CN208208780U

CN208208780U - High temperature and pressure dry and wet oxidation unit for anti-PID performance photovoltaic cell

Info

Publication number: CN208208780U
Application number: CN201820754203.3U
Authority: CN
Inventors: 朱广和; 赵雅; 费春燕; 赵沁; 王燕; 赵枫; 李向华
Original assignee: JIANGSU ECONESS ENERGY CO Ltd
Current assignee: JIANGSU ECONESS ENERGY CO Ltd
Priority date: 2018-05-19
Filing date: 2018-05-19
Publication date: 2018-12-07
Anticipated expiration: 2028-05-19

Abstract

The utility model relates to a kind of high temperature and pressure dry and wet oxidation units for anti-PID performance photovoltaic cell, including oxidation furnace, oxygen cylinder, O₂Gas tank and HCL gas tank are equipped with quartz ampoule in the oxidation furnace, are respectively provided with the thermocouple of heating and in the quartz ampoule for placing the section S1 of graphite boat, the O₂Gas tank and HCL gas tank pass through pipeline respectively and are connected with quartz ampoule, and are respectively equipped with O on respective pipeline₂Gas straight autocontrol valve and HCL gas autocontrol valve, the oxygen cylinder) it is equipped with thermometer, and it is equipped with one and O₂The escape pipe that the air inlet pipe and one that gas tank is connected to are connected to quartz ampoule, the oxygen cylinder are placed in heating oil tank, and heating oil tank is placed on electric furnace, in the oxygen cylinder and quartz ampoule and O₂It is respectively equipped with wet oxygen autocontrol valve on the tank connected pipeline of gas and dry oxygen is passed through oxygen cylinder autocontrol valve.

Description

High temperature and pressure dry and wet oxidation unit for anti-PID performance photovoltaic cell

Technical field

A kind of high temperature and pressure dry and wet oxidation unit for anti-PID performance photovoltaic cell of the utility model, belongs to the sun It can photovoltaic cell field.

Background technique

Domestic and international photovoltaic industry realizes widespread adoption and technological progress in recent years, but since photovoltaic industry is always by political affairs Mansion is helped so far, there are problems that cannot be neglected technology and the market risk etc. always.In fact, photovoltaic in recent years Assembly property improves the result that should be attributed to the fact that technological innovation and process optimization at different levels in crystalline silicon industrial chain.However, with crystalline substance Body silicon solar cell photoelectric conversion efficiency room for promotion gradually becomes smaller, and promotion slows, it has been found that continues to pass by optimization The solar battery technology of system and technique further increase the efficiency of photovoltaic cell with regard to more and more difficult.It is each in middle America and Europe etc. The numerous and confused curtailment of subsidy of government of state, day the market demands such as Europe just actively require relatively low ground intermediate item to turn to component efficiency Higher roof intermediate item is required instantly to component efficiency, by the innovation of in-depth photovoltaic technology and application, is reduced cost, is mentioned High efficiency, it is final to realize perfect market cheap internet access, become the final outlet of photovoltaic industry.To some degree, low The development of cost high efficiency photovoltaic cell determines to become main energy sources instead of traditional energy, and whether this main energy sources is light Volt, and how substitute speed? in this respect, revolutionary high efficiency technical just receives more and more attention.

Several years in past, photovoltaic industry rely primarily on the reduction of product price in terms of improving cost performance, continue to drop afterwards now The space of low price very little, photovoltaic industry will be directed generally to improve battery component performance, that is, greatly improve photovoltaic Component transfer efficiency, lifting assembly power itself reduce unit cost of electricity-generating with this indirectly, improve photovoltaic energy cost performance.

Solar battery is a kind of very ideal renewable clear energy sources, in practical applications, due to single crystalline silicon Solar components output voltage and power are relatively low, life or production needs are not able to satisfy, so needing to concatenate multiple components. Under long-term action of high voltage, there are leakies between glass and encapsulating material in component, so that a large amount of charge Na+ ions are rich Collection causes the antireflective coating failure of surface purifying before this, then PN junction fails, and continues assembly property on cell piece surface Decaying.

