Solar paint and method of preparation thereof

Abstract

Disclosed is a solar paint (100) including a top layer (102), a bottom layer (106), and an active layer (104). The top layer (102) includes a transparent conductor made of Indium Tin Oxide (ITO) with horizontal patterns printed using carbon ink. The bottom layer (106) includes an insulating substrate, a bottom electrode, and a hole conductor. The active layer (104) includes n-type polymer p-type material dispersed in a colloidal suspension with surfactants to prevent aggregation. The colloidal suspension is prepared at a critical coagulation concentration (CCC) to ensure long-term stability. A method of preparing the solar paint (100) is also disclosed, including preparing one or more stock solutions, determining the CCC, and preparing the top, bottom, and active layers.

Description

[0001] SOLAR PAINT AND METHOD OF PREPARATION THEREOF

[0002] FIELD OF DISCLOSURE

[0003] The present disclosure relates to solar energy harvesting technologies, and more particularly to a solar paint and method of preparation thereof.

[0004] BACKGROUND

[0005] Solar energy harvesting technologies have gained significant attention in recent years as a sustainable alternative to fossil fuels. The technologies aim to capture and convert sunlight into usable electrical energy, offering a clean and renewable power source. The field encompasses various approaches, including traditional photovoltaic panels, thin-film solar cells, and emerging nanomaterial-based solutions.

[0006] Conventional solar panels, while effective, often face limitations in terms of manufacturing costs, installation complexity, and aesthetic integration with existing structures. Traditional photovoltaic cells typically require rigid, flat surfaces for optimal performance, limiting their application to specific areas such as rooftops or dedicated solar farms. Additionally, the production of the panels often involves energy- intensive processes and potentially harmful materials, raising concerns about their overall environmental impact.

[0007] Recent advancements in nanotechnology and materials science have led to the development of alternative solar energy harvesting methods, such as quantum dotbased solar cells and thin-film technologies. The approaches offer potential advantages in terms of flexibility, cost-effectiveness, and ease of application. However, challenges remain in achieving long-term stability, maintaining high efficiency, and scaling up production for widespread commercial use. Many existing solutions struggle to balance performance, durability, and manufacturability, often sacrificing one aspect for another. Therefore, there exists a need for a technical solution that solves the aforementioned problems of conventional systems and methods for solar energy harvesting and conversion.

[0008] SUMMARY

[0009] The summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. The summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

[0010] In an aspect of the present disclosure, a solar paint is disclosed. The solar paint includes a top layer comprising a transparent conductor made of Indium Tin Oxide (ITO) with horizontal patterns printed using carbon ink. The solar paint includes a bottom layer comprising an insulating substrate, a bottom electrode, and a hole conductor. The solar paint includes an active layer comprising n and p type semiconductors. The n and p type semiconductors are dispersed in a colloidal suspension with surfactants to prevent aggregation. The colloidal suspension is prepared at a critical coagulation concentration (CCC) to ensure long-term stability.

[0011] In some aspects of the present disclosure, the carbon ink comprises graphene quantun dots.

[0012] In some aspects of the present disclosure, the top layer further comprises a coating of silver nanoparticles for enhanced photon trapping.

[0013] In some aspects of the present disclosure, the bottom layer comprises a first sub-layer comprising the insulating substrate made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). The bottom layer comprises a second sub-layer comprising the bottom electrode made of stacked metal nanoparticles and aluminum- coated zinc oxide (ZnO). The bottom layer comprises a third sub-layer comprising the hole conductor made of PEDOT:PSS. In some aspects of the present disclosure, the bottom electrode functions as both a reflector and conductor for electron transport.

[0014] In an aspect of the present disclosure, a method of preparing a solar paint is disclosed. The method includes preparing one or more stock solutions comprising , TiO2, or n and p type semiconductors dispersed in N-N-dimethyl-formamide (DMF) solvent. The method includes determining a critical coagulation concentration (CCC) of each of the one or more stock solutions by diluting each of the one or more stock solutions to multiple concentrations and monitoring stability using UV-Vis-NIR absorption data. The method includes preparing a top layer comprising a transparent conductor made of Indium Tin Oxide (ITO) with horizontal patterns printed using carbon ink. The method includes preparing a bottom layer comprising an insulating substrate, a bottom electrode, and a hole conductor. The method includes preparing an active layer comprising n-type and p-type semiconducting materials dispersed in each of the one or more stock solutions at the determined CCC.

