepare P-N junction, electrode deposition, preparation of anti-reflection film and other steps. Among them, the use of zinc diffusion method to prepare the P-N junction is the most critical, and the rest of the steps are common semiconductor processes. The zinc diffusion method used in the existing gallium antimonide infrared battery mainly adopts the open diffusion method of zinc-antimony alloy. This process will form a zinc concentration curve with two diffusion fronts inside the gallium antimonide wafer. In this type of diffusion curve, the first diffusion front area close to the wafer surface is deep and has a high zinc concentration. The higher zinc concentration can make a good ohmic contact between the upper surface electrode and the gallium antimonide wafer. However, in the battery In the light-receiving area, a higher zinc concentration will reduce the life of photogenerated carriers, reduce the quantum efficiency of the battery, and reduce the short-circuit current. Therefore, after the electrode is prepared, it is necessary to use an etching solution to accurately etch the first diffusion front area close to the wafer surface, so that the average spectral responsivity of the battery in the near-infrared band can reach about 70%. Moreover, this corrosion process is very difficult to control. This corrosion process is described in the US patents US005091018A and US005217539A on which the mass-produced gallium antimonide infrared battery technology is based: "The corrosion process of the emitter is time-consuming and not easy to automatically control. Each battery needs to be corroded, cleaned, tested, re-corroded, re-cleaned, re-corroded, and re-tested until the spectral responsivity of the battery rises to the specified value. This corrosion process needs to be repeated many times before the performance of the battery can be achieved. To meet the requirements, if there is too much corrosion at once, the open circuit voltage of the battery will drop sharply, and if the corrosion is too shallow, the optimal spectral responsivity of the battery will not be achieved.”

According to the introduction of US Patent US005217539A, in order to change the shortcoming that the corrosion process is difficult to control during the battery manufacturing process, JXC Corporation of the United States has developed a two-step diffusion method, that is, shallow diffusion is performed on the surface of the battery first, and then the light-receiving part of the battery surface is coated with photoresist Protect it, and expose the part that needs to be deposited for second deep diffusion. In this way, the electrode on the upper surface of the battery is deeply doped, which can form a good ohmic contact with the gallium antimonide wafer, and the light-receiving part of the battery surface is shallow. doping, the quantum efficiency is higher. Gallium antimonide cells prepared by this method have high efficiency, but even if shallow diffusion is used on the light-receiving part of the cell surface, since the diffusion method is still the open type of zinc-antimony alloy, there will still be a high-concentration diffusion layer on the wafer surface, which cannot Solve the problem fundamentally. Moreover, when using this process to prepare gallium antimonide batteries, a process of diffusion and photolithography will be added, thereby increasing the manufacturing cost of the batteries.

It can be seen that in the mass production of gallium antimonide infrared cells, the morphology of the zinc diffusion curve on the surface of gallium antimonide wafers has an important impact on the performance of the cells.

Contents of the invention

The purpose of the present invention is to propose a selective emitter gallium antimonide infrared battery and its preparation method to simplify the difficult-to-control corrosion process after the battery is prepared by the traditional single-step zinc diffusion method, and to stabilize the electrical output performance of each batch of batteries.

The preparation method of the selective emitter gallium antimonide infrared battery of the present invention includes cleaning the gallium antimonide wafer, preparing a silicon dioxide diffusion protection layer around the front of the wafer, preparing a PN junction by zinc diffusion, removing the back and peripheral P-type layers, Preparation of electrodes, surface passivation, preparation of anti-reflection layer; characterized in that: using zinc-gallium alloy as a diffusion source for sealed zinc diffusion to form a zinc concentration curve with only a single diffusion front in an N-type gallium antimonide wafer, specifically including Follow the steps below:

The first step is to put the N-type gallium antimonide wafer with tellurium Te concentration of 2-7×10 ¹⁷ cm ^-3 and <100> crystal orientation into xylene, acetone and ethanol successively for cleaning, and then use mass ratio Dilute hydrochloric acid with a concentration of 5-20% removes oxides on the surface of the wafer, and finally washes in deionized water and blows dry with nitrogen;

The second step is to deposit a layer of silicon dioxide with a thickness of 0.11 μm on the wafer by plasma chemical vapor deposition, and then use a photolithography process to define the diffusion area in the center of the wafer, and use the silicon dioxide layer in this central area with The corrosive solution is soaked and removed to obtain a gallium antimonide wafer that can be used for zinc diffusion, that is, a gallium antimonide wafer for diffusion preparation; the corrosive solution used to soak and remove silicon dioxide is a conventional formula, that is, according to 3ml of hydrofluoric acid: ammonium fluoride 6g: 10ml deionized water for proportioning;

