VO2 cadmium telluride composite intelligent power generation glass and preparation method thereof

Abstract

The invention relates to the technical field of power generation glass, and discloses VO2 cadmium telluride composite intelligent power generation glass and a preparation method thereof. The power generation glass comprises a transparent glass substrate; the FTO front electrode layer is deposited on the glass substrate; the VO2 nano dot array is formed on the FTO front electrode layer; the CdSe window layer is deposited on the VO2 nano dot array; the CdTe absorption layer is deposited on the CdSe window layer, and the CdTe absorption layer is etched to form a suede structure; the ZnTe: Ag: Cu back contact layer is deposited on the CdTe absorption layer; the ITO or metal back electrode layer is deposited on the back contact layer; the VO2 cadmium telluride composite intelligent power generation glass is divided into sub-cell units through laser etching. Based on the working principle of a CdTe solar cell and the application of a VO2 material, the technical bottleneck of the photovoltaic glass in the fields of dynamic dimming and high-temperature efficiency maintenance is solved through the intelligent phase change of the VO2 nanodot array and CdTe energy band engineering, and a standardized solution is provided for a next-generation intelligent photovoltaic device.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of power generation glass, in particular to a VO2 cadmium telluride composite intelligent power generation glass and a preparation method thereof. BACKGROUND

[0002] CdTe solar cells play an important role in the field of thin-film solar cells due to their high conversion efficiency and low manufacturing cost. As an ideal choice for building integrated photovoltaics (BIPV), CdTe thin films can be made into power generation glass with a light transmittance of 30% to 60%, replacing traditional curtain walls or windows, and meeting the demand for natural lighting while generating electricity. At the same time, by adjusting the thickness of the CdTe layer or patterning, color or gradient effects can be achieved, which meets the modern architectural aesthetics, but also has certain disadvantages. The transmittance is fixed and cannot intelligently respond to environmental temperature changes. Excessive solar radiation at high temperatures leads to overheating of the indoor environment, increasing the energy consumption of air conditioners, and cannot dynamically balance the demand for power generation and shading according to temperature. The existing technology of electrochromic (such as WO3) requires continuous power supply, and the system is complex and energy-consuming; the thermochromic material (ordinary VO2) can only regulate infrared, and the visible light regulation is insufficient. The continuous film of ordinary VO2 thin film hinders the transmission of carriers, resulting in a decrease of more than 10% in photovoltaic efficiency. SUMMARY

[0003] Therefore, the application provides a VO2 cadmium telluride composite intelligent power generation glass and a preparation method thereof to solve the above problems.

[0004] To solve the above technical problems, the application provides a VO2 cadmium telluride composite intelligent power generation glass, which comprises:

[0005] a transparent glass substrate;

[0006] an FTO front electrode layer deposited on the glass substrate;

[0007] a VO2 nanodot array formed on the FTO front electrode layer, wherein the nanodots of the nanodot array have a diameter of 80±10 nm and a coverage rate of 50%;

[0008] a CdSe window layer deposited on the VO2 nanodot array, having a thickness of 50-200 nm;

[0009] a CdTe absorption layer deposited on the CdSe window layer, having a thickness of 1500-5000 nm, and the CdTe absorption layer is etched to form a rough structure;

[0010] a ZnTe:Ag:Cu back contact layer deposited on the CdTe absorption layer, having a thickness of 5-20 nm;

[0011] an ITO or metal back electrode layer deposited on the back contact layer;

[0012] The VO2 cadmium telluride composite intelligent power generation glass is divided into sub-cell units by laser etching.

[0013] As an optional mode, the VO2 nanodot array is prepared by the following method:

[0014] A single layer of polystyrene nanospheres with a diameter of 70-100 nm is spin-coated on the FTO front electrode layer;

[0015] An amorphous V2O5 layer with a thickness of 10-50 nm is deposited on the polystyrene nanospheres by a magnetron sputtering method, the sputtering power is 100 W, and the Ar / O2 gas flow ratio is 4:1;

[0016] The polystyrene nanospheres are removed by 100W argon plasma etching for 5 minutes to form V2O5 nanodots;

[0017] The V2O5 nanodots are converted into VO2 nanodots by pulse laser annealing with a wavelength of 532 nm, an energy density of 100 mJ / cm 2 , and a pulse width of 10 ns.

[0018] As an optional mode, the CdSe window layer and the CdTe absorption layer are both deposited by a large-area near-space evaporation method.

[0019] As an optional mode, the back contact layer and the metal back electrode layer are both deposited by a magnetron sputtering method.