[0015] In some aspects of the present disclosure, determining the critical coagulation concentration (CCC) includes preparing dilutions of each of the one or more stock

[0016] 5 6 7 solutions to concentrations of 5xlO'JM, 5xlO'°M, and 5x10 M where M stands for molarity. Determining the CCC includes bath sonicating each dilution for a predefined period of time at a constant temperature. Determining the CCC includes monitoring stability of each dilution for a predefined time period using UV-Vis-NIR absorption data.

[0017] In some aspects of the present disclosure, preparing the top layer further includes coating the ITO patterns with silver nanoparticles to enhance photon trapping. Preparing the top layer includes annealing the top layer at 120°C on a hot plate.

[0018] In some aspects of the present disclosure, preparing the bottom layer includes forming a first sub-layer comprising the insulating substrate made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). Preparing the bottom layer includes forming a second sub-layer comprising the bottom electrode made of stacked metal nanoparticles and aluminum-coated zinc oxide (ZnO). Preparing the bottom layer includes forming a third sub-layer comprising the hole conductor made of PEDOT:PSS.

[0019] In some aspects of the present disclosure, preparing the active layer further includes mixing n type semiconductors having a direct band gap of 1.5 eV with p type semiconductors having a direct band gap of 0.4 eV at room temperature. Preparing the active layer includes dispersing the mixed n and p type semiconductors in each of the one or more stock solutions at the determined CCC to facilitate multiple exciton generation.

[0020] The foregoing general description of the illustrative aspects and the following detailed description thereof are merely exemplary aspects of the teachings of this disclosure and are not restrictive.

[0021] BRIEF DESCRIPTION OF FIGURES

[0022] The following detailed description of the preferred aspects of the present disclosure will be better understood when read in conjunction with the appended drawings. The present disclosure is illustrated by way of example, and not limited by the accompanying figures, in which like references indicate similar elements.

[0023] FIG. 1 illustrates a cross-sectional view of structure of a solar paint, according to aspects of the present disclosure.

[0024] FIG. 2 illustrates a flowchart of a method for preparing solar paint, according to aspects of the present disclosure.

[0025] DETAILED DESCRIPTION

[0026] The following description sets forth exemplary aspects of the present disclosure. It should be recognized, however, that such description is not intended as a limitation on the scope of the present disclosure. Rather, the description also encompasses combinations and modifications to those exemplary aspects described herein. The present disclosure relates to a solar paint that can convert any surface or structure into a solar panel. A solar paint 100 may comprise multiple layers designed to efficiently capture and convert solar energy into electrical power. The solar paint 100 may include a top layer, a bottom layer, and an active layer sandwiched between the top and bottom layers.

[0027] The solar paint 100 may be applied to various surfaces such as buildings, vehicles, or other structures to harness solar energy. The versatile application method may allow for widespread adoption of solar energy harvesting without the need for traditional bulky solar panels.

[0028] In some aspects of the present disclosure, the solar paint 100 may aim to achieve at least 10% efficiency in converting solar energy to electrical energy. Additionally, the solar paint 100 may be designed to have a lifetime of at least 40,000 hours, ensuring long-term durability and performance.

[0029] The layered structure of the solar paint 100 may enable efficient light absorption, charge generation, and charge collection. The top layer may serve as a transparent conductor, allowing sunlight to pass through while collecting generated electrons. The active layer may contain n and p type semiconductors that absorb light and generate electron-hole pairs. The bottom layer may function as a hole conductor and provide structural support.

[0030] By utilizing advanced materials and fabrication techniques, the solar paint 100 may offer a promising solution for integrating solar energy harvesting capabilities into everyday surfaces and structures. The technology has the potential to revolutionize renewable energy generation by making solar power more accessible and adaptable to various environments.

[0031] FIG. 1 illustrates a cross-sectional view of structure of a solar paint 100. The solar paint 100 may include three main layers: a top layer 102, a bottom layer 106, and an active layer 104. The top layer 102 may be disposed at the uppermost part of the structure of the solar paint 100. In some aspects of the present disclosure, the top layer 102 may comprise a transparent conductor made of Indium Tin Oxide (ITO). The top layer 102 may further include horizontal patterns printed using carbon ink. The transparent nature of the top layer 102 may allow incident light to pass through. The horizontal patterns in the top layer 102 may function as current collectors, facilitating the efficient collection of generated electrons.