The third step is to put the diffusion prepared GaSb wafer prepared in the second step and the diffusion source zinc-gallium alloy into the quartz tube in the diffusion furnace, vacuumize to 5-10Pa, and the flow rate is 1-3L/ Min of argon until the pressure in the quartz tube returns to an atmospheric pressure; then close the argon valve and continue vacuuming to 5-10Pa, close the valve connected to the vacuum pump to maintain the vacuum state in the quartz tube, and increase the temperature at a rate of 5-10°C/min to 450～500℃, keep a certain temperature point in the above temperature range for 1～3h, so that the zinc vapor diffuses into the wafer; when the high temperature process of maintaining this constant temperature point in the diffusion furnace is over, open the top cover of the diffusion furnace and use The built-in fan in the furnace quickly cools down to room temperature to end the diffusion process, and then takes out the diffused GaSb wafer, which is an N-type GaSb wafer with only a single diffusion front zinc curve inside;

The fourth step is to protect the front of the N-type gallium antimonide wafer with only a single diffusion front zinc curve obtained in the third step with a photoresist by using spin coating technology, and the immersion ratio is 3.5g of tartaric acid: 4mL of hydrogen peroxide: hydrogen fluoride Acid 1mL: 400mL of deionized water is used to remove the P-type layer on the periphery of the wafer and the back of the etching solution for 1 to 3 minutes, then soak in acetone solution to remove the photoresist; and then prepare it by magnetron sputtering method Electrodes for battery formation: first deposit Ti50nm/Pt50nm/Ag250nm on the back of the substrate in sequence as the back electrode, and heat to 280°C under a vacuum of 1 to 10×10 ^-4 Pa for 10 minutes; then The front side uses photolithography to define the area where electrodes need to be deposited, that is, the area where electrodes need to be prepared is exposed and the area where the photoelectric effect is generated is covered with photoresist, and then Pt50nm/Ag250nm is sequentially deposited on the front side of the substrate as the front electrode, and finally The thin film layer in the area where the photoelectric effect is generated on the front of the battery is removed by stripping-floating technology, and the upper and lower electrodes of the battery are prepared;

The fifth step is to soak the gallium antimonide battery with the upper and lower electrodes in the ammonium sulfide solution for 5-10 minutes to passivate the surface;

The sixth step is to deposit a layer of 0.15 μm silicon nitride layer on the front of the battery as an anti-reflection film by plasma chemical vapor deposition to obtain a selective emitter gallium antimonide infrared battery.

The preparation method of the zinc-gallium alloy diffusion source is as follows: zinc with a weight ratio of 3% and a purity of 99.9999% and gallium with a weight ratio of 97% and a purity of 99.9999% are placed in a quartz tube at the same time, and vacuumized to 5-10Pa and sealed, put it into a heating furnace and heat it to 600°C and keep it for 24 hours, so that the two elements can be fully mixed, and the zinc-gallium diffusion source required by the present invention can be obtained after cooling.

The selective emitter gallium antimonide infrared battery of the present invention prepared by the above method comprises: a gallium antimonide wafer having a PN junction formed on the surface zinc diffusion layer, the bottom of the wafer adopts Ti/Pt/Ag as the back electrode, The upper part of the wafer adopts Pt/Ag as the positive electrode, and a silicon dioxide anti-reflection layer is deposited on the positive electrode; the feature is that the zinc diffusion layer in the gallium antimonide infrared battery has a single diffusion front shape.