Currently, the conventional batteries piece of non-anti- PID is surveyed under conditions of double 85, reversed 1000V, 96h in photovoltaic industry Examination, power attenuation rate reach 3% or more, form great obstruction to effective popularization of photovoltaic industry, are that battery chip technology needs The technology emphasis captured.In recent years, PID have become an important factor for photovoltaic cell quality is complained by domestic and international terminal producer it One, it can cause one piece of 50% or more photovoltaic power decaying when serious, so that the power output of entire component is influenced, Therefore the PID phenomenon of photovoltaic cell is increasingly by the attention of photovoltaic industry.Research and the solution anti-PID effect of photovoltaic cell are asked Topic, can effectively promote photovoltaic power generation income.

From some power stations, actual use shows that the system voltage of photovoltaic generating system seems to exist to crystal silicon cell component There is lasting PID effect, the crystal silicon cell based on silk-screen printing is led by the circuit that encapsulating material forms module frame The telegram in reply stream of cause is confirmed to be the main reason for causing the effect.Currently in order to PID loss value is effectively reduced, mainly from electricity Pond, component, system three aspect are realized.And these three aspect battery-ends are emphasis, are to be not required to increase cost and can generate Continuous action.From the point of view of battery-end, the technique for changing cell piece purifying antireflection film layer is one of main direction of studying.Change electricity The refractive index of pond antireflection layer can reduce the generating efficiency of cell piece, do not improving production cost and do not reducing efficiency substantially In the case of, reach anti-PID purpose.And thermal oxidation technique is used to generate SiO₂, can effectively achieve the effect that anti-PID.

It, usually all can be by increasing the refractive index of silicon nitride film, but this mode for the anti-PID effect for increasing cell piece The decrease in efficiency 0.1%-0.2% for making cell piece is not a kind of way of economy.Fundamentally to reduce PID loss Mainly also depend on the innovation that technique is made in cell piece.Later by the study found that SiO₂Film is in crystal silicon cell technique It may be used as screening, cell piece protected not influenced by the external world, increase the anti-PID effect of cell piece, it can be by plating nitride film One layer of SiO of preceding growth₂The mode of layer is realized, and SiO₂Layer can also play the role of surface purifying to crystalline silicon battery plate.Separately The outer technique can and be deposited with other techniques, and all crystal-silicon battery slices include that conventional unconventional battery blade technolgy can be superimposed with this It uses.How to effectively reduce PID loss value becomes the key of assembly quality guarantee.Not with photovoltaic products requirement Disconnected to improve, the continuous enhancing competed in the industry, the performance of cell piece is the key that determine success or failure in the industry competition of enterprise's future, this is just It is required that also needing the performance quality of raising cell piece while cell piece producer constantly reduces cost.Therefore seek a kind of anti-PID Performance photovoltaic cell and preparation method thereof is particularly important.

Utility model content

Technical problem to be solved in the utility model is that one kind is provided for the above-mentioned prior art for anti-PID performance light Lie prostrate the high temperature and pressure dry and wet oxidation unit of cell piece, not only can high temperature and pressure dry and wet thermal oxide, chemical deposition electrolytic oxidation and anti- It should sputter；And the SiO that high temperature and pressure dry and wet thermal oxide generates₂, equipment is simple, easy to operate, it is produced at film it is fine and close Performance height and anti-PID effect are good.The utility model can realize the promotion of 0.1% or more cell piece transfer efficiency, and component is same Test condition test PID loss can be down to 1% hereinafter, anti-PID effect is obvious, better than other techniques by original 3% or more. Ensure that terminal photovoltaic plant service life increases by 5 years, greatly improves the economic benefit of photovoltaic plant.

