Anti-reflection and anti-reflection film on surface of photovoltaic packaging glass and preparation method
Technical Field
The invention relates to the technical field of solar cell packaging, in particular to an antireflection film on the surface of photovoltaic packaging glass and a preparation method thereof.
Background
The common photovoltaic packaging glass of the solar cell has a strong reflection effect on sunlight, so that the light reflection loss is close to 10%, the utilization of light energy is reduced, the power generation efficiency is influenced, and the photoelectric conversion efficiency of the photovoltaic module is greatly reduced. In addition, the use of common photovoltaic packaging glass affects the matching between solar cells thereof, and thus the performance of the overall assembly. Therefore, in order to reduce light loss and improve photoelectric conversion efficiency, it is necessary to plate an antireflection film on the surface of the package glass to improve performance.
In the prior art, the photovoltaic packaging glass material is coated with an anti-reflection and anti-reflection film of silicon dioxide, titanium dioxide, aluminum oxide and other materials on the surface thereof by a sol-gel method, a vacuum electron beam evaporation method, a magnetron sputtering method and other methods, so as to improve the photoelectric conversion efficiency. However, these methods are difficult to control the thickness and shape of the film very precisely, and thus, too thick films are produced, which results in reduced toughness, poor adhesion, and easy occurrence of defects such as cracks and flaking, which results in failure of film performance, and increased cost. In addition, these methods fail to achieve uniformity and conformality for complex shaped photovoltaic encapsulation glass material substrates.
Therefore, the preparation of the universal high-performance anti-reflection and anti-reflection film is particularly critical to the improvement of the photoelectric conversion efficiency of the solar cell and the optimization of the component performance.
Disclosure of Invention
The invention aims to provide an antireflection film on the surface of photovoltaic packaging glass and a preparation method thereof, wherein the film has excellent antireflection effect, high stability, uniformity and durability, and effectively reduces light loss, thereby improving photoelectric conversion efficiency.
In order to achieve the above purpose, the invention provides a preparation method of an antireflection film on the surface of photovoltaic packaging glass, which comprises the following steps:
S1, pre-cleaning the surface of a glass substrate;
s2, adopting a plasma generating device to sweep the surface of the glass substrate;
S3, depositing an ALD-TiO 2 seed layer on the surface of the glass substrate by adopting an atomic layer deposition technology;
S4, depositing an ALD-TiO 2/SiO2 composite layer on the upper surface of the ALD-TiO 2 seed layer according to a certain thickness proportion.
Preferably, S1 is specifically:
and cleaning the surface of the glass substrate by using deionized water to remove impurities, soaking and cleaning the glass substrate by using an organic solvent, and drying after cleaning.
Preferably, S2 is specifically:
And placing the glass substrate into an ALD chamber, and sweeping the surface of the glass substrate by adopting oxygen-argon mixed plasma by setting the plasma power of a plasma generating device to be 600W, wherein the action time is 10-20 min.
Preferably, S3 is specifically:
And (3) in the ALD chamber, setting the temperature range to be 90-120 ℃, vacuumizing to be 0-20 Pa, sequentially and alternately introducing a titanium precursor and an oxidant by taking argon as carrier gas, and performing multiple-cycle deposition to obtain the ALD-TiO 2 seed layer.
Preferably, in S3, the set temperature is 100 ℃.
Preferably, in S3, the range of the multiple cyclic deposition is 100 to 1000cycles.
Preferably, S4 is specifically:
S41, introducing a silicon precursor into an ALD chamber by taking argon as a carrier under the condition of plasma oxygen, and performing repeated cyclic deposition to obtain an ALD-SiO 2 layer;
S42, sequentially and alternately introducing a titanium precursor and an oxidant by taking argon as carrier gas, and circularly depositing for multiple times to obtain an ALD-TiO 2 layer;
s43, repeating a plurality of laminated layers to obtain an ALD-TiO 2/SiO2 composite layer by using one ALD-TiO 2 layer which is deposited repeatedly and a plurality of ALD-SiO 2 layers which are deposited repeatedly as a whole.
In order to achieve the purpose, the invention also provides an antireflection film on the surface of the photovoltaic packaging glass.