The principle adopted in the present invention is: since the self-diffusion rate of gallium atoms in gallium antimonide crystals is many times larger than that of antimony atoms, during the high-temperature diffusion process, if there is no gallium atom in the diffusion source, then gallium antimonide A large overflow of gallium atoms in the wafer will occur. In this case, zinc atoms can diffuse by occupying gallium vacancies in the gallium antimonide wafer until the concentration of zinc diffused into gallium antimonide vacancies in the gallium antimonide is less than its thermal equilibrium value in the crystal. Gallium atoms diffuse in the lattice, so that the zinc that diffuses by occupying gallium vacancies will form a high-concentration diffusion region, and what is useful for making batteries is the tail zinc that is formed by kicking out the gallium atoms in the lattice. diffusion area. The traditional open diffusion method using zinc-antimony alloy as the diffusion source refers to the method that zinc diffuses arsenic atoms in gallium arsenide, which is easy to overflow and enters arsenic element in the diffusion source, while in gallium antimonide crystal, it is Gallium, a group III element, is easy to overflow, so the addition of antimony atoms in the diffusion source does not have much effect on the diffusion curve. However, the sealed diffusion method with the zinc-gallium alloy diffusion source adopted in the preparation method of the selective emitter gallium antimonide infrared battery of the present invention, due to the presence of gallium atoms in the diffusion source, effectively curbs the diffusion process. The overflow of gallium atoms in the gallium antimonide crystal prevents the generation of a high-concentration zinc diffusion layer on the surface.

Based on the above principles, the sealed zinc diffusion method using zinc-gallium alloy as a diffusion source in the present invention has the following advantages compared with the traditional open-type diffusion method using a zinc-antimony alloy as a diffusion source: it can effectively contain the diffusion of antimony The high-concentration diffusion layer on the surface of the gallium nitride wafer solves the problem that the precise corrosion is difficult to control after the traditional diffusion process, so that the electrical performance of the produced gallium antimonide infrared battery remains stable; the selective emitter gallium antimonide infrared battery of the present invention is used The zinc diffusion method proposed in the preparation method of the present invention only needs to pass a small amount of argon as flushing gas in the process of vacuuming, and does not need to pass into any protective gas during the diffusion process. Therefore, the preparation method of the present invention is also The preparation cost of gallium antimonide infrared battery can be reduced.

The selective emitter gallium antimonide infrared battery of the present invention prepared by the method of the present invention is formed by direct diffusion because the single diffusion front zinc concentration curve inside the battery is formed by direct diffusion, and the concentration of more than 95% of the zinc diffusion layer inside the battery is lower than 10 ²⁰ cm ^-3 Atoms/cm ^-3 single-diffusion front zinc concentration curve, so the lifetime of photo-generated minority carriers that can generate current will not be reduced due to excessive doping concentration, so photons in the near-infrared band can be effectively converted into electrical energy; and The gallium antimonide cell prepared by the traditional zinc diffusion process has a double-diffusion front zinc curve with a high-concentration layer on the surface. The high-concentration diffusion front on the surface must be removed by precise etching to improve the lifetime of photogenerated minority carriers. The corrosion process is difficult to control. Different batches of batteries have different zinc diffusion curves inside, resulting in unstable output performance of batteries of different batches, which is not conducive to the preparation of battery components.

Description of drawings

Fig. 1 is a schematic diagram of the diffusion system required for the sealed diffusion method of the zinc-gallium alloy used in the present invention.

Fig. 2 is a comparison diagram of the diffusion curve obtained by the sealed diffusion method using the zinc-gallium alloy in the present invention and the diffusion curve obtained by the open zinc diffusion method using the traditional zinc-antimony alloy as the diffusion source.

Fig. 3 is a schematic diagram of the structure of gallium antimonide infrared cells prepared by the traditional open diffusion method.

Fig. 4 is a schematic diagram of the structure of the gallium antimonide infrared battery prepared by the novel sealed diffusion method of the present invention.

Fig. 5 is a diagram of the internal quantum efficiency of the gallium antimonide infrared battery prepared by the novel sealed diffusion method of the present invention.

detailed description

Example 1:

Fig. 1 has provided the schematic diagram of the diffusion system required by the sealed diffusion method of zinc-gallium alloy in the present invention. The following describes the zinc diffusion preparation method of the selective emitter gallium antimonide infrared battery in this embodiment in conjunction with the accompanying drawings, which specifically includes the following steps:

In the first step, the N-type gallium antimonide wafer containing tellurium Te with a concentration of 2 to 7×10 ¹⁷ cm ^-3 and a <100> crystal orientation is successively placed in xylene, acetone and ethanol for cleaning, and then cleaned with a concentration of 5-20% dilute hydrochloric acid to remove oxides on the surface of the wafer, and finally rinse with deionized water and blow dry with nitrogen;

In the second step, a silicon dioxide layer with a thickness of 0.11 μm is deposited on the wafer by plasma chemical vapor deposition, and then the diffusion area in the center of the wafer is defined by a photolithography process, and the silicon dioxide layer in this central area is used The corrosive solution is soaked and removed to obtain a gallium antimonide wafer that can be used for zinc diffusion, that is, a gallium antimonide wafer for diffusion preparation; the corrosive solution used to soak and remove silicon dioxide is a conventional formula, that is, according to 3ml of hydrofluoric acid: ammonium fluoride 6g: 10ml deionized water for proportioning;