The technical scheme in the invention for solving the above technical problem are as follows: one kind is used for anti-PID performance photovoltaic cell High temperature and pressure dry and wet oxidation unit, the innovative technology use high temperature and pressure dry and wet thermal oxide anti-PID SiO generated₂Layer It is, as in the oxidizing atmosphere of oxidant, to there is oxidant and silicon atom to react in silicon face with steam, wet oxygen or dry oxygen It is generated, silicon atom consumes in thermal oxidation process, and so that the surface of silicon is shifted to the reaction continued on repeatedly in vivo will It is carried out on this silicon face.The SiO that steam oxidation generates₂Layer short texture, water content is more, poor to the hidden ability of impurity, But the speed of growth is fast；The resulting membrane structure of dry-oxygen oxidation is fine and close, dry, uniform reproducible, and screening ability is strong, purifying effect Fruit is good, but the speed of growth is slow.And the innovative method for oxidation that the technique uses: high temperature and pressure dry and wet thermal oxide → dry oxygen → wet Oxygen → dry oxygen → wet oxygen → dry oxygen replaces multiple method for oxidation to obtain not only thick but also finer and close SiO₂Layer.This process innovation type oxygen The long film situation of metaplasia is between steam oxidation and dry-oxygen oxidation, the advantages of can having both two kinds of growths simultaneously, ensure that into High rate of film build is realized while film compactness again on the one hand ensure production capacity, on the other hand improve anti-PID effect.

It is preferred: one layer of ideal SiO is grown before plating silicon nitride film₂Layer, reaches and cell piece is effectively protected not by outer Boundary's condition influences, it is ensured that the quality of cell piece decays with cell piece PID is slowed down, while playing and purifying to cell piece surface Operation, improve the efficiency of cell piece and the market competitiveness of enterprise.

It is preferred: multiple method for oxidation being replaced by dry oxygen → wet oxygen → dry oxygen → wet oxygen → dry oxygen, has obtained structure cause Close, dry, uniform reproducible SiO₂Layer, effectively sheltered the gloves remained on surface of cell piece in production process print, Rolling wheel stamp improves the yields of cell piece, while the consistency that forms a film is conducive to well production line control.

It is preferred: HCL gas being added in oxidation process, leads to HCL gas simultaneously in logical wet oxygen, utilizes the halogen in HCL gas The impurity of cell silicon chip, is transformed into readily volatilized chloride by race Elements C L, to play the effect to silicon wafer gettering, is had Effect increases cell piece short circuit current.

Preferred: novelty uses high temperature and pressure dry and wet oxidation technology, and oxidation furnace temperature rises to 900 DEG C, and pressure is raised to 400Pa high-temperature high-pressure state, oxidation rate rate rises to 18% by original 12% at this time, and the film forming speed of oxidation film mentions significantly It rises, while reducing the redistribution of impurity and the displacement of PN junction, it is suppressed that the raw defect of the rust of oxidation process, stress and impurity divide again Cloth effect.

Preferred: high temperature and pressure dry and wet method for oxidation and processing technology routine are as follows:

Step 1: oxidation furnace is heated up to 900 DEG C, after vacuum pressure reaches 400Pa and stablizes, and oxygen cylinder temperature reaches 90 DEG C And after stablizing, above-mentioned temperature, pressure should be in stable state in 3 minutes.

Step 2: in the case where above-mentioned furnace temperature, pressure, bottle temperature are in stable state, being first passed through 60CC/ point dry oxygen, clean/ Purge quartz ampoule.

Step 3: silicon wafer is placed on push-in boiler tube flat-temperature zone on quartz boat, closes fire door.

Step 4: start to be passed through dry oxygen after temperature, pressure stabilization up to standard, the time is 4 minutes.

Step 5: start to be passed through wet oxygen, the time is 27 minutes, while HCL gas is added, and the time is 8 minutes.

Step 6: being passed through dry oxygen again, and the time is 4 minutes.

Step 7: being passed through wet oxygen again, and the time is 27 minutes, while HCL gas is added, and the time is 8 minutes.

Step 8: being passed through dry oxygen again, and the time is 4 minutes.

Step 9: opening fire door, pulls out quartz boat, takes out silicon wafer.

And the utility model product in addition to above-mentioned high temperature and pressure dry and wet oxidation technology innovation it is different from original process other than, Qi Tazhu Technology is wanted not become, dominating process route is as follows:

Primary cleaning → diffusion → secondary cleaning → high temperature and pressure dry and wet aoxidizes (PID) → PECVD → silk-screen printing → survey Examination is sorted → is packed and stored.

