CN119368403A - A cadmium chloride heat treatment method and device system for cadmium telluride battery - Google Patents

本发明属于电池制造技术领域，涉及一种碲化镉电池的氯化镉热处理方法及其装置系统，所述氯化镉热处理方法包括依次进行的碲化镉样品预热、氯化镉热喷涂和退火处理；其中，所述氯化镉热喷涂过程中，对氯化镉溶液和碲化镉样品分别进行加热；所述氯化镉热喷涂和退火处理分别进行至少1次。本发明提供的氯化镉热处理方法在喷涂之前对碲化镉样品及氯化镉溶液分别进行加热，使得到达碲化镉样品表面的主要是细化分散的氯化镉颗粒，从而改善了氯化镉膜层的连续性和微观均匀性，在提高碲化镉薄膜组件效率的同时降低了处理成本和设备成本。

The present invention belongs to the technical field of battery manufacturing, and relates to a cadmium chloride heat treatment method for a cadmium telluride battery and a device system thereof, wherein the cadmium chloride heat treatment method comprises sequentially preheating a cadmium telluride sample, thermal spraying of cadmium chloride, and annealing treatment; wherein, during the thermal spraying of cadmium chloride, the cadmium chloride solution and the cadmium telluride sample are heated respectively; and the thermal spraying of cadmium chloride and the annealing treatment are respectively performed at least once. The cadmium chloride heat treatment method provided by the present invention heats the cadmium telluride sample and the cadmium chloride solution respectively before spraying, so that the cadmium chloride particles reaching the surface of the cadmium telluride sample are mainly refined and dispersed, thereby improving the continuity and microscopic uniformity of the cadmium chloride film layer, and reducing the processing cost and equipment cost while improving the efficiency of the cadmium telluride thin film module.

Cadmium chloride heat treatment method and device system of cadmium telluride battery

Technical Field

The invention belongs to the technical field of battery manufacturing, relates to a cadmium telluride battery, and particularly relates to a cadmium chloride heat treatment method of the cadmium telluride battery and a device system thereof.

Background

At present, the cadmium telluride thin film solar cell plays an important role in energy conservation and emission reduction as the most successful commercial thin film solar cell technology. The cadmium chloride heat treatment process has a decisive effect on the preparation of the high-efficiency cadmium telluride thin film component, and the cadmium telluride absorbing layer material which is not subjected to the cadmium chloride heat treatment has a large number of defects and is easy to cause serious photo-generated carrier recombination, so that the component efficiency is poor and even is less than 10%. In comparison, the defects and the composites of the cadmium telluride absorbing layer material subjected to cadmium chloride heat treatment are remarkably reduced, and the component efficiency can be improved to more than 15 percent and up to 19 percent.

The existing cadmium chloride heat treatment process comprises a wet process and a dry process. The wet process is to coat cadmium chloride solution onto the surface of cadmium telluride through spraying, roller coating, soaking, etc. and then annealing at 300-550 deg.c in atmosphere or protecting atmosphere. The dry process adopts vacuum coating equipment to deposit a cadmium chloride film with the thickness of 100-1000nm on the surface of the cadmium telluride film, and then annealing treatment is carried out at the temperature of 300-550 ℃.

Compared with the wet process, the dry process can prepare a cadmium chloride film layer which is more uniformly distributed, is beneficial to improving the uniformity of cadmium chloride heat treatment and improves the efficiency of the cadmium telluride film assembly. However, the dry process requires high vacuum equipment and high equipment and component manufacturing costs. Comparatively, the wet process has simple process and low equipment and manufacturing cost, and is more beneficial to large-scale industrialization. However, the currently adopted wet process is difficult to obtain a cadmium chloride film layer with uniform distribution, and further has adverse effects on the heat treatment effect of cadmium chloride and the efficiency of a cadmium telluride component.

In order to further improve the uniformity of the wet cadmium chloride, the technicians in the field mainly improve the aspects of wet process, chlorine-containing solution formulation and the like, and improve the macroscopic distribution uniformity of the cadmium chloride to a certain extent. However, the micro-distribution uniformity on the micrometer scale is not improved, and most of cadmium chloride is not distributed on the surface of the cadmium telluride film, so that the uniform coverage of the whole area cannot be realized.