[0020] In another aspect, the present application also provides a preparation method of the VO2 cadmium telluride composite intelligent power generation glass, comprising the following steps:

[0021] providing a glass substrate;

[0022] depositing an FTO front electrode layer on the glass substrate;

[0023] preparing a VO2 nanodot array on the FTO front electrode layer;

[0024] depositing a CdSe window layer on the VO2 nanodot array;

[0025] depositing a CdTe absorption layer on the CdSe window layer and etching to form a textured structure;

[0026] depositing a back contact layer on the CdTe absorption layer;

[0027] depositing a back electrode layer on the back contact layer;

[0028] dividing the power generation glass into sub-cell units by laser etching.

[0029] As an optional mode, the preparation of the VO2 nanodot array comprises:

[0030] The V2O5 nano dot is formed by a nanosphere lithography template method.

[0031] The pulse laser annealing is converted into a VO2 nano dot.

[0032] The beneficial effects of the present application are: BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 It is a kind of cadmium telluride power generation glass structure schematic diagram provided by the embodiment of the present application.

[0034] Reference signs:

[0035] 1-glass substrate, 2-FTO substrate, 3-VO2 nano dot film layer, 4-CdSe window layer, 5-CdTe absorption layer, 6-back contact layer, 7-back electrode layer. DETAILED DESCRIPTION

[0036] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the embodiments of the present application will be described in detail below with reference to the drawings. However, those skilled in the art can understand that in the embodiments of the present application, many technical details are proposed in order to make the readers better understand the present application. However, even without these technical details and various changes and modifications based on the following embodiments, the technical scheme claimed by the present application can be realized.

[0037] The light transmittance of conventional CdTe power generation glass is fixed (usually > 90%), and excessive solar radiation under high temperature environment (such as summer) will cause indoor overheating, which requires additional air conditioning energy consumption and increases the building electricity burden; battery efficiency decay: the efficiency of CdTe decreases by 0.3-0.5% for every 1℃ increase in temperature. If VO2 is integrated as a continuous thin film into the CdTe battery, it will cause the carrier transport to be blocked, the VO2 insulating state resistivity is high (> 10 3 Ω·cm), which increases the series resistance and causes the fill factor (FF) to decrease; at the same time, the interface recombination is serious, and the direct contact between the metallic state VO2 and CdTe will introduce a Schottky barrier, which reduces the open circuit voltage (VOC).

[0038] VO2 (vanadium dioxide) is a typical thermotropic material, and its unique metal-insulator phase transition (MIT, Metal-Insulator Transition) property makes it the core of intelligent light modulation technology. The following is its light modulation principle:

[0039] VO2 undergoes a first-order phase transition at 68℃ (which can be adjusted by doping), and the phase transition speed can reach picosecond level (10 -12 seconds), which is much faster than that of electrochromic materials (second level).

[0040] 1. Temperature phase transition

[0041] (1) Low-temperature insulating state (monoclinic, M phase):

[0042] High optical transparency, visible light transmittance > 60%;

[0043] Transparent to infrared light (reflectance < 20%).

[0044] (2) High-temperature metallic state (tetragonal, R phase):

[0045] Visible light transmittance drops to 30-40%;

[0046] High infrared reflectance (> 80%), exhibiting "infrared mirror".

[0047] 2. Optical mechanism of dimming

[0048] (1) Low-temperature insulating state (high optical transparency)

[0049] Energy band structure: band gap ~ 0.7 eV, visible light (1.6-3.1 eV) can penetrate, only partially absorbs ultraviolet light.

[0050] Dielectric properties: low dielectric constant, weak light scattering, high transmittance.

[0051] (2) High-temperature metallic state (low optical transparency)

[0052] Plasmonic effect: sudden increase in free electron concentration, forming plasmonic oscillation, reflecting infrared light (λ > 1200 nm).

[0053] Localized surface plasmon resonance (LSPR): VO2 nanoparticles produce scattering in the visible light band (500-700 nm), reducing transmittance.

[0054] 3. Synergistic effect with CdTe power generation glass

[0055] (1) Temperature self-adaptive regulation

[0056] Surface temperature < 68°C: VO2 remains in insulating state, high optical transparency allows CdTe to fully absorb sunlight for power generation.

[0057] Surface temperature ≥ 68°C: VO2 becomes metallic state, reflecting infrared light reduces CdTe temperature rise, inhibits efficiency decay (traditional CdTe high-temperature efficiency reduction of 15%, integrated VO2 < 5%).