The third step, as shown in Figure 1: put the diffusion source zinc-gallium alloy 1 and the diffusion preparation gallium antimonide wafer 2 prepared in the second step into the quartz tube 3, close the valve 4 connected to the argon gas 6, Open the valve 5 connected to the vacuum pump 7, and evacuate the quartz tube to 5-10 Pa; then close the valve 5, open the valve 4, and let in argon gas with a flow rate of 1-3 L/min until the pressure inside the quartz tube rises to an atmospheric pressure. Close valve 4, open valve 5 to vacuumize again, then close valve 5 to maintain the vacuum state in the quartz tube; the entire quartz tube 3 is placed in the diffusion furnace 8, and the two ends of the quartz tube should exceed the boundary of the diffusion furnace by 2 to 4 cm , and the excess part is filled with insulation materials; the two ends of the quartz tube should not exceed the boundary of the diffusion furnace for too long, otherwise zinc-gallium vapor will condense at both ends;

Step 4: Turn on the diffusion furnace, raise the temperature to 500°C at a rate of 5-10°C/min, and maintain the above temperature for 2 hours; after the diffusion process is over, open the top cover of the diffusion furnace, and use the built-in fan of the diffusion furnace for rapid cooling After reaching room temperature, take out the diffused gallium antimonide wafer;

Figure 2 shows the diffusion curve obtained by the sealed diffusion method of zinc-gallium alloy and the open zinc diffusion method obtained by the traditional zinc-antimony alloy as the diffusion source after the temperature rise rate is 10°C/min and the diffusion temperature is 500°C. Diffusion curve comparison plot. Now the zinc concentration curve in the gallium antimonide wafer should be shown in curve 12 in Fig. 2, can find, adopt the zinc curve that the sealing type diffusion method of the present invention obtains to only have single diffusion front; If adopting the diffusion source to be zinc - The open diffusion method of antimony alloy, when the diffusion conditions are the same, a double diffusion front diffusion curve 11 with an inflection point 10 will be generated after diffusion.

The fifth step is to protect the front side of the N-type GaSb wafer with only a single diffusion front zinc curve obtained in the fourth step with a photoresist by using spin coating technology, and the immersion ratio is 3.5g of tartaric acid: 4mL of hydrogen peroxide: hydrogen fluoride Acid 1mL: 400mL of deionized water is used to remove the P-type layer on the periphery of the wafer and the back of the etching solution for 1 to 3 minutes, then soak in acetone solution to remove the photoresist; and then prepare it by magnetron sputtering method Electrodes for battery formation: first deposit Ti50nm/Pt50nm/Ag250nm on the back of the substrate in sequence as the back electrode, and heat to 280°C under a vacuum of 1 to 10×10 ^-4 Pa for 10 minutes; then The front side uses photolithography to define the area where electrodes need to be deposited, that is, the area where electrodes need to be prepared is exposed and the area where the photoelectric effect is generated is covered with photoresist, and then Pt50nm/Ag250nm is sequentially deposited on the front side of the substrate as the front electrode, and finally Remove the thin film layer in the photoelectric effect area on the front of the battery by using the stripping-floating technique; prepare the upper and lower electrodes of the battery by the above method;

The sixth step is to put the gallium antimonide battery with the electrode prepared into the ammonium sulfide solution for passivation for 5-10 minutes, so as to reduce the dangling bonds on the surface of the wafer;

The seventh step is to measure with a quantum efficiency tester to obtain the quantum efficiency of the battery. Fig. 5 is a diagram of the internal quantum efficiency of the gallium antimonide infrared battery prepared by the sealed diffusion method of the zinc-gallium alloy in the present invention. As shown in FIG. 5 , it can be found that the battery prepared by the present invention has good spectral responsivity in the band of 300-1700 nm, and its quantum efficiency reaches 70-85% in the near-infrared band.

In the embodiment of the present invention, secondary ion mass spectrometry is used to test the concentration distribution curve of zinc in gallium antimonide wafers. The measured zinc concentration is a single diffusion front, and the concentration above 95% of the area inside the curve is lower than 10 ²⁰ cm ^-3 Atoms/cm ^-3 , such a doping concentration level will not cause a large amount of recombination of photogenerated minority carriers, which is beneficial to the preparation of gallium antimonide infrared cells.