In addition, the wet process mainly comprises spraying and roller coating, wherein the spraying is in the form of atomized liquid drops to reach the cadmium telluride film surface, the roller coating is in the form of cadmium chloride solution to reach the cadmium telluride film surface, and then the cadmium chloride solution volatilizes and cadmium chloride is crystallized and separated out, and in the crystallization process, the chloridized cadmium electrode is easy to agglomerate to form dispersed particles, so that the film layer is discontinuous and is not completely covered.

Therefore, how to provide a cadmium chloride heat treatment method for a cadmium telluride battery, improve the continuity and microscopic uniformity of a cadmium chloride film layer, improve the efficiency of the cadmium telluride film assembly, and reduce the treatment cost and the equipment cost at the same time, is a problem which needs to be solved by the current technicians in the field.

Disclosure of Invention

Aiming at the defects existing in the prior art, the invention aims to provide a cadmium chloride heat treatment method and a device system thereof for a cadmium telluride battery, which improve the continuity and micro-uniformity of a cadmium chloride film layer, and reduce the treatment cost and equipment cost while improving the efficiency of the cadmium telluride film assembly.

In order to achieve the aim of the invention, the invention adopts the following technical scheme:

In a first aspect, the invention provides a cadmium chloride heat treatment method of a cadmium telluride battery, which comprises the steps of preheating a cadmium telluride sample, thermally spraying and annealing the cadmium telluride sample sequentially.

In the cadmium chloride thermal spraying process, a cadmium chloride solution and a cadmium telluride sample are heated respectively, and the cadmium chloride thermal spraying and annealing treatment are carried out at least 1 time respectively.

According to the cadmium chloride heat treatment method provided by the invention, the cadmium telluride sample and the cadmium chloride solution are heated respectively before spraying, so that atomized cadmium chloride droplets are subjected to high temperature when migrating to the surface of the cadmium telluride sample, a solvent (such as water or ethanol) is gasified, and finally the mainly refined and dispersed cadmium chloride particles on the surface of the cadmium telluride sample are finally reached, and the tiny solid particles are directly adsorbed on the surface of the cadmium telluride film to form a film, so that crystallization and agglomeration effects of the droplets are avoided, and the formation of dispersed large particles is prevented, and the sample high temperature is also beneficial to transverse migration of small particles (reaction precursors) in the initial nucleation process of the film formation, and the continuity and microscopic uniformity of the cadmium chloride film layer are remarkably improved.

In addition, the invention heats the cadmium chloride solution, reduces the adverse effect of cadmium chloride spraying on the temperature uniformity of the cadmium telluride sample, thereby effectively preventing the cracking phenomenon of the glass substrate of the sample caused by uneven heating, and the subsequent annealing treatment fully reduces the defects and the compounding in the cadmium telluride film material, improves the efficiency of the cadmium telluride film assembly, reduces the treatment cost and the equipment cost, and is beneficial to large-scale popularization and application.

Preferably, the cadmium chloride heat treatment method comprises the steps of preheating a cadmium telluride sample, performing first cadmium chloride thermal spraying, performing first annealing treatment, performing second cadmium chloride thermal spraying and performing second annealing treatment sequentially.

The invention adopts secondary chlorine treatment to promote the full diffusion of selenium in the cadmium telluride layer, and secondary passivation is carried out on defects, thereby remarkably improving the short-circuit current density and improving the battery performance and the power generation efficiency.

Preferably, the cadmium telluride sample is subjected to a first atmospheric plasma cleaning prior to preheating the cadmium telluride sample.

Preferably, the cadmium telluride sample is subjected to a second atmospheric plasma cleaning between the preheating of the cadmium telluride sample and the thermal spraying of cadmium chloride.

Preferably, the temperature at which the cadmium telluride sample is preheated is 50-200 ℃.

Preferably, in the cadmium chloride thermal spraying process, the heating temperature of the cadmium chloride solution is 50-100 ℃.

Preferably, in the cadmium chloride thermal spraying process, the heating temperature of the cadmium telluride sample is 50-200 ℃.

Preferably, the annealing treatment is at a temperature of 300-450 ℃.

Preferably, the cadmium chloride solution adopted by the cadmium chloride heat treatment method has the concentration of 5-30wt% and the spraying flow of 2-4mL/min.

In a second aspect, the invention provides a device system for the cadmium chloride heat treatment method according to the first aspect, comprising a preheating chamber, a thermal spraying chamber and an annealing chamber which are sequentially connected.