[0058] (2) Spectral selectivity

[0059] Reflecting infrared, transmitting visible light: metallic VO2 reflects 85% of infrared light (reducing heat radiation), while allowing part of the visible light (35%) to enter the CdTe layer to maintain power generation.

[0060] According to the above mechanism, if VO2 is integrated into the CdTe battery as a continuous film: the carrier transport will be blocked, the VO2 insulating state resistivity is high (>10 3 Ω·cm), the series resistance is increased, resulting in a decrease in the fill factor (FF); the interface recombination is serious, and the direct contact of the metal state VO2 with the CdTe will introduce a Schottky barrier, reducing the open circuit voltage (VOC). Therefore, the application adopts a VO2 nanodot array, uses discrete nanodots (coverage 50%), retains a TCO direct contact channel, shortens the hole transport path by 30%, and only increases the series resistance by 10% (compared to the traditional structure ↑ 50%); and avoids high-temperature oxidation through VO2 laser annealing (laser wavelength 532nm, 100mJ / cm 2 );

[0061] The technical problem solved by the application is to automatically reduce the light transmittance from 65% to 35% and increase the infrared reflectivity from 20% to 85% at a temperature of ≥ 68℃ by using the insulator-metal phase transition characteristics of the VO2 nanodot array, significantly reducing heat input while maintaining power generation function. The VO2 metal state reflects infrared light, reducing the CdTe temperature rise, making the high-temperature efficiency only decrease by 4.4% (decrease by 15% in the traditional structure), realizing adaptive adjustment of power generation efficiency and light transmittance, and being suitable for BIPV, vehicle-mounted photovoltaic and other scenes.

[0062] As shown in Figure 1 , in one application embodiment, the VO2 cadmium telluride composite intelligent power generation glass comprises:

[0063] a transparent glass substrate 1;

[0064] an FTO front electrode layer deposited on the glass substrate 1;

[0065] a VO2 nanodot array formed on the FTO front electrode layer, the nanodots of the nanodot array having a diameter of 80±10nm and a coverage of 50%;

[0066] a CdSe window layer deposited on the VO2 nanodot array, having a thickness of 50-200nm;

[0067] a CdTe absorption layer deposited on the CdSe window layer, having a thickness of 1500-5000nm, and the CdTe absorption layer is etched to form a textured structure;

[0068] a ZnTe:Ag:Cu back contact layer 6 deposited on the CdTe absorption layer, having a thickness of 5-20nm;

[0069] an ITO or metal back electrode layer 7 deposited on the back contact layer 6;

[0070] The VO2 cadmium telluride composite intelligent power generation glass is divided into sub-cell units by laser etching.

[0071] As an alternative, the VO2 nanodot array is prepared by the following method:

[0072] Spin-coating a single layer of polystyrene nanospheres with a diameter of 70-100 nm on the FTO front electrode layer;

[0073] Depositing an amorphous V2O5 layer with a thickness of 10-50 nm on the polystyrene nanospheres by magnetron sputtering method, with a sputtering power of 100 W and an Ar / O2 gas flow ratio of 4:1;

[0074] Removing the polystyrene nanospheres by 100 W argon plasma etching for 5 minutes to form V2O5 nanodots;

[0075] Converting the V2O5 nanodots into VO2 nanodots by pulsed laser annealing with a wavelength of 532 nm, an energy density of 100 mJ / cm 2 , and a pulse width of 10 ns.

[0076] As an alternative, both the CdSe window layer and the CdTe absorption layer are deposited by large-area near-space evaporation method.

[0077] As an alternative, both the back contact layer 6 and the metal back electrode layer 7 are deposited by magnetron sputtering method.

[0078] In another aspect, the present application also provides a preparation method of VO2 cadmium telluride composite intelligent power generation glass, comprising the following steps:

[0079] Providing a glass substrate 1;

[0080] Depositing an FTO front electrode layer on the glass substrate 1;

[0081] Preparing a VO2 nanodot array on the FTO front electrode layer;

[0082] Depositing a CdSe window layer on the VO2 nanodot array;

[0083] Depositing a CdTe absorption layer on the CdSe window layer and etching to form a textured structure;

[0084] Depositing a back contact layer 6 on the CdTe absorption layer;

[0085] Depositing a back electrode layer 7 on the back contact layer 6;

[0086] Dividing the power generation glass into sub-cell units by laser etching.