Preferably, the ALD-TiO 2 seed layer comprises a glass substrate, and an ALD-TiO 2/SiO2 composite layer sequentially arranged on the surface of the glass substrate, wherein the ALD-TiO 2/SiO2 composite layer comprises a plurality of ALD-SiO 2 layers, and ALD-TiO 2 layers are arranged between the ALD-SiO 2 layers.
Preferably, the number of the ALD-SiO 2 layers is three, and the thickness ratio of the ALD-TiO 2 seed layer, the ALD-SiO 2 layer, the ALD-TiO 2 layer, the ALD-SiO 2 layer, the ALD-TiO 2 layer and the ALD-SiO 2 layer is 5-16:30-40:45-54:15-17:35-44:95-103.
Therefore, the anti-reflection film on the surface of the photovoltaic packaging glass and the preparation method have the beneficial effects that:
(1) The invention adopts atomic layer deposition technology (ALD technology), can realize the accurate control of atomic level, avoids the defects of other technologies, and can form a high-uniformity film on a substrate with a complex 3D surface, so that the high-uniformity and compact TiO 2/SiO2 film can be prepared on a glass substrate, the uniformity is critical for realizing ideal anti-reflection and anti-reflection effects, and the nano-level inorganic film has good anti-reflection and anti-reflection effects, and the transmittance can reach 99.5%.
(2) Compared with the thermal evaporation and magnetron sputtering technologies, the ALD technology can provide better substrate adhesion, and the ALD technology is combined with the pretreatment technology of the surface of the glass substrate by optimizing the pretreatment technology of the surface of the glass substrate, namely, the uniform deposition of the ALD thin film on the surface of the glass substrate is further promoted by plasma activation, so that the substrate adhesion is improved, and the method is important for improving the durability and the stability of the thin film.
(3) According to the invention, through optimizing the ALD coating process, the TiO 2 film has high oxygen sensitivity and shows high response to O 2, which indicates that the ALD technology can prepare a high-quality TiO 2/SiO2 laminated film, so that the coating deposition is more uniform and compact, and the anti-reflection and anti-reflection effects are further improved.
(4) The invention effectively avoids the defect caused by overlarge film deposition thickness, and changes the optical constant of the laminated film by changing the thickness of the laminated film, and the reflection, transmission and absorption characteristics of the film are directly affected, according to the microstructure and surface morphology of the film, the reflectivity can reach the maximum value or the minimum value only when the specific interference condition is met, and when the total thickness of the film is 274nm, the reflectivity is below 0.5 percent and reaches the minimum value.
(5) The TiO 2/SiO2 film prepared by the ALD technology has good environmental stability and is important for outdoor application and long-term stability.
The technical scheme of the invention is further described in detail through the drawings and the embodiments.
Drawings
FIG. 1 is a flowchart of an embodiment of a method for preparing an antireflection film on a photovoltaic packaging glass surface;
FIG. 2 is a schematic structural view of a second embodiment of an antireflection film on a surface of a photovoltaic package glass;
FIG. 3 is a graph showing the reflectance versus wavelength for a second embodiment of an anti-reflection film on a photovoltaic encapsulation glass surface according to the present invention;
Fig. 4 is a graph showing a simulated change of the reflectivity and wavelength of an embodiment of an antireflection film on the surface of a photovoltaic packaging glass, wherein (a) is an embodiment two, (b) is an embodiment three, (c) is an embodiment four, (d) is a comparative example one, and (e) is a comparative example two.
Detailed Description
The technical scheme of the invention is further described below through the attached drawings and the embodiments.
Unless defined otherwise, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this invention belongs.
Example 1
As shown in fig. 1, the preparation method of the antireflection film on the surface of the photovoltaic packaging glass comprises the following steps:
s1, pre-cleaning the surface of a glass substrate, namely cleaning the surface of the glass substrate by using deionized water to remove impurities, soaking and cleaning the glass substrate by using an organic solvent, wherein the organic solvent is ethanol or acetone, and drying after cleaning is finished to remove chemical pollutants on the surface.
