KR102394750B1 - Sunlight Concentrating Device and Photovoltaic Module Containing the Same - Google Patents

Abstract

The present invention relates to a photovoltaic device and a solar cell module including the same. to provide.

Description

A solar concentrating device and a solar cell module including the same

The present invention relates to a photovoltaic device and a solar cell module including the same, and more particularly, by including a single or a plurality of low-refractive layers between quantum dot layers, solar light concentrating that can overcome the theoretical light concentration limit It relates to a device and a solar cell module including the same.

In recent years, solar power generation facilities capable of generating electric power using solar energy have become increasingly common. Building Integrated Photovoltaic (BIPV) technology, which is used as a building envelope finishing material for such photovoltaic power generation facilities such as solar cells, has recently been attracting attention worldwide as a promising new technology in the 21st century. ) was used in the convention center of

In particular, a concentrator photovoltaic cell is a cell that maximizes light conversion efficiency by concentrating sunlight on a small area, and when using a multi-junction solar cell and a tracking device, it can condense sunlight 300 times or more. When light collection is performed by a light collecting device, it can be expected that the absorbance increases as the concentration of quantum dots is increased or the thickness of the quantum dot layer is increased. A phenomenon in which photons are reabsorbed occurs, so there is a theoretical light concentration limit.

Although Korean Patent Laid-Open Publication No. 10-2019-0101065 describes an increase in the efficiency of a solar cell through a multi-junction structure, there is a problem in that the above-mentioned theoretical light concentration limit still cannot be solved. Accordingly, it is necessary to develop a structure capable of overcoming the theoretical light concentration limit even under a low quantum dot concentration and/or a quantum dot layer thickness.

Republic of Korea Patent Publication No. 10-2019-0101065 (published on August 30, 2019)

The present invention has been devised to solve the above problems, and an object of the present invention is to include a single or a plurality of low-refractive layers between the quantum dot layers, thereby overcoming the theoretical light concentration limit of a solar concentrator and To provide a solar cell module including the same.

In order to achieve the above object of the present invention, a solar light collecting device according to a first aspect of the present invention, a low-refractive layer having a first surface and a second surface facing each other; a first quantum dot layer in contact with the first surface of the low refractive index layer; and a second quantum dot layer in contact with the second surface of the low refractive index layer.

A photovoltaic device according to a second aspect of the present invention includes: a low refractive index layer having a first surface and a second surface facing each other; and a laminate in which n unit solar concentrators including a quantum dot layer in contact with the first surface of the low refractive index layer are stacked, and a second quantum dot layer in contact with the second surface of the n-th low refractive index layer. characterized in that

A photovoltaic device according to a third aspect of the present invention includes: a low refractive index layer having a first surface and a second surface facing each other; a first quantum dot layer in contact with the first surface of the low refractive index layer; and a laminate in which n unit light collecting devices including a second quantum dot layer in contact with the second surface of the low refractive layer are stacked, wherein an air layer is formed between the n unit light collecting devices constituting the stack. characterized by being

A solar cell module according to a fourth aspect of the present invention, comprising a plurality of solar cells electrically connected and disposed in a form surrounding the side surface of the photovoltaic device according to any one of the first to third aspects do it with

According to the present invention, by including a single or a plurality of low-refractive layers between the quantum dot layer, it provides an effect that can overcome the theoretical light concentration limit.

1 to 3 are views showing the structure of a solar concentrator according to an embodiment of the present invention.
4 is a view showing the shape of a hollow silica particle according to an embodiment of the present invention.
5 is a view showing an operating state of the solar concentrator according to an embodiment of the present invention.
6 is a view showing a photon movement path according to an embodiment of the present invention.

Hereinafter, the present invention will be described in detail with reference to examples and drawings. However, the following description is not intended to limit the present invention to specific embodiments, and when it is determined that a detailed description of a related known technology may obscure the gist of the present invention in describing the present invention, the detailed description will be omitted. .

The terminology used herein is used only to describe specific embodiments, and is not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise.

In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, element, or combination thereof described in the specification exists, and includes one or more other features or It should be understood that the possibility of the presence or addition of numbers, steps, acts, elements, or combinations thereof is not precluded in advance.

1 shows a structure and an operating state of a photovoltaic device 100 according to a first aspect of the present invention.

The term 'solar concentrator' in the present invention is also referred to as a luminescent solar concentrator or a luminescent solar concentrator. means the device. The light emitting body is a material capable of emitting visible light or infrared light. At this time, the light emitted from the luminous body is totally reflected due to the difference in refractive index between the air and the glass or plastic substrate and is wave guiding along the substrate to move, and the moved light is condensed by a solar cell and converted into electricity. do.