The device comprises a preheating chamber, a thermal spraying chamber, an annealing chamber, a sample heating device, a solution heating device and a spraying device, wherein the sample heating device is arranged in the preheating chamber, the thermal spraying chamber and the annealing chamber respectively, and the solution heating device and the spraying device are also arranged in the thermal spraying chamber.

Preferably, the apparatus system comprises a preheating chamber, a first thermal spraying chamber, a first annealing chamber, a second thermal spraying chamber, and a second annealing chamber connected in sequence.

Preferably, a first atmospheric plasma cleaning device is arranged upstream of the preheating chamber.

Preferably, a second atmospheric plasma cleaning device is arranged between the preheating chamber and the thermal spraying chamber.

Compared with the prior art, the invention has the following beneficial effects:

(1) According to the cadmium chloride heat treatment method provided by the invention, the cadmium telluride sample and the cadmium chloride solution are heated respectively before spraying, so that atomized cadmium chloride droplets are subjected to high temperature when migrating to the surface of the cadmium telluride sample, the solvent is gasified, and finally the dispersed cadmium chloride particles are mainly refined on the surface of the cadmium telluride sample, and the tiny solid particles are directly adsorbed on the surface of the cadmium telluride film to form a film, so that crystallization and agglomeration effects of the droplets are avoided, the formation of dispersed large particles is prevented, and the sample high temperature is also beneficial to the transverse migration of small particles in the initial nucleation process of the film formation, and the continuity and microscopic uniformity of the cadmium chloride film layer are remarkably improved.

(2) According to the invention, the cadmium chloride solution is heated, so that adverse effects of cadmium chloride spraying on the temperature uniformity of a cadmium telluride sample are reduced, the cracking phenomenon of a glass substrate of the sample caused by uneven heating is effectively prevented, defects and compounding in a cadmium telluride film material are fully reduced in subsequent annealing treatment, the efficiency of the cadmium telluride film assembly is improved, and meanwhile, the treatment cost and the equipment cost are reduced, so that the method is beneficial to large-scale popularization and application.

Drawings

FIG. 1 is a schematic view of the apparatus system for cadmium chloride heat treatment provided in example 1;

FIG. 2 is a schematic view of the apparatus system for cadmium chloride heat treatment provided in example 2;

FIG. 3 is a schematic view of the system configuration of the apparatus for cadmium chloride heat treatment provided in comparative example 1;

FIG. 4 is a schematic diagram of a cadmium telluride cell made by the cadmium chloride heat treatment method provided by the invention.

Wherein 10-preheating chamber, 20-thermal spraying chamber, 21-first thermal spraying chamber, 22-second thermal spraying chamber, 30-annealing chamber, 31-first annealing chamber, 32-second annealing chamber, 40-sample heating device, 50-solution heating device, 60-spraying device, 71-first atmosphere plasma cleaning device, 72-second atmosphere plasma cleaning device, 80-cadmium telluride sample, 90-conveyer belt, 101-glass substrate, 102-transparent conductive oxide layer, 103-window layer, 104-absorption layer, 105-back contact layer, 106-back electrode layer.

Detailed Description

The technical scheme of the invention is further described by the following specific embodiments. It will be apparent to those skilled in the art that the examples are merely to aid in understanding the invention and are not to be construed as a specific limitation thereof.

An embodiment of the invention provides a cadmium chloride heat treatment method of a cadmium telluride battery, which comprises the steps of preheating a cadmium telluride sample, thermally spraying and annealing the cadmium chloride sample sequentially.

The cadmium chloride thermal spraying and annealing treatment are respectively carried out at least 1 time, for example, 1 time, 2 times, 3 times, 4 times or 5 times, but the cadmium chloride thermal spraying and annealing treatment are not limited to the listed values, and other non-listed values in the range of the values are applicable.

According to the cadmium chloride heat treatment method provided by the invention, the cadmium telluride sample and the cadmium chloride solution are heated respectively before spraying, so that atomized cadmium chloride droplets are subjected to high temperature when migrating to the surface of the cadmium telluride sample, a solvent (such as water or ethanol) is gasified, and finally the mainly refined and dispersed cadmium chloride particles on the surface of the cadmium telluride sample are finally reached, and the tiny solid particles are directly adsorbed on the surface of the cadmium telluride film to form a film, so that crystallization and agglomeration effects of the droplets are avoided, and the formation of dispersed large particles is prevented, and the sample high temperature is also beneficial to transverse migration of small particles (reaction precursors) in the initial nucleation process of the film formation, and the continuity and microscopic uniformity of the cadmium chloride film layer are remarkably improved.