S2, adopting a plasma generating device to sweep the surface of the glass substrate, namely placing the cleaned and dried glass substrate into an ALD (atomic layer deposition) chamber, further removing impurities on the surface through an Inductive Coupling (ICP) plasma generating device in the ALD chamber, setting the plasma power of the ICP plasma generating device to be 600W, sweeping the surface of the glass substrate through oxygen/argon mixed plasma, and further removing surface pollution particles after the glass substrate is subjected to plasma treatment for 10-20 min, and further improving the film adhesive force.
And S3, depositing an ALD-TiO 2 seed layer on the surface of the glass substrate by adopting an atomic layer deposition technology, wherein the temperature of the ALD chamber is set to be 90-120 ℃ and optimally set to be 100 ℃, and vacuumizing to be 0-20 Pa. Argon is used as carrier gas to alternately introduce a titanium precursor and an oxidant in sequence, and the ALD-TiO 2 seed layer with the thickness of 16nm is obtained by circulating 216cycles deposition. In this example, the titanium precursor is titanium tetrachloride (TiCl 4) and the oxidant is water (H 2 O).
S4, depositing an ALD-TiO 2/SiO2 composite layer with the thickness of 258nm on the upper surface of the ALD-TiO 2 seed layer according to a certain thickness proportion, and obtaining the antireflection film with the thickness of 274 nm. The method comprises the following steps:
The temperature setting range of the ALD chamber is 90-120 ℃, the optimal setting range is 100 ℃, and the ALD chamber is vacuumized to 0-20 Pa.
Introducing a silicon precursor under the condition of plasma oxygen by taking argon as a carrier, and circularly 276-cycle depositing to obtain the ALD-SiO 2 layer with the thickness of 40 nm. In this embodiment, the silicon precursor is bis (diethylamino) silane (BDEAS) and the oxidizer is plasma enhanced oxygen.
Argon is used as carrier gas to alternately introduce a titanium precursor and an oxidant in sequence, and the ALD-TiO 2 layer with the thickness of 54nm is obtained by cyclic 730cycle deposition.
Introducing a silicon precursor under the condition of plasma oxygen by taking argon as a carrier, and circularly depositing 117cycles to obtain the ALD-SiO 2 layer with the thickness of 17 nm.
Argon is used as carrier gas to alternately introduce a titanium precursor and an oxidant in sequence, and the ALD-TiO 2 layer with the thickness of 44nm is obtained by circulation 595cycles deposition.
Introducing a silicon precursor under the condition of plasma oxygen by taking argon as a carrier, and circularly depositing 710cycles to obtain the ALD-SiO 2 layer with the thickness of 103 nm.
Example two
As shown in FIG. 2, the antireflection film with a total thickness of 274nm prepared by the method of the first embodiment comprises a glass substrate, an ALD-TiO 2 seed layer with a thickness of 16nm and an ALD-TiO 2/SiO2 composite layer with a thickness of 258 nm. Specifically, the thickness of the ALD-SiO 2 layer, the ALD-TiO 2 layer, the ALD-SiO 2 layer, the ALD-TiO 2 layer and the ALD-SiO 2 layer are 40nm, 54nm, 17nm, 44nm and 103nm in sequence.
Example III
The difference from the second example is that the antireflection film with a total thickness of 225nm comprises a glass substrate and an ALD-TiO 2 seed layer (68 cycles), an ALD-SiO 2 layer (207 cycles) with a thickness of 5nm, an ALD-TiO 2 layer (608 cycles) with a thickness of 45nm, an ALD-SiO 2 layer (103 cycles) with a thickness of 15nm, an ALD-TiO 2 layer (473 cycles) with a thickness of 35nm, and an ALD-SiO 2 layer (655 cycles) with a thickness of 95 nm.
Example IV
The difference from example two is that the antireflection film with the total thickness of 250nm comprises a glass substrate and an ALD-TiO 2 seed layer (135 cycles), a ALD-SiO 2 layer (241 cycles) with the thickness of 35nm, an ALD-TiO 2 layer (676 cycles) with the thickness of 50nm, an ALD-SiO 2 layer (103 cycles) with the thickness of 15nm, an ALD-TiO 2 layer (541 cycles) with the thickness of 40nm and an ALD-SiO 2 layer (690 cycles) with the thickness of 100nm in sequence.