[0032] The bottom layer 106 may be positioned at the base of the solar paint 100 structure. In some aspects of the present disclosure, the bottom layer 106 may comprise multiple sub-layers, including an insulating substrate, a bottom electrode, and a hole conductor. The insulating substrate may provide structural support and electrical isolation. The bottom electrode may facilitate charge collection, while the hole conductor may aid in the transport of positive charges (holes) generated in the active layer 104.

[0033] The active layer 104 may be disposed beneath the top layer 102 and the bottom layer 106. In some aspects of the present disclosure, the active layer 104 may comprise n and p type semiconductors. The active layer 104 may be where light absorption and charge generation occur. The n and p type semiconductors in the active layer 104 may be of varying compositions and sizes, that may be represented by the mixture of differentsized particles shown in FIG. 1. The use of n and p type semiconductors may allow for broad spectrum light absorption and efficient charge generation.

[0034] In some aspects of the present disclosure, the n and p type semiconductors may be one of an organic type, inorganic type, or a combination thereof.

[0035] FIG. 1 further illustrates the movement of charges within the solar paint 100. As illustrated in FIG.l, electrons (e-) may be moving towards the top layer 102, while holes (h+) may be moving towards the bottom layer 106. The charge separation may be a fundamental process in the operation of the solar paint 100, converting incident light into electrical energy. The layered structure of the solar paint 100 may allow for efficient light absorption, charge generation, and charge collection. The top layer 102 may permit light to enter within the structure of the solar paint 100 while collecting electrons. The active layer 104 may absorb light and generate electron-hole pairs. The bottom layer 106 may collect holes and provide structural support. The arrangement may enable the solar paint 100 to convert any surface or structure into a solar panel, potentially revolutionizing solar energy harvesting.

[0036] The top layer 102 of the solar paint 100 may comprise multiple components designed to efficiently capture and transmit light while collecting generated electrons. In some aspects of the present disclosure, the top layer 102 may include a transparent conductor made of Indium Tin Oxide (ITO) with horizontal patterns printed using carbon ink. The carbon ink may comprise graphene or multi-walled carbon nanotubes having a conductivity ranging from 103 S / m to 108 S / m. The high conductivity may enable efficient collection and transport of electrons generated in the active layer 104.

[0037] In some aspects of the present disclosure, the top layer 102 may further include a coating of silver nanoparticles. The silver nanoparticle coating may enhance photon trapping within the solar paint 100, potentially increasing the overall light absorption and efficiency of the device. The enhanced photon trapping may allow for a thinner active layer 104 while maintaining high light absorption, potentially reducing material costs and improving flexibility of the solar paint 100.

[0038] The top layer 102 may further include mesoporous TiO2 nanoparticles. The TiO2 nanoparticles may be deposited using an electrophoresis - van der Waals force assisted deposition mechanism. The mesoporous structure of the TiO2 nanoparticles may provide a large surface area for electron transport, potentially improving the efficiency of charge collection in the solar paint 100. Additionally, the TiO2 nanoparticles may function as an electron transport layer, facilitating the movement of electrons from the active layer 106 to the conductive components of the top layer 102. The combination of the ITO transparent conductor, conductive carbon ink patterns, silver nanoparticle coating, and mesoporous TiO2 nanoparticles in the top layer 102 may work synergistically to optimize light transmission, electron collection, and overall performance of the solar paint 100. The multi-component structure may allow for efficient harvesting of solar energy while maintaining the flexibility and versatility required for application on various surfaces.

[0039] Examples of the carbon ink used in the top layer 102 may include, but are not limited to, graphene -based inks, carbon nanotube -based inks, or hybrid inks combining both materials. Aspects of the present disclosure are intended to include and / or otherwise cover any type of conductive carbon ink known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0040] The deposition of the various components of the top layer 102 may be achieved through a combination of techniques. In some aspects of the present disclosure, the ITO may be deposited using sputtering or chemical vapor deposition techniques. The carbon ink patterns may be applied using screen printing, inkjet printing, or other suitable printing methods. The silver nanoparticle coating may be applied using spray coating, spin coating, or electrodeposition. The mesoporous TiO2 nanoparticles may be deposited using the electrophoresis - van der Waals force assisted deposition mechanism, that may allow for precise control over the thickness and uniformity of the layer.