In addition, the invention heats the cadmium chloride solution, reduces the adverse effect of cadmium chloride spraying on the temperature uniformity of the cadmium telluride sample, thereby effectively preventing the cracking phenomenon of the glass substrate of the sample caused by uneven heating, and the subsequent annealing treatment fully reduces the defects and the compounding in the cadmium telluride film material, improves the efficiency of the cadmium telluride film assembly, reduces the treatment cost and the equipment cost, and is beneficial to large-scale popularization and application.

In certain embodiments, the cadmium chloride heat treatment method includes sequentially performing a cadmium telluride sample pre-heating, a first cadmium chloride thermal spray, a first annealing treatment, a second cadmium chloride thermal spray, and a second annealing treatment.

The invention adopts secondary chlorine treatment to promote the full diffusion of selenium in the cadmium telluride layer, and secondary passivation is carried out on defects, thereby remarkably improving the short-circuit current density and improving the battery performance and the power generation efficiency.

In certain embodiments, the cadmium telluride sample is subjected to a first atmospheric plasma rinse prior to preheating the cadmium telluride sample.

In certain embodiments, the cadmium telluride sample is subjected to a second atmospheric plasma rinse between preheating the cadmium telluride sample and cadmium chloride thermal spraying.

According to the invention, the cadmium telluride sample is subjected to plasma surface treatment through atmospheric plasma cleaning, so that the surface modification is realized, and the wettability of sprayed cadmium chloride droplets on the surface of the cadmium telluride film is fully improved.

In certain embodiments, the temperature at which the cadmium telluride sample is preheated is 50-200 ℃, such as 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, or 200 ℃, although not limited to the recited values, other non-recited values within the range of values are equally applicable.

In certain embodiments, the heating temperature of the cadmium chloride solution during the cadmium chloride thermal spraying process is 50-100 ℃, such as 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃,80 ℃, 85 ℃,90 ℃, 95 ℃, or 100 ℃, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

In certain embodiments, the cadmium telluride sample is heated to a temperature of 50-200 ℃, such as 50 ℃, 60 ℃, 70 ℃, 80 ℃, 90 ℃, 100 ℃, 110 ℃, 120 ℃, 130 ℃, 140 ℃, 150 ℃, 160 ℃, 170 ℃, 180 ℃, 190 ℃, or 200 ℃, but is not limited to the recited values, as are other non-recited values within the range of values.

In certain embodiments, the annealing process is at a temperature of 300-450 ℃, such as 300 ℃, 310 ℃, 320 ℃, 330 ℃, 340 ℃, 350 ℃, 360 ℃, 370 ℃, 380 ℃, 390 ℃, 400 ℃, 410 ℃, 420 ℃, 430 ℃, 440 ℃, or 450 ℃, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

In certain embodiments, the cadmium chloride heat treatment method employs a cadmium chloride solution concentration of 5-30wt%, such as 5wt%, 6wt%, 8wt%, 10wt%, 12wt%, 14wt%, 16wt%, 18wt%, 20wt%, 22wt%, 24wt%, 26wt%, 28wt%, or 30wt%, and the spray flow is 2-4mL/min, such as 2mL/min, 2.2mL/min, 2.4mL/min, 2.6mL/min, 2.8mL/min, 3mL/min, 3.2mL/min, 3.4mL/min, 3.6mL/min, 3.8mL/min, or 4mL/min, but is not limited to the recited values, and other non-recited values within the range of values are equally applicable.

An embodiment of the invention provides a device system adopted by the cadmium chloride heat treatment method, which comprises a preheating chamber, a thermal spraying chamber and an annealing chamber which are connected in sequence.

The device comprises a preheating chamber, a thermal spraying chamber, an annealing chamber, a sample heating device, a solution heating device and a spraying device, wherein the sample heating device is arranged in the preheating chamber, the thermal spraying chamber and the annealing chamber respectively, and the solution heating device and the spraying device are also arranged in the thermal spraying chamber.