Compared with the prior art, the advantages of the utility model are:

1, high temperature and pressure dry and wet aoxidizes anti-PID SiO generated₂Layer is using aqueous vapor, wet oxygen or dry oxygen as oxidant Oxidizing atmosphere in, reacted and generated in silicon face by oxidant and silicon atom.Silicon atom high temperature and pressure dry and wet oxygen It is consumed during changing, so that the surface of silicon is shifted to the reflection continued in vivo will carry out in this silicon face.The high temperature of silicon wafer The oxidation of high pressure dry and wet is carried out according to following chemical reaction:

Gaseous species	Reflection formula	Speed
			O₂	Si+O₂→SiO₂	Slowly
H₂Or (H₂+O₂)	Si+2H2O→SiO+2H₂	Fastly

(1) dry-oxygen oxidation: the Si atomic reaction of oxygen molecule and the surface Si under high temperature and pressure generates SiO₂Beginning layer, hereafter, Established SiO₂Layer prevents oxygen molecule to contact with the direct of silicon face, and oxygen molecule passes through SiO with diffusion way₂Layer reaches SiO₂- Si reacts at interface with silicon atom, generates new SiO₂Layer, makes SiO₂Layer constantly thickens.

(2) steam oxidation: oxygen enters quartz by the oxygen cylinder equipped with high purity deionized water by the formation of bubble Pipe, therefore, the oxygen into quartz ampoule have steam, and the content of steam is determined by the temperature of oxygen cylinder and the speed of oxygen stream It is fixed.Substance due to participating in oxidation is the mixture of water and oxygen, so its oxidation rate is much faster than dry-oxygen oxidation, in water When vapour aoxidizes, the SiO of growth₂Thickness degree is removed to be had outside the Pass with the temperature of oxidation, time, also related with water content in oxygen, one Under fixed oxygen flow, moisture content oxygen cylinder bath temperature.

2, in the above method for oxidation, the SiO of steam oxidation generation₂Layer short texture, water content is more, to impurity screening ability It is poor, but the speed of growth is fast；The resulting membrane structure of dry-oxygen oxidation is fine and close, dry, uniform reproducible, and screening ability is strong, Purification effect is good, but the speed of growth is slow.And the Novel high-temperature high-pressure dry and wet oxidizing process of the utility model: high temperature and pressure dry and wet oxidation → dry oxygen → wet oxygen → dry oxygen → wet oxygen → dry oxygen replaces multiple method for oxidation to obtain not only thick but also fine and close SiO₂Layer, this mode The film situation of oxidation growth is between steam oxidation and dry-oxygen oxidation, the advantages of can receiving two kinds of growth patterns, ensure that High rate of film build is realized while film formation compactness again, to ensure production capacity and quality.

3, by high temperature and pressure dry and wet method for oxidation, excellent SiO is obtained₂Layer is to ensure the anti-PID effect of crystal silicon chip/component Fruit, PID decaying, which is down to 1%, under standard test condition has larger decline 3% or more hereinafter, decaying with traditional handicraft product, It ensures crystal silicon chip/component efficiency stabilization, while improving 0.1% or more the transfer efficiency of cell piece, significantly improve Traditional technology is easy to generate gloves print, the fouling problems such as rolling wheel stamp on cell piece surface, by the appearance yield of cell piece from 97.73% is increased to 99.75%, improves 2.02%.

2% or more PID decaying is reduced due to aoxidizing using high temperature and pressure dry and wet and improves cell piece transfer efficiency 0.1% or more, and make 3% or more photovoltaic plant economic benefit increase, service life increases by 5 years or more；Simultaneously because cell piece Appearance yield improve 2.02%, and increase 2% or more cell piece production industry economic benefit.

Detailed description of the invention

Fig. 1 is the structural schematic diagram of the utility model embodiment high temperature high pressure dry and wet oxidation unit.

Specific embodiment

The utility model is described in further detail below in conjunction with figure embodiment.