Referring to FIG. 1 , a photovoltaic device 100 according to a first aspect of the present invention includes a low refractive index layer 110 having a first surface and a second surface facing each other; a first quantum dot layer 120 in contact with the first surface of the low refractive index layer 110; and a second quantum dot layer 130 in contact with the second surface of the low refractive index layer. Here, the first quantum dot layer 120 and the second quantum dot layer 130 include the same or different quantum dots, and the refractive index of the low refractive index layer 110 is the refractive index of the first quantum dot layer 120 and The second quantum dot layer 130 has a lower value than a lower value among the refractive indices of the second quantum dot layer 130 .

2 shows a structure and an operating state of a photovoltaic device 100 according to a second aspect of the present invention.

The photovoltaic device 100 according to the second aspect of the present invention includes a low refractive index layer 110 having a first surface and a second surface facing each other; and a stack in which n unit solar concentrators including a quantum dot layer 120 in contact with the first surface of the low refractive index layer 110 are stacked, and the second surface of the n-th low refractive index layer in contact with A second quantum dot layer 130 is included, and the n quantum dot layers 120 and the second quantum dot layer 130 each include the same or different quantum dots, and the maximum value of the refractive index of the n low refractive index layers. is lower than the minimum values of the refractive index of the n quantum dot layers and the refractive index of the second quantum dot layer, and n is an integer of 2 or more. It is more preferable that n is an integer of 2 or more and 10 or less.

3 shows a structure and an operating state of a photovoltaic device 100 according to a third aspect of the present invention.

A photovoltaic device 100 according to a third aspect of the present invention includes: a low refractive index layer having a first surface and a second surface facing each other; a first quantum dot layer in contact with the first surface of the low refractive index layer; and a laminate in which n unit light collecting devices including a second quantum dot layer in contact with the second surface of the low refractive layer are stacked, wherein an air layer is formed between the n unit light collecting devices constituting the stack. and the n first quantum dot layers and the n second quantum dot layers each include the same or different quantum dots, and the refractive index of the low refractive index layers constituting the unit solar concentrator, respectively, is the first quantum dot layer is lower than the lower of the refractive index of the second quantum dot layer and the refractive index of the second quantum dot layer, and n is an integer of 2 or more. It is more preferable that n is an integer of 2 or more and 10 or less.

In the third aspect of the present invention, the term 'air layer' refers to a layer having a refractive index of 1 in which fine air circulates. Due to the low refractive index of the air layer, the same function as the low refractive index layer can be performed.

The inventors of the present invention, when a single or a plurality of low-refractive layers 110 are included between the quantum dot layers 120 and 130 as in the implementation aspect of the present invention, while maintaining the absorbance, the concentration of quantum dots and / Alternatively, the present invention was completed by discovering that the solar concentrator can be configured to be less than or equal to the threshold of the thickness of the quantum dot layer.

Specifically, the term 'low refractive index layer' in the first aspect of the present invention means that the refractive index of the low refractive index layer is lower than the lower value of the refractive index of the first quantum dot layer and the refractive index of the second quantum dot layer. And, in the second aspect of the present invention, the maximum value of the refractive index of the low-refractive layer constituting the unit solar concentrator, respectively, is more than the minimum value of the refractive index of the n quantum dot layers and the refractive index of the second quantum dot layer means low, and in the third aspect of the present invention, the refractive index of the low refractive index layer constituting the unit solar concentrator, respectively, is higher than the lower value of the refractive index of the first quantum dot layer and the refractive index of the second quantum dot layer means low.

In addition, the term "low refractive index layer" may mean having a refractive index of 1.0 to 1.5 at 25 ℃. The refractive index is preferably 1.0 to 1.4, more preferably 1.0 to 1.3, and most preferably 1.0 to 1.2. When the range of refractive index satisfies the above range, total reflection characteristics are improved, and even if the solar concentrator is configured below the threshold value of the quantum dot concentration and/or the quantum dot layer thickness, which indicates the theoretical light concentration limit, the absorbance and efficiency are improved. can keep

In the first to third aspects of the present invention, the low refractive index layer 110 each independently includes at least one selected from the group consisting of hollow silica particles, hollow titanium dioxide particles, and fluorine-based compounds. In particular, the silica particles and/or titanium dioxide particles use a hollow silica particle and/or a hollow titanium dioxide particle in order to form a hollow in order to increase the total reflection property by lowering the refractive index. It is preferable to use hollow silica particles in that scratch resistance can be improved.