The preparation method of the zinc-gallium alloy diffusion source described in the present invention is to adopt zinc with a weight ratio of 3% and a purity of 99.9999% and gallium with a weight ratio of 97% and a purity of 99.9999% to be placed in a quartz tube at the same time, and vacuumize And seal it, put it into a heating furnace and heat it to 600° C. and keep it for 24 hours, so that the two elements can be fully mixed, and the zinc-gallium diffusion source required by the present invention can be obtained after cooling.

The selective emitter gallium antimonide infrared battery of the present invention prepared by the above method comprises: a gallium antimonide wafer having a PN junction formed on the surface zinc diffusion layer, the bottom of the wafer adopts Ti/Pt/Ag as the back electrode, Pt/Ag is used as the positive electrode on the wafer, and a silicon dioxide anti-reflection layer is deposited on the positive electrode; the zinc diffusion layer of the battery has a concentration of less than 10 ²⁰ cm ^-3 Atoms/cm ^-3 in more than 95% of the area Zinc concentration profile at the single diffusion front.

Comparative example 1:

If the open-type diffusion method is adopted in which the diffusion source is zinc-antimony alloy, the diffusion temperature is still 500°C, and the diffusion takes 2 hours. After diffusion, a double-diffusion front diffusion curve 11 with an inflection point 10 will be generated. The prepared battery structure is shown in Figure 3 . Wherein the electrode 13 on the upper surface of the N-type wafer 19 and the zinc diffusion region 17 on the surface of the light receiving part 14 all have a double diffusion front 18, and the region 16 before the intersection point 15 of the two diffusion fronts needs to be accurately etched to improve the quantum efficiency. Without corrosion, the internal quantum efficiency of the battery is only 15-25%. However, this corrosion process is very difficult to control, because the high-concentration area on the surface is very deep, the corrosion time is long, and the concentration of the corrosion solution decreases with the extension of the corrosion time. The corrosion rate also changes accordingly, and it is difficult to accurately etch to the junction of the two diffusion fronts. 20 in FIG. 3 is the lower electrode of the battery.

Fig. 3 is a schematic structural diagram of a gallium antimonide battery prepared by a traditional open diffusion method as a comparison; Fig. 4 is a schematic structural diagram of a gallium antimonide battery prepared by a new sealed diffusion method according to the present invention. As can be seen from Fig. 4, the upper electrode 21 of the N-type wafer 25 obtained by the novel sealed diffusion method in the present invention and the surface layer region 24 below the light-receiving part 22 are all zinc concentration curves 23 with only a single diffusion front. It is necessary to use ammonium sulfide to carry out simple surface passivation to prepare a gallium antimonide battery with a quantum efficiency of 70-85% in the near-infrared band; the lower electrode of the battery is shown as 26; and it can be seen from Figure 3 The electrode 13 on the upper surface of the N-type wafer 19 and the zinc diffusion region 17 on the surface layer of the light receiving part 14 obtained by the open diffusion method of the traditional zinc-antimony alloy have double diffusion fronts 18, which require a precise corrosion process to absorb the light. The high-concentration layer on the surface of area 14 is etched away until it has the same shape as curve 23. Since the corrosion rate is related to temperature and the concentration of the corrosive solution, the concentration of the corrosive solution will gradually decrease during the etching process, so it is difficult to achieve precise etching . Different batches of batteries prepared by the above-mentioned existing traditional methods have large differences in internal curve shapes, which will cause large differences in output power of different batches of batteries. However, in the gallium antimonide battery product of the present invention obtained by the novel sealed diffusion preparation method of the present invention, the zinc concentration curve at the single diffusion front is directly formed through the diffusion process without using precise corrosion, which improves the stability and stability of the battery performance output. Controllability of the preparation process.