[0041] The top layer 102 may be designed to be both transparent and conductive, allowing sunlight to pass through to the active layer 106 while efficiently collecting and transporting generated electrons. The transparency of the top layer 102 may be optimized to maximize light transmission while maintaining sufficient conductivity for electron collection. In some aspects of the present disclosure, the thickness of the top layer 102 may be carefully controlled to balance the properties.

[0042] The bottom layer 106 of the solar paint 100 may comprise multiple sub-layers, each serving a specific function in the operation of the solar paint 100. In some aspects of the present disclosure, the bottom layer 106 may include three distinct sub-layers: an insulating substrate, a bottom electrode, and a hole conductor.

[0043] The first sub-layer of the bottom layer 106 may be an insulating substrate. In some aspects of the present disclosure, the insulating substrate may be made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). The insulating substrate may provide structural support for the solar paint 100 and may also serve as an electrical insulator, preventing unwanted current flow between other layers or components of the solar paint 100.

[0044] The second sub-layer of the bottom layer 106 may be a bottom electrode. In some aspects of the present disclosure, the bottom electrode may be made of stacked metal nanoparticles and aluminum-coated zinc oxide (ZnO). The bottom electrode may serve as a conductor, facilitating the flow of electrical current generated by the solar paint 100.

[0045] The third sub-layer of the bottom layer 106 may be a hole conductor. In some aspects of the present disclosure, the hole conductor may be made of PEDOT:PSS. The hole conductor may facilitate the transport of positive charges (holes) generated in the active layer 104, contributing to the overall charge separation and current generation in the solar paint 100.

[0046] In some aspects of the present disclosure, the bottom layer 106 may further include carbon nanotubes as part of electrode structure of the bottom layer 106. The carbon nanotubes may enhance the conductivity and structural integrity of the bottom electrode.

[0047] The multi-layered structure of the bottom layer 106 may work in concert to support the function of the solar paint 100. The insulating substrate may provide a stable base and electrical isolation. The bottom electrode may collect charges and reflect light, while the hole conductor may facilitate the movement of positive charges. Together, the components of the bottom layer 106 may contribute to the efficient operation of the solar paint 100, supporting charge separation, current collection, and overall energy conversion efficiency.

[0048] Examples of the insulating substrate may include, but are not limited to, various grades or formulations of PET or PEN, or other suitable insulating materials. Aspects of the present disclosure are intended to include and / or otherwise cover any type of insulating substrate known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0049] Examples of the bottom electrode may include, but are not limited to, various thicknesses or compositions of stacked metal nanoparticles, aluminum-coated zinc oxide, or other suitable conductive and reflective materials. Aspects of the present disclosure are intended to include and / or otherwise cover any type of bottom electrode material known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0050] Examples of the hole conductor may include, but are not limited to, various forms or preparations of PEDOT:PSS, or other suitable hole -transporting materials. Aspects of the present disclosure are intended to include and / or otherwise cover any type of hole conductor known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0051] The active layer 104 of the solar paint 100 may comprise n and p type semiconductors. The n and p type semiconductors may be dispersed in a colloidal suspension with surfactants to prevent aggregation. The colloidal suspension may be prepared at a critical coagulation concentration (CCC) to ensure long-term stability of the active layer 104.

[0052] In some aspects of the present disclosure, the n and p type semiconductors in the active layer 106 may play a crucial role in light absorption and charge generation. The n type semiconductors may have a direct band gap of 1.5 eV at room temperature, while the p type semiconductors may have a direct band gap of 0.4 eV. The combination of the n and p type semiconductors with different band gaps may allow for broad spectrum light absorption, potentially increasing the overall efficiency of the solar paint 100.

[0053] In some aspects of the present disclosure, the n and p type semiconductors may be made up of one of CdTe, PbS, or any combination thereof.

[0054] The use of surfactants in the colloidal suspension may help maintain the stability of the n and p type semiconductors and prevent their aggregation. The use of surfactants may be crucial for maintaining the efficiency and longevity of the solar paint 100. The surfactants may act as protective agents, binding to the nanoparticles and maintaining colloidal stability.

[0055] The preparation of the colloidal suspension at the critical coagulation concentration (CCC) may be a key factor in ensuring the long-term stability of the active layer 104. The CCC may represent the threshold concentration below which the colloidal suspension remains stable and resists coagulation over an extended period. The stability may be essential for the consistent performance of the solar paint 100 over time.