As shown in Figure 1, the anti-PID performance photovoltaic cell of one of the present embodiment the preparation method is as follows: referring to Fig. 1. What the utility model was realized by the high temperature and pressure dry and wet oxidation furnace of self-control repacking.The oxidation furnace is original single dry oxygen Oxidation technology device and the organic transformation of steam oxidation process unit are combined into a new high temperature and pressure dry and wet oxidation technology device. Its structure are as follows: oxidation furnace 1, quartz ampoule 2, the section S1 3, thermocouple 4, electric furnace 5, oxygen cylinder 6, wet oxygen furnace temperature meter 7, O₂Gas stream Meter 8, O₂Gas tank 9, HCL gas tank 10, O₂Gas filter bulb 11, HCL gas autocontrol valve 12, O₂Gas straight is controlled automatically Valve 13, O processed₂Gas leads to wet oxygen producer automatic valve 14, and wet oxygen leads directly to autocontrol valve 15, HCL gas flowmeter 16, and dry oxygen is straight Through-flow meter 17, wet oxygen straight through flow meter 18.Realize that the utility model technological innovation place is as follows by above-mentioned facility:

1) one layer of ideal SiO is grown before plating silicon nitride film₂Layer: one layer of ideal SiO is grown before plating silicon nitride film₂Layer, More efficiently cell piece can be protected not influenced by the external world, it is ensured that the quality of cell piece and to slow down cell piece PID and decline Subtract, while having play a part of to improve cell piece surface passivation the efficiency of cell piece and the market competitiveness of enterprise.

2) multiple method for oxidation is replaced by dry oxygen → wet oxygen → dry oxygen → wet oxygen → dry oxygen, has obtained compact structure, has done Dry, uniform reproducible SiO₂Layer has effectively covered the gloves print remained on surface of cell piece among production process, idler wheel Print, improve the yields of cell piece, while the consistency that forms a film it is good and be conducive to production line manage.

3) HCL gas is added in oxidation process: leading to HCL gas simultaneously in logical wet oxygen, utilizes the halogen in HCL gas The impurity of cell silicon chip is transformed into readily volatilized chloride by CL, to play the effect to silicon wafer gettering, is effectively increased The short circuit current of cell piece.

4) innovative use high temperature and pressure dry and wet oxidation technology, oxidation furnace temperature rise to 900 DEG C, and pressure is raised to 400Pa High-temperature high-pressure state, oxidation rate rises to 18% by original 12% at this time, and the film forming speed of oxidation film greatly promotes, and subtracts simultaneously The redistribution of impurity and the displacement of PN junction are lacked, it is suppressed that the raw defect of the rust of oxidation process, stress and dopant redistribution effect.

Tables 1 and 2 below is oxidation rate of silicon under the conditions of wet oxygen and dry oxygen:

Table 1: the wet-oxygen oxidation rate of silicon

Table 2: the dry-oxygen oxidation rate of silicon

Tables 1 and 2 is respectively the rate constant of silicon wet-oxygen oxidation and dry-oxygen oxidation.Wherein A and B is rate constant, B/ A is linear rate constant,

Although the speed of growth of dry oxygen method is very slow, the SiO of growth₂Membrane structure is fine and close, dry, uniformity and repetition Property is good, and due to SiO₂Surface contacts well with photoresist, and when photoetching is not easy floating glue.And although wet-oxygen oxidation rate is fast, There are more dislocation and etch pits on Si piece surface after oxidation, but also there is one layer to make SiO₂Surface is contacted with photoresist The silanol (Si-OH) of difference, therefore in production practice, generally use dry oxygen → wet oxygen → alternate mode of oxidizing of dry oxygen.This Kind is done, the alternating oxidation mode of wet oxygen solves the contradiction between growth rate and quality, makes the SiO of growth₂Film is preferably Meet the requirement of actual production.

Specific implementation step is as follows:

Step 1: the heating of oxidation furnace 1 is reached 900 DEG C by temperature-pressure, and vacuum pressure reaches 400Pa, wet oxygen producer 6 Heating reaches 90 DEG C；

Step 2: after oxidation furnace 1 and 6 temperature-pressure of oxygen cylinder reach setup parameter and stablize 3 minutes, it is straight to open dry oxygen Logical autocontrol valve 13, the dry oxygen of 60CC/ is passed through from oxygen gas tank 9 into oxidation furnace 1, will be clear in the quartz ampoule 2 in oxidation furnace 1 It washes/purges one time, be then shut off dry oxygen and lead directly to autocontrol valve 13；

Step 3: the silicon wafer with oxidation is placed on quartz boat, is then pushed into the flat-temperature zone of oxidation furnace 1, closes fire door, after Continuous equilibrium temperature and pressure, temperature is at 900 DEG C, and vacuum pressure is in 400Pa；