The hollow silica particles may be crystalline particles or amorphous particles, preferably monodisperse particles. In terms of shape, it is preferable that the particles are spherical, but amorphous particles can also be used without limitation. 4 shows the hollow silica particle shape according to an embodiment of the present invention taken at different magnifications with a scanning electron microscope (SEM).

In the first to third aspects of the present invention, each of the low refractive layers 110 independently has a thickness of 0.5 μm to 5 mm. The thickness is preferably 1 μm to 1 mm, more preferably 2 μm to 500 μm, and most preferably 5 μm to 50 μm. When the thickness range satisfies the above range, transmittance can be increased not only in the visible light wavelength range but also in the infrared region of a wider wavelength range, and a broadband total reflection effect can be obtained.

In one embodiment of the present invention, the number average particle diameter of the hollow silica particles is 30 nm to 10 μm. The number average particle diameter is preferably 30 nm to 5 μm, more preferably 50 nm to 2 μm, and most preferably 50 nm to 1 μm. If the number average particle size satisfies the above range, The ratio of the hollow part is increased and fine irregularities are formed on the surface to improve the low refractive index, and thus the optimal total reflection efficiency can be achieved.

The first quantum dot layer 120 and the second quantum dot layer 130 in the first aspect of the present invention, the n quantum dot layers 120 and the second quantum dot layer 130 in the second aspect of the present invention ), or in the third aspect of the present invention, the n first quantum dot layer 120 and the n second quantum dot layer 130 include quantum dots 140 that are the same as or different from each other. The term 'quantum dot (QD)' refers to a single material semiconductor or compound semiconductor composed of particles having a size ranging from 1 nanometer to several tens of nanometers. The quantum dots 140 convert light energy of a specific wavelength into light energy of another wavelength.

The quantum dot 140 of the present invention may have a core-shell structure, and each of the core and the shell may be formed of one or more layers. For example, the quantum dots 140 may have a core-core-shell structure or a core-shell-shell structure.

In one embodiment of the present invention, the quantum dots 140 are Cd, Zn, In, Ga, Al, Si, Hg series, ternary or quaternary group II-VI semiconductor compound, III-V semiconductor compound , Group I-III-VI semiconductor compound, Group IV-VI semiconductor compound, Group IV element or compound, Group II-VI, III-V, I-III-VI compound doped with a transition metal, IV- Group VI compound, or a combination thereof, specifically, CdZnS/ZnS, CdS, CdSe, CdSe/ZnS, PbS, PbSe CdTe, ZnS, ZnSe, ZnTe, GaN, GaP, GaAs, GaSb, AlN, AlP , AlAs, AlSb, InP, InAs, InSb, SiC. CuInS ₂ , AgInS ₂ , ZnCuInS and ZnAgInS, and carbon (Carbon) quantum dots, graphene (graphene) quantum dots, perovskite (Perovskite, CH ₃ NH ₃ PbI ₃ ) quantum dots, especially CuInS ₂ /ZnS it is more preferable

In one embodiment of the present invention, an organic dye may be used instead of the quantum dots 140, for example, LUMOGEN RED (perylene dicarboxyimide fluorescent agent emitting red, BASF Corporation, trade name) ), Lumogen Yellow (LUMOGEN YELLOW, perylene dicarboxyimide fluorescent agent emitting yellow, BASF Corporation, trade name), lumogen orange (LUMOGEN ORANGE, perylene dicarboxyimide fluorescent agent emitting orange color, BASF Corporation, trade name), etc. can

In one embodiment of the present invention, the quantum dots 140 are contained in an amount of 1% to 50% by weight based on the total weight of the solar concentrator 100 . The quantum dots 140 are preferably contained in an amount of 3 to 40 wt%, more preferably in an amount of 5 to 30 wt%, and most preferably in an amount of 10 to 30 wt%. When the content of the quantum dots 140 satisfies the above range, light emitting characteristics compared to the content of the quantum dots 140 can be efficiently exhibited, and desired light guiding can be realized. On the other hand, when the quantum dots 140 are contained in excess of the above range, a problem in which emitted photons are reabsorbed may occur.