[0056] In some aspects of the present disclosure, the n and p type semiconductors in the active layer 1064 may facilitate multiple exciton generation. The phenomenon may occur as a result of absorbing a broader light spectrum, potentially enhancing the efficiency of the active layer 104 in converting incident photons into electron-hole pairs.

[0057] The composition and structure of the active layer 104 may be designed to optimize light absorption, charge generation, and charge transport within the solar paint 100. By carefully selecting and combining different types of the n and p type semiconductors, and ensuring their stable dispersion through the use of surfactants and precise concentration control, the active layer 106 may contribute significantly to the overall efficiency and performance of the solar paint 100.

[0058] FIG. 2 illustrates a flowchart of a method 200 for preparing the solar paint 100. The method 200 may comprise a series of steps that outline the process of creating a multilayered solar paint structure. The method 200 may begin with a step 202 of preparing one or more stock solutions. In some aspects of the present disclosure, the one or more stock solutions may comprise TiO2, or the n and p type semiconductors dispersed in N-N-dimethyl-formamide (DMF) solvent. The initial step may set the foundation for the subsequent layers of the solar paint.

[0059] The preparation of the one or more stock solutions may involve adding 0.5 mg of nanoparticles to 100 ml of N-N-dimethyl-formamide (DMF) solvent. The nanoparticles may be selected from graphene, or TiO2, , depending on the desired properties of the solar paint. The precise ratio of nanoparticles to solvent may be crucial for achieving the optimal concentration for the subsequent steps in the solar paint preparation process.

[0060] In some aspects of the present disclosure, the preparation of the one or more stock solutions may be carried out separately for each type of nanoparticle. For instance, a stock solution of graphene nanoparticles may be prepared separately from a stock solution of TiO2 nanoparticles. The approach may allow for better control over the composition of the final solar paint.

[0061] The process of preparing the one or more stock solutions may involve several steps. First, the nanoparticles may be carefully weighed to ensure the correct amount of 0.5 mg is used. Next, the N-N-dimethyl-formamide (DMF) solvent may be measured to obtain 100 ml. The nanoparticles may then be added to the solvent in a suitable container.

[0062] To ensure proper dispersion of the nanoparticles in the solvent, the mixture may be subjected to a mixing process. The mixing process may involve using techniques such as sonication or mechanical stirring. The duration and intensity of the mixing process may be carefully controlled to achieve optimal dispersion without damaging the nanoparticles.

[0063] The preparation of the one or more stock solutions may be a critical step in the method 200 for preparing the solar paint. The concentration and dispersion of nanoparticles in the one or more stock solutions may directly influence the properties of the top layer, the bottom layer, and the active layer of the solar paint. Therefore, careful attention to detail and precise measurements may be essential during the step.

[0064] Examples of the solvent used in the preparation of the one or more stock solutions may include, but are not limited to, N-N-dimethyl-formamide (DMF), dimethyl sulfoxide (DMSO), or other suitable organic solvents. Aspects of the present disclosure are intended to include and / or otherwise cover any type of solvent known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0065] The preparation of the one or more stock solutions may set the stage for the subsequent steps in the method 200, including determining the critical coagulation concentration, preparing the top layer, preparing the bottom layer, and preparing the active layer of the solar paint. The quality and consistency of the one or more stock solutions may play a crucial role in the overall performance and efficiency of the resulting solar paint. Further, the method 200 may include a step 204 of determining a critical coagulation concentration (CCC) of each of the one or more stock solutions. The step may be crucial for ensuring the long-term stability of the n and p type semiconductors suspension used in the solar paint.

[0066] In some aspects of the present disclosure, the step 204 of determining the CCC may include preparing dilutions of each of the one or more the stock solutions to concentrations of 5xl0A-5 molar, 5xl0A-6 molar, and 5xlOA-7 molar. The dilutions may be prepared from an initial stock solution of the one or more stock solutions containing the n and p type semiconductors dispersed in N-N-dimethyl-formamide (DMF) solvent.

[0067] The step 204 may further include bath sonicating each dilution for a predefined time period at a constant temperature. Aspects of the present disclosure are intended to include, or otherwise may cover any predefined time period, known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure. In a preferred aspect of the present disclosure, predefined time period may be four hours. Bath sonication may be employed to break down any aggregates and ensure uniform dispersion of the n and p type semiconductors in the solvent. Maintaining a constant temperature during sonication may be important to prevent any temperature -induced changes in the colloidal suspension.