Step 4: it opens dry oxygen and leads directly to autocontrol valve 13, start to be passed through dry oxygen in oxidation furnace 14 minutes, then open Wet oxygen autocontrol valve 15 is passed through wet oxygen 27 minutes again in oxidation furnace 1, opens simultaneously HCL gas autocontrol valve 12 toward oxygen Change in furnace 1 and is passed through HCL gas 8 minutes；

Step 5: it opens dry oxygen and leads directly to autocontrol valve 13, be passed through dry oxygen in oxidation furnace 1 again 4 minutes, then again It opens wet oxygen autocontrol valve 15 and is passed through wet oxygen 27 minutes, it is logical toward oxidation furnace 1 to open simultaneously HCL gas autocontrol valve 12 again Enter HCL gas 8 minutes；

Step 6: the straight-through autocontrol valve 13 of dry oxygen is opened for the third time toward oxidation furnace 1 and is passed through dry oxygen 4 minutes, then will be done Oxygen leads directly to autocontrol valve 13, wet oxygen autocontrol valve 15 and HCL gas autocontrol valve 12 and is turned off；

Step 7: oxidation fire door is opened, it is standby that the well-oxygenated silicon wafer of high temperature and pressure dry and wet has been completed in pull-out quartz boat taking-up With.

And silicon wafer working process, other than the utility model technology, other techniques still use original process route such as Under:

Primary cleaning → diffusion → secondary cleaning → high temperature and pressure dry and wet aoxidizes (the utility model technology) → PECVD → silk Wire mark brush → testing, sorting → is packed and stored.

By the implementation of the utility model high temperature and pressure dry and wet oxidation technology, the anti-PID effect of cell piece greatly improved, Decay in standard test condition lower component PID measured power and drops to 1% hereinafter, greatly improving photovoltaic group by 3% or more The stability of part, utilizes SiO₂The excellent purification effect of film makes the transfer efficiency of cell piece improve 0.1% or more, solves Traditional technology is easy to generate gloves print on cell piece surface, the fouling problems such as rolling wheel stamp, by the appearance yield of cell piece from 97.73% is increased to 99.75%, improves 2.02%, improves 2% or more photovoltaic products economic benefit, improves photovoltaic electric 3% or more economic benefit of standing extends service life 5 years of photovoltaic plant or more, overall economic efficiency is greatly improved, into one Step pushed solar energy power generating be applied to development.

In addition to the implementation, the utility model further includes having other embodiments, all to use equivalents or equivalent The technical solution that alternative is formed, should all fall within the protection scope of the utility model claims.

Claims

1. a kind of high temperature and pressure dry and wet oxidation unit for anti-PID performance photovoltaic cell, it is characterised in that: including oxidation furnace (1), oxygen cylinder (6), O₂Gas tank (9) and HCL gas tank (10) are equipped with quartz ampoule (2) in the oxidation furnace (1), in institute It states in quartz ampoule (2) and is respectively provided with the thermocouple (4) of heating and for placing the section S1 (3) of graphite boat, the O₂Gas Body tank (9) and HCL gas tank (10) are connected by pipeline with quartz ampoule (2) respectively, and in O₂Gas tank (9) and HCL gas O is respectively equipped on body tank (10) respective pipeline₂Gas straight autocontrol valve (13) and HCL gas autocontrol valve (12), The oxygen cylinder (6) is equipped with thermometer (7), and is equipped with one and O₂The air inlet pipe and one and quartz ampoule of gas tank (9) connection (2) escape pipe being connected to, the oxygen cylinder (6) are placed in heating oil tank, and heating oil tank is placed on electric furnace (5), in the oxidation Bottle (6) and quartz ampoule (2) and O₂Wet oxygen autocontrol valve (15) is respectively equipped on the pipeline of gas tank (9) connection and dry oxygen is passed through Oxygen cylinder autocontrol valve (14).

2. a kind of high temperature and pressure dry and wet oxidation unit for anti-PID performance photovoltaic cell according to claim 1, It is characterized in that: in the O₂The escape pipe of gas tank (9) is equipped with O₂Gas filter bulb (11), to ensure dry oxygen purity.