In the present invention, the sample heating device and the solution heating device may be heating wires, heating lamps, or the like, respectively, so long as the heating function can be achieved, and the specific structure of each heating device is not particularly limited herein.

In the present invention, the preheating chamber, the thermal spraying chamber and the annealing chamber may be sequentially connected through the high temperature resistant transfer device as long as a transfer function can be achieved, so the specific structure of the high temperature resistant transfer device is not particularly limited herein.

In certain embodiments, the apparatus system includes a preheating chamber, a first thermal spray chamber, a first annealing chamber, a second thermal spray chamber, and a second annealing chamber connected in sequence.

In the invention, the spraying solution and the heating temperature adopted by the first thermal spraying chamber and the second thermal spraying chamber can be the same or different, the heating temperature and the heating time of the first annealing chamber and the second annealing chamber can be the same or different, and the heating temperature and the heating time can be specifically adjusted according to experimental requirements, so that the diffusion of selenium in the selenium-doped multilayer cadmium telluride battery absorption layer is further promoted.

Illustratively, the first thermal spray chamber employs a cadmium chloride solution having a concentration of 5wt%, the second thermal spray chamber employs a cadmium chloride solution having a concentration of 5wt% or a cadmium chloride solution having a concentration of 10wt%, the sample temperature in the first thermal spray chamber is 100 ℃, and the sample temperature in the second thermal spray chamber is 150 ℃.

In certain embodiments, a first atmospheric plasma cleaning device is disposed upstream of the preheating chamber.

In certain embodiments, a second atmospheric plasma cleaning device is disposed between the preheat chamber and the thermal spray chamber.

The numerical ranges recited herein include not only the recited point values, but also any point values between the recited numerical ranges that are not recited, and are limited to, and for the sake of brevity, the invention is not intended to be exhaustive of the specific point values that the recited range includes.

Example 1

This embodiment provides an apparatus system for cadmium chloride heat treatment, as shown in fig. 1, comprising a preheating chamber 10, a thermal spraying chamber 20, and an annealing chamber 30, which are sequentially connected by a conveyor 90.

The preheating chamber 10, the thermal spraying chamber 20 and the annealing chamber 30 are respectively provided with a sample heating device 40, and the thermal spraying chamber 20 is also provided with a solution heating device 50 and a spraying device 60. A first atmospheric plasma cleaning device 71 is arranged upstream of the preheating chamber 10, and a second atmospheric plasma cleaning device 72 is arranged between the preheating chamber 10 and the thermal spraying chamber 20.

In this embodiment, the cadmium telluride sample 80 passes sequentially through the first atmospheric plasma cleaning device 71, the preheating chamber 10, the second atmospheric plasma cleaning device 72, the thermal spray chamber 20, and the annealing chamber 30 by means of the conveyor 90.

Example 2

The present embodiment provides an apparatus system for cadmium chloride heat treatment, as shown in fig. 2, which includes a preheating chamber 10, a first thermal spraying chamber 21, a first annealing chamber 31, a second thermal spraying chamber 22, and a second annealing chamber 32, which are sequentially connected by a conveyor 90.

The preheating chamber 10, the first thermal spraying chamber 21, the first annealing chamber 31, the second thermal spraying chamber 22 and the second annealing chamber 32 are respectively provided with a sample heating device 40, and the first thermal spraying chamber 21 and the second thermal spraying chamber 22 are respectively provided with a solution heating device 50 and a spraying device 60. A first atmospheric plasma cleaning device 71 is provided upstream of the preheating chamber 10, and a second atmospheric plasma cleaning device 72 is provided between the preheating chamber 10 and the first thermal spraying chamber 21.

In the present embodiment, the cadmium telluride sample 80 passes through the first atmospheric plasma cleaning device 71, the preheating chamber 10, the second atmospheric plasma cleaning device 72, the first thermal spraying chamber 21, the first annealing chamber 31, the second thermal spraying chamber 22, and the second annealing chamber 32 in this order by means of the conveyor 90.

Comparative example 1

This comparative example provides an apparatus system for cadmium chloride heat treatment, as shown in fig. 3, comprising a thermal spray chamber 20 and an annealing chamber 30 connected in sequence by a conveyor 90.

Wherein, the thermal spraying chamber 20 is internally provided with a spraying device 60, and the annealing chamber 30 is internally provided with a sample heating device 40.