Claims (3)

1. A method for preparing a selective emitter gallium antimonide infrared battery, comprising cleaning the gallium antimonide wafer, preparing a silicon dioxide diffusion protection layer around the front of the wafer, preparing a PN junction by zinc diffusion, and removing the back and peripheral P-type layers , preparation of electrodes, surface passivation, preparation of anti-reflection layer; characterized in that: zinc-gallium alloy is used as a diffusion source for sealed zinc diffusion to form a zinc concentration curve with only a single diffusion front in an N-type gallium antimonide wafer, specifically Including the following steps: The first step is to put the N-type gallium antimonide wafer with tellurium Te concentration of 2-7×10 ¹⁷ cm ^-3 and <100> crystal orientation into xylene, acetone and ethanol successively for cleaning, and then use mass ratio Dilute hydrochloric acid with a concentration of 5-20% removes oxides on the surface of the wafer, and finally washes in deionized water and blows dry with nitrogen; The second step is to deposit a layer of silicon dioxide with a thickness of 0.11 μm on the wafer by plasma chemical vapor deposition, and then use a photolithography process to define the diffusion area in the center of the wafer, and use the silicon dioxide layer in this central area with The corrosive solution is soaked and removed to obtain a gallium antimonide wafer that can be used for zinc diffusion, that is, a gallium antimonide wafer for diffusion preparation; the corrosive solution used to soak and remove silicon dioxide is a conventional formula, that is, according to 3ml of hydrofluoric acid: ammonium fluoride 6g: 10ml deionized water for proportioning; The third step is to put the diffusion prepared GaSb wafer prepared in the second step and the diffusion source zinc-gallium alloy into the quartz tube in the diffusion furnace, vacuumize to 5-10Pa, and the flow rate is 1-3L/ Min of argon until the pressure in the quartz tube returns to an atmospheric pressure; then close the argon valve and continue vacuuming to 5-10Pa, close the valve connected to the vacuum pump to maintain the vacuum state in the quartz tube, and increase the temperature at a rate of 5-10°C/min to 450～500℃, keep a certain temperature point in the above temperature range for 1～3h, so that the zinc vapor diffuses into the wafer; when the high temperature process of maintaining this constant temperature point in the diffusion furnace is over, open the top cover of the diffusion furnace and use The built-in fan in the furnace quickly cools down to room temperature to end the diffusion process, and then takes out the diffused GaSb wafer, which is an N-type GaSb wafer with only a single diffusion front zinc curve inside; The fourth step is to protect the front of the N-type gallium antimonide wafer with only a single diffusion front zinc curve obtained in the third step with a photoresist by using spin coating technology, and the immersion ratio is 3.5g of tartaric acid: 4mL of hydrogen peroxide: hydrogen fluoride Acid 1mL: 400mL of deionized water is used to remove the P-type layer on the periphery of the wafer and the back of the etching solution for 1 to 3 minutes, then soak in acetone solution to remove the photoresist; and then prepare it by magnetron sputtering method Electrodes for battery formation: first deposit Ti50nm/Pt50nm/Ag250nm on the back of the substrate in sequence as the back electrode, and heat to 280°C under a vacuum of 1 to 10×10 ^-4 Pa for 10 minutes; then The front side uses photolithography to define the area where electrodes need to be deposited, that is, the area where electrodes need to be prepared is exposed and the area where the photoelectric effect is generated is covered with photoresist, and then Pt50nm/Ag250nm is sequentially deposited on the front side of the substrate as the front electrode, and finally The thin film layer in the area where the photoelectric effect is generated on the front of the battery is removed by stripping-floating technology, and the upper and lower electrodes of the battery are prepared; The fifth step is to soak the gallium antimonide battery with the upper and lower electrodes in the ammonium sulfide solution for 5-10 minutes to passivate the surface; The sixth step is to deposit a layer of 0.15 μm silicon nitride layer on the front of the battery as an anti-reflection film by plasma chemical vapor deposition to obtain a selective emitter gallium antimonide infrared battery. 2. the preparation method of selective emitter gallium antimonide infrared battery as claimed in claim 1, is characterized in that the preparation method of described zinc-gallium alloy diffusion source is: be that 3% zinc with a purity of 99.9999% and Gallium with a weight ratio of 97% and a purity of 99.9999% is placed in a quartz tube at the same time, vacuumed to 5-10Pa and sealed, then placed in a heating furnace and heated to 600°C for 24 hours to fully mix the two elements , which is the desired Zn-Ga diffusion source after cooling. 3. a selective emitter gallium antimonide infrared cell prepared by the method as claimed in claim 1, comprising: a gallium antimonide wafer having formed a PN junction with a zinc diffusion layer on the surface, and the bottom of the wafer adopts Ti/Pt/ Ag is used as the back electrode, and Pt/Ag is used as the positive electrode above the wafer, and a silicon dioxide antireflection layer is deposited on the positive electrode; it is characterized in that the zinc diffusion layer in the gallium antimonide infrared battery has a single diffusion front shape.