[0087] As an alternative, the preparation of the VO2 nanodot array comprises:

[0088] Forming V2O5 nanodots by nanosphere lithography template method;

[0089] Pulsed laser annealing converts to VO2 nanodots.

[0090] Based on the above scheme, the embodiment has the following beneficial effects, which are significantly better than the prior art in the following scenarios:

[0091] Dynamic light transmission adjustment: The light transmittance is automatically adjusted to 35%-65% by the VO2 phase change material, the infrared reflectivity is up to 85% at high temperature, and the building cooling energy consumption is significantly reduced (25-30% energy saving is measured).

[0092] Stable photovoltaic efficiency: The CdTe battery efficiency decay is only 3.2% in high temperature environment (75℃), which is far better than the traditional CdTe 15% decay.

[0093] Spectrum synergistic utilization: VO2 reflects infrared light (λ>1200nm) and CdTe absorbs visible light (350-850nm), which is complementary, and the light energy utilization rate is increased by 18%.

[0094] One material with multiple functions: single piece of glass integrates power generation, light adjustment and heat insulation, which overturns the traditional split design.

[0095] Passive intelligence: No external energy source, temperature triggered self-adjustment, system reliability is very high.

[0096] The embodiment is not only a technical upgrade, but also a benchmark solution for the integration of photovoltaic, building and transportation across fields.

[0097] Table 1, power generation comparison: high temperature environment in summer (35℃ environment temperature, glass surface temperature 75℃)

[0098]

[0099] Table 2, temperature control and energy saving effect comparison: (10m 2 Curtain wall)

[0100]

[0101] In summary, the patent not only iterates the technology, but also redefines the synergy between photovoltaic and building, providing a "power generation-energy saving-aesthetics" three-in-one solution for carbon neutralization

[0102] The embodiments of the present invention have been described in detail above. The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A VO2 cadmium telluride composite smart power generation glass, characterized in that, include: Transparent glass substrate; FTO front electrode layer deposited on the glass substrate; A VO2 nanodot array is formed on the front electrode layer of the FTO, wherein the nanodot diameter is 80±10nm and the coverage is 50%. A CdSe window layer with a thickness of 50–200 nm is deposited on the VO2 nanodot array; A CdTe absorption layer with a thickness of 1500–5000 nm is deposited on the CdSe window layer, and the CdTe absorption layer is etched to form a textured structure. A ZnTe:Ag:Cu back contact layer deposited on the CdTe absorber layer has a thickness of 5–20 nm. An ITO or metal back electrode layer deposited on the back contact layer; The VO2 cadmium telluride composite smart power generation glass is divided into sub-cell units by laser etching.

2. The VO2 cadmium telluride composite smart power generation glass according to claim 1, characterized in that, The VO2 nanodot array was prepared by the following method: A single layer of polystyrene nanospheres with a diameter of 70-100 nm were spin-coated onto the FTO front electrode layer; A 10–50 nm thick amorphous V₂O₅ layer was deposited on the polystyrene nanospheres using magnetron sputtering with a sputtering power of 100 W and an Ar / O₂ gas flow ratio of 4:

1. Polystyrene nanospheres were removed by etching with 100W argon plasma for 5 minutes to form V2O5 nanodots. V2O5 nanodots were converted into VO2 nanodots by pulsed laser annealing with a wavelength of 532 nm, an energy density of 100 mJ / cm2, and a pulse width of 10 ns.

3. The VO2 cadmium telluride composite smart power generation glass according to claim 1, characterized in that, Both the CdSe window layer and the CdTe absorber layer were deposited using a large-area near-space evaporation method.

4. The VO2 cadmium telluride composite smart power generation glass according to claim 1, characterized in that, Both the back contact layer and the metal back electrode layer are deposited using magnetron sputtering.

5. A method for preparing VO2 cadmium telluride composite smart power generation glass, characterized in that, Includes the following steps: Provide glass substrates; An FTO front electrode layer is deposited on the glass substrate; A VO2 nanodot array was fabricated on the FTO front electrode layer; A CdSe window layer was deposited on the VO2 nanodot array; A CdTe absorber layer is deposited on the CdSe window layer and etched to form a textured structure; A back contact layer is deposited on the CdTe absorber layer; A back electrode layer is deposited on the back contact layer; The power-generating glass is divided into sub-cell units by laser etching.

6. The preparation method according to claim 5, characterized in that, The fabrication of the VO2 nanodot array includes: V2O5 nanodots were formed using a nanosphere photolithography template method. Pulsed laser annealing transforms the material into VO2 nanodots.

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