In this comparative example, a cadmium telluride sample 80 passes sequentially through the thermal spray chamber 20 and the annealing chamber 30 by means of a conveyor 90.

Application example 1

The application example adopts the device system provided in the embodiment 1 to carry out the cadmium chloride heat treatment of the cadmium telluride battery, and comprises the steps of sequentially carrying out first atmospheric plasma cleaning, cadmium telluride sample preheating, second atmospheric plasma cleaning, cadmium chloride thermal spraying and annealing treatment.

The method comprises the steps of preheating a cadmium telluride sample at 50 ℃, heating a cadmium chloride solution and the cadmium telluride sample respectively in the cadmium chloride thermal spraying process, wherein the heating temperature of the cadmium chloride solution is 50 ℃, the heating temperature of the cadmium telluride sample is 50 ℃, the concentration of the cadmium chloride solution is 5wt%, the spraying flow is 2mL/min, and the annealing treatment temperature is 300 ℃.

Application example 2

The application example adopts the device system provided in the embodiment 1 to carry out the cadmium chloride heat treatment of the cadmium telluride battery, and comprises the steps of sequentially carrying out first atmospheric plasma cleaning, cadmium telluride sample preheating, second atmospheric plasma cleaning, cadmium chloride thermal spraying and annealing treatment.

The method comprises the steps of preheating a cadmium telluride sample at 150 ℃, heating a cadmium chloride solution and the cadmium telluride sample respectively in the cadmium chloride thermal spraying process, wherein the heating temperature of the cadmium chloride solution is 80 ℃, the heating temperature of the cadmium telluride sample is 150 ℃, the concentration of the cadmium chloride solution is 20wt%, the spraying flow is 3mL/min, and the annealing treatment temperature is 350 ℃.

Application example 3

The application example adopts the device system provided in the embodiment 1 to carry out the cadmium chloride heat treatment of the cadmium telluride battery, and comprises the steps of sequentially carrying out first atmospheric plasma cleaning, cadmium telluride sample preheating, second atmospheric plasma cleaning, cadmium chloride thermal spraying and annealing treatment.

The method comprises the steps of preheating a cadmium telluride sample at 200 ℃, heating a cadmium chloride solution and the cadmium telluride sample respectively in the cadmium chloride thermal spraying process, wherein the heating temperature of the cadmium chloride solution is 90 ℃, the heating temperature of the cadmium telluride sample is 200 ℃, the concentration of the cadmium chloride solution is 30wt%, the spraying flow is 4mL/min, and the annealing treatment temperature is 450 ℃.

Application example 4

The application example adopts the device system provided in the embodiment 2 to carry out the cadmium chloride heat treatment of the cadmium telluride battery, and comprises the steps of sequentially carrying out first atmospheric plasma cleaning, cadmium telluride sample preheating, second atmospheric plasma cleaning, first cadmium chloride hot spraying, first annealing treatment, second cadmium chloride hot spraying and second annealing treatment.

The method comprises the steps of preheating a cadmium telluride sample at 150 ℃, heating a cadmium chloride solution and the cadmium telluride sample respectively in the first cadmium chloride thermal spraying process and the second cadmium chloride thermal spraying process, wherein the heating temperature of the cadmium chloride solution is 80 ℃, the heating temperature of the cadmium telluride sample is 150 ℃, the concentration of the cadmium chloride solution is 20wt%, the spraying flow is 3mL/min, and the temperature of the first annealing treatment and the second annealing treatment is 350 ℃.

Application example 5

The application example adopts the device system provided in the embodiment 2 to carry out the cadmium chloride heat treatment of the cadmium telluride battery, and comprises the steps of sequentially carrying out first atmospheric plasma cleaning, cadmium telluride sample preheating, second atmospheric plasma cleaning, first cadmium chloride hot spraying, first annealing treatment, second cadmium chloride hot spraying and second annealing treatment.

The method comprises the steps of preheating a cadmium telluride sample at 150 ℃, heating a cadmium chloride solution and the cadmium telluride sample in the first cadmium chloride thermal spraying process and the second cadmium chloride thermal spraying process respectively, wherein the heating temperature of the cadmium chloride solution adopted by the first cadmium chloride thermal spraying process is 50 ℃, the heating temperature of the cadmium telluride sample is 150 ℃, the concentration of the cadmium chloride solution is 5wt%, the spraying flow rate is 2mL/min, the heating temperature of the cadmium chloride solution adopted by the second cadmium chloride thermal spraying process is 90 ℃, the heating temperature of the cadmium telluride sample is 150 ℃, the concentration of the cadmium chloride solution is 30wt%, the spraying flow rate is 4mL/min, the temperature of the first annealing treatment is 300 ℃, and the temperature of the second annealing treatment is 450 ℃.