The first quantum dot layer 120 and the second quantum dot layer 130 in the first aspect of the present invention, the n quantum dot layers 120 and the second quantum dot layer 130 in the second aspect of the present invention ), or in the third aspect of the present invention, the thickness of the n first quantum dot layer 120 and the n second quantum dot layer 130 are each independently 1 μm to 3 cm. The thickness is preferably 3 μm to 1 cm, more preferably 10 μm to 500 μm, and most preferably 15 μm to 300 μm. When the thickness is less than the above range, the quantum dots 140 must exist at a higher density in order to realize a certain level of light guiding. The deterioration (degradation) of the quantum dots 140 by the accelerated luminous efficiency may be reduced. When the thickness exceeds the above range, a problem of lowering the thickness uniformity in the manufacturing process may occur, and economical problems such as increased production cost may occur.

On the other hand, an object of the present invention is to suppress the reabsorption by lowering the concentration of each quantum dot layer of the entire solar light collecting device 100, thereby overcoming the theoretical light concentration limit and increasing the efficiency. In the first to third aspects, the low refractive index layer 110 each independently has a thickness of 1 μm to 300 μm, and at the same time, in the first aspect of the present invention, the first quantum dot layer 120 and the A second quantum dot layer 130, the n quantum dot layer 120 and the second quantum dot layer 130 in the second aspect of the present invention, or the n first quantum dot layer in the third aspect of the present invention (120) and the n second quantum dot layer 130 are each independently configured to have a thickness of 1 μm to 3 cm.

5 is a view showing an operating state of the solar cell module 200 according to the fourth aspect of the present invention, including the solar concentrator 100 according to the first aspect of the present invention. In the fourth aspect of the present invention, the present invention provides a plurality of photovoltaic cells 150 disposed in a shape surrounding the side surface of the photovoltaic concentrator 100 according to the first to third aspects of the present invention and electrically connected thereto. It provides a solar cell module 200 including.

When the photovoltaic device 100 according to an embodiment of the present invention has a rectangular planar shape, it may be disposed in a shape surrounding the four sides of the photovoltaic device 100 . The plurality of solar cells 150 may be electrically connected in parallel or in series. As the solar cell 150 , a silicon (Si)-based or gallium arsenide (GaAs)-based solar cell 150 may be used, but is not limited thereto.

{Example}

Hereinafter, the present invention will be described in detail by way of Examples. However, the following examples are only examples to help the overall understanding of the present invention, and the content of the present invention is not limited to the following examples.

<Test Example 1> Quantum dot efficiency evaluation

A total of 1500 μm thick solar concentrator (Example 1) in which a 500 μm thick low refractive layer is placed between each 500 μm thick quantum dot layer according to the present invention, and a total of 1000 μm without the low refractive index layer Quantum dot efficiency was evaluated using a solar concentrator (Comparative Example 1) consisting of a single-layer thick quantum dot layer. For quantum dots, CuInS ₂ /ZnS was used, and a low refractive layer containing hollow silica particles was used.

Efficiency analysis was performed using Monte-Carlo simulation, and the results are shown in Table 1 below (unit: %).

division
(unit: %) light absorption light up light down reflect penetration matting in the floor quenching in quantum dots Comparative Example 1 34.7 23.3 22.1 3.9 4.5 0 11.5 Example 1 39.1 21.0 20.1 3.8 4.4 0 11.6

<Glossary>

Light absorption: A phenomenon in which light is transmitted to the side surface of the solar concentrator and transmitted to the solar cell (for example, 39.1% of light absorption in Example 1 is 39.1% on average when 100 solar photons are incident on the upper quantum dot layer means that two photons are transmitted to the solar cell),

upward emission: the phenomenon in which light escapes through the top surface of the solar concentrator;

Downward emission: the phenomenon in which light escapes through the underside of the solar concentrator;

Reflection: A phenomenon in which light is reflected at the interface of the solar concentrator and is not transmitted to the quantum dots;

Transmission: a phenomenon in which light is not absorbed by quantum dots;

Intra-layer quenching: the phenomenon in which light is quenched by a layer within the solar concentrator;

Extinction in Quantum Dots: A phenomenon in which quantum dots do not emit light.

As can be seen in Table 1, when using the photovoltaic device (Example 1) in which the low refractive index layer is positioned between the quantum dot layers, the solar light collecting device consisting of a single quantum dot layer not including the low refractive index layer ( Compared to Comparative Example 1), it can be confirmed that a remarkably improved light absorption efficiency of 4.4%, that is, total reflection efficiency can be achieved.

<Test Example 2> Photon movement path confirmation

With respect to the solar concentrator of Example 1 according to the present invention, a photon movement path was confirmed using a Monte-Carlo simulator. The results are shown in FIG. 6 (unit: μm).