Comparative example one
The difference from example two is that the total thickness of the antireflection film is 300nm, and the antireflection film comprises a glass substrate and an ALD-TiO 2 seed layer (270 cycles), an ALD-SiO 2 layer (310 cycles) with the thickness of 20nm, an ALD-TiO 2 layer (811 cycles) with the thickness of 45nm, an ALD-SiO 2 layer (138 cycles) with the thickness of 20nm, an ALD-TiO 2 layer (676 cycles) with the thickness of 50nm and an ALD-SiO 2 layer (724 cycles) with the thickness of 105nm in sequence.
Comparative example two
Unlike example two, an antireflective film having a total thickness of 325nm comprises a glass substrate and, in order, an ALD-TiO 2 seed layer (338 cycles), a 50nm ALD-SiO 2 layer (345 cycles), a 60nm ALD-TiO 2 layer (811 cycles), a 25nm ALD-SiO 2 layer (172 cycles), a 55nm ALD-TiO 2 layer (743 cycles), a 110nm ALD-SiO 2 layer (759 cycles) having a thickness of 25 nm.
Test
The glass substrate sample coated with the anti-reflection film obtained in the second embodiment is placed on a micro-spectrophotometer for reflectivity test, three points (Point 1, point2 and Point3 respectively) are selected for measurement during the test, and the test result is shown in fig. 3.
According to analysis, the wavelength is within the range of 450-700 nm, the reflectivity of the glass substrate covered with the ALD-TiO 2/SiO2 laminated layer is below 0.5%, namely, under the condition of single-sided film coating of the glass substrate, the influence of light absorption and scattering is subtracted, and the transmissivity can reach 99.5%, so that the prepared film has extremely high anti-reflection and anti-reflection effects. In addition, the curves fitted by the three points of Point1, point2 and Point3 on the surface of the glass substrate are close to each other, indicating that the ALD-TiO 2/SiO2 stack is uniformly grown on the glass substrate.
The reflectance simulation test was performed by the optical film design software using the formulations in examples two, three, four, one and two, and the simulation results are shown in fig. 4.
According to analysis, the wavelength is within the range of 450-700 nm, the reflectivity of the second embodiment is still below 0.5%, and the reflectivity is basically consistent with the reflectivity test result of the micro-spectrophotometer, so that the authenticity of the reflectivity simulation test of the optical film design software is proved. The reflectance of the third example was 2.6% or less, the reflectance of the fourth example was 1% or less, the reflectance of the first comparative example was 15% or less, and the reflectance of the second comparative example was 45% or less. This is because the refractive indices of TiO 2 and SiO 2 are different, and changing the thickness of the laminated film changes the optical constants (refractive index and extinction coefficient) of the entire film, and the change in optical constants directly affects the reflection, transmission, and absorption characteristics of the film. In addition, the reflectivity of the film is related to the interference effect of the light waves inside the film, and when the light waves are reflected between different medium interfaces, the thickness of the film determines the path length of the light waves propagating inside the film, thereby affecting the interference condition and thus the reflectivity. The relationship between the reflectivity of the film and the wavelength of incident light shows that under the condition of a certain film thickness, according to the microstructure and the surface morphology of the film (for example, when the content of SiO 2 is increased, the surface roughness of the film is increased), the reflectivity changes with the wavelength, and the reflectivity can reach the maximum value or the minimum value only if the specific interference condition is met.
Therefore, the anti-reflection film on the surface of the photovoltaic packaging glass and the preparation method thereof are adopted, the film has excellent anti-reflection and anti-reflection effects, and has high stability, uniformity and durability, so that the loss of light is effectively reduced, and the photoelectric conversion efficiency is further improved.
It should be noted that the above-mentioned embodiments are merely for illustrating the technical solution of the present invention and not for limiting the same, and although the present invention has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solution of the present invention may be modified or substituted by the same, and the modified or substituted technical solution may not deviate from the spirit and scope of the technical solution of the present invention.