Comparative application example 1

The comparative application example adopts the device system provided in comparative example 1 to carry out cadmium chloride heat treatment of the cadmium telluride battery, and comprises cadmium chloride spraying and annealing treatment which are sequentially carried out.

In the cadmium chloride spraying process, a cadmium telluride sample and a cadmium chloride solution are both at normal temperature, the concentration of the cadmium chloride solution is 20wt%, the spraying flow is 3mL/min, and the annealing treatment temperature is 350 ℃.

Performance testing

Cadmium telluride batteries including a glass substrate 101, a transparent conductive oxide layer 102 (SnO ₂: F), a window layer 103 (CdS), an absorption layer 104 (CdTe: cdSe), a back contact layer 105 (ZnTe: cu) and a back electrode layer 106 (Mo) which were stacked, as shown in FIG. 4, were each prepared by using the cadmium chloride heat treatment methods provided in application examples 1 to 5 and comparative application example 1.

Specifically, the thickness of the glass substrate 101 is 3.2mm, the thickness of the transparent conductive oxide layer 102 is 400nm, the thickness of the window layer 103 is 100nm, the thickness of the absorption layer 104 is 4 mm, the thickness of the back contact layer 105 is 50nm, and the thickness of the back electrode layer 106 is 200nm.

In addition, the glass substrate 101 is ultra-white float glass, the transparent conductive oxide layer 102 is made by sputtering, the window layer 103 and the absorption layer 104 are made by near-space sublimation, and the back contact layer 105 and the back electrode layer 106 are made by sputtering.

Since the specific preparation process of each layer has no obvious influence on the performance of the final product, specific steps and parameter conditions of each process are not repeated here.

The cadmium chloride coverage rate, the large particle number of the cadmium chloride and the cell efficiency of the cadmium telluride cell obtained by the cadmium chloride heat treatment methods provided in application examples 1-5 and comparative application example 1 are shown in the following table 1.

TABLE 1

As shown in Table 1, the comparative application example 1 shows that the CdCl ₂ solution sprayed at normal temperature has the phenomenon of droplet aggregation, which causes uneven distribution of cadmium chloride and lower coverage rate of cadmium chloride, the application examples 1-3 can reduce droplet aggregation by thermal spraying and remarkably improve the coverage rate of cadmium chloride, the application examples 4-5 can further improve the distribution of cadmium chloride by secondary spraying and secondary annealing, and Se diffusion can be promoted by the secondary spraying and secondary annealing, so that the efficiency of the battery is further improved.

Therefore, the cadmium chloride heat treatment method provided by the invention is characterized in that the cadmium telluride sample and the cadmium chloride solution are respectively heated before spraying, so that atomized cadmium chloride droplets are subjected to high temperature effect when migrating to the surface of the cadmium telluride sample, the solvent is gasified, and finally the main refined and dispersed cadmium chloride particles on the surface of the cadmium telluride sample are finally obtained, the tiny solid particles are directly adsorbed on the surface of the cadmium telluride film to form a film, the crystallization and agglomeration effects of the droplets are avoided, the formation of dispersed large particles is prevented, and the sample high temperature is also favorable for the transverse migration of small particles in the initial nucleation process of the film formation, and the continuity and microcosmic uniformity of the cadmium chloride film are obviously improved.

In addition, the invention heats the cadmium chloride solution, reduces the adverse effect of cadmium chloride spraying on the temperature uniformity of the cadmium telluride sample, thereby effectively preventing the cracking phenomenon of the glass substrate of the sample caused by uneven heating, and the subsequent annealing treatment fully reduces the defects and the compounding in the cadmium telluride film material, improves the efficiency of the cadmium telluride film assembly, reduces the treatment cost and the equipment cost, and is beneficial to large-scale popularization and application.

The foregoing is merely illustrative of the present invention, and the present invention is not limited thereto, and it should be apparent to those skilled in the art that any changes or substitutions that fall within the technical scope of the present invention disclosed herein are within the scope of the present invention.