6, x, y, and z indicate the movement path of photons randomly incident on the solar concentrator having a total size of 5 cm x 5 cm x 1.5 mm in μm. When a photon moves to another layer, it is indicated by a different color.

Although the present invention has been described with reference to the above-mentioned preferred embodiments, various modifications and variations are possible without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover such modifications and variations as fall within the scope of the present invention.

100: solar light concentrator 110: low refractive layer
120: first quantum dot layer 130: second quantum dot layer
140: quantum dot 150: solar cell
200: solar cell module

Claims (16)

In the solar concentrating device,
a low refractive index layer having first and second surfaces opposite to each other;
a first quantum dot layer in contact with the first surface of the low refractive index layer; and
A second quantum dot layer in contact with the second surface of the low refractive index layer,
The first quantum dot layer and the second quantum dot layer include the same or different quantum dots,
The refractive index of the low refractive index layer is lower than the lower value of the refractive index of the first quantum dot layer and the refractive index of the second quantum dot layer.
solar concentrator. In the solar concentrating device,
a low refractive index layer having first and second surfaces opposite to each other; and
A laminate in which n unit solar concentrators including a quantum dot layer in contact with the first surface of the low refractive layer are stacked;
A second quantum dot layer in contact with the second surface of the n-th low refractive index layer,
The n quantum dot layers and the second quantum dot layer each include the same or different quantum dots,
The maximum value of the refractive index of the n low refractive index layer is lower than the minimum value of the refractive index of the n quantum dot layer and the refractive index of the second quantum dot layer,
Wherein n is an integer of 2 or more
solar concentrator. In the solar concentrating device,
a low refractive index layer having first and second surfaces opposite to each other;
a first quantum dot layer in contact with the first surface of the low refractive index layer; and
Including a laminate in which n units of a light collecting unit including a second quantum dot layer in contact with the second surface of the low refractive layer are stacked,
An air layer is formed between the n unit light collecting devices constituting the laminate,
The n first quantum dot layers and the n second quantum dot layers each include the same or different quantum dots,
The refractive index of the low refractive index layer is lower than the lower value of the refractive index of the first quantum dot layer and the refractive index of the second quantum dot layer,
Wherein n is an integer of 2 or more
solar concentrator. 4. The method of claim 2 or 3,
Wherein n is an integer of 2 or more and 10 or less, the solar concentrator. The method of claim 1,
The low refractive layer has a refractive index of 1.0 to 1.5 at 25 ℃, solar light collecting device. 4. The method of claim 2 or 3,
The low-refractive layer each independently has a refractive index of 1.0 to 1.5 at 25 ℃, a solar concentrator. The method of claim 1,
The low-refractive layer includes at least one selected from the group consisting of hollow silica particles, hollow titanium dioxide particles, and fluorine-based compounds. 4. The method of claim 2 or 3,
The low-refractive layer each independently comprises at least one selected from the group consisting of hollow silica particles, hollow titanium dioxide particles, and fluorine-based compounds, solar concentrating device. The method of claim 1,
The low-refractive layer has a thickness of 0.5 μm to 5 mm, solar concentrating device. 4. The method of claim 2 or 3,
The low refractive index layer each independently has a thickness of 0.5 μm to 5 mm, a solar light collecting device. 4. The method according to any one of claims 1 to 3,
The quantum dots are each independently CdZnS/ZnS, CdS, CdSe, CdSe/ZnS, PbS, CdTe, ZnS, ZnSe, ZnTe, GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InP, InAs, InSb and At least one selected from the group consisting of SiC, a solar concentrator. 4. The method according to any one of claims 1 to 3,
The total amount of quantum dots included in the photovoltaic device is contained in an amount of 1% to 50% by weight based on the total weight of the photovoltaic device. The method of claim 1,
The first quantum dot layer and the second quantum dot layer each independently have a thickness of 1 μm to 3 cm, a solar light collecting device. 3. The method of claim 2,
The n quantum dot layers and the second quantum dot layer each independently have a thickness of 1 μm to 3 cm, a solar concentrator. 4. The method of claim 3,
The n first quantum dot layers and the n second quantum dot layers each independently have a thickness of 1 μm to 3 cm, a solar concentrator. The solar cell module of any one of claims 1 to 3, comprising a plurality of solar cells electrically connected and disposed in a form surrounding the side surface of the photovoltaic device of any one of claims 1 to 3.

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