[0068] After sonication, the step 204 may involve monitoring the stability of each dilution weekly for a predefined period of time using UV-Vis-NIR absorption data. Aspects of the present disclosure are intended to include, or otherwise may cover any predefined period of time, known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure. In a preferred aspect of the present disclosure, predefined period of time may be two months. UV-Vis-NIR spectroscopy may be a powerful technique for detecting even small changes in the colloidal suspension. By monitoring the absorption spectra over time, it may be possible to identify any signs of aggregation or instability in the diluted solutions.

[0069] The CCC may be determined as the highest concentration at which the colloidal suspension remains stable over the 2-month monitoring period. The concentration may represent the optimal balance between the n and p type semiconductors’ concentration and long-term stability, which may be crucial for the performance and durability of the solar paint.

[0070] The determination of the CCC may be a critical step in the preparation of the solar paint, as it may ensure that the n and p type semiconductors remain well-dispersed and stable in the final product. The stability may be essential for maintaining the efficiency of the top layer, the bottom layer, and the active layer of the solar paint over time.

[0071] Examples of the UV-Vis-NIR spectroscopy equipment used for stability monitoring may include, but are not limited to, benchtop spectrophotometers, portable spectrophotometers, or fiber optic probe-based systems. Aspects of the present disclosure are intended to include and / or otherwise cover any type of UV-Vis-NIR spectroscopy equipment known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0072] Further, the method 200 may include a step 206 of preparing the top layer of the solar paint. In some aspects of the present disclosure, the step 206 may focus on creating a transparent conductor using Indium Tin Oxide (ITO) and applying horizontal patterns printed using carbon ink. The top layer may serve as the electron-collecting component of the solar paint.

[0073] In some aspects of the present disclosure, the step 206 of preparing the top layer may further include coating the ITO patterns with silver nanoparticles. The silver nanoparticle coating may enhance photon trapping within the solar paint, potentially increasing the overall light absorption and efficiency of the device. The enhanced photon trapping may allow for a thinner active layer while maintaining high light absorption, potentially reducing material costs and improving flexibility of the solar paint.

[0074] The step 206 may further include annealing the top layer at 120°C on a hot plate. Annealing may help improve the conductivity and stability of the ITO and silver nanoparticle coating. The annealing process may also help ensure good adhesion between the different components of the top layer.

[0075] Examples of the carbon ink used in the top layer may include, but are not limited to, graphene -based inks, carbon nanotube -based inks, or hybrid inks combining both materials. Aspects of the present disclosure are intended to include and / or otherwise cover any type of conductive carbon ink known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0076] The deposition of the various components of the top layer may be achieved through a combination of techniques. In some aspects of the present disclosure, the ITO may be deposited using sputtering or chemical vapor deposition techniques. The carbon ink patterns may be applied using screen printing, inkjet printing, or other suitable printing methods. The silver nanoparticle coating may be applied using spray coating, spin coating, or electrodeposition.

[0077] The top layer may be designed to be both transparent and conductive, allowing sunlight to pass through to the active layer while efficiently collecting and transporting generated electrons. The transparency of the top layer may be optimized to maximize light transmission while maintaining sufficient conductivity for electron collection. In some aspects of the present disclosure, the thickness of the top layer may be carefully controlled to balance the properties.

[0078] Further, the method 200 may include a step 208 of preparing the bottom layer of the solar paint. In some aspects of the present disclosure, the step 208 may involve creating multiple sub-layers that together form the bottom layer of the solar paint.

[0079] The first sub-layer of the bottom layer may be an insulating substrate. In some aspects of the present disclosure, the insulating substrate may be made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). The insulating substrate may provide structural support for the solar paint and may also serve as an electrical insulator, preventing unwanted current flow between other layers or components of the solar paint.

[0080] The second sub-layer of the bottom layer may be a bottom electrode. In some aspects of the present disclosure, the bottom electrode may be made of stacked metal nanoparticles and aluminum-coated zinc oxide (ZnO). The bottom electrode may serve a dual function within the solar paint. First, it may act as a conductor, facilitating the flow of electrical current generated by the solar paint. Second, it may function as a reflector, helping to redirect any light that passes through the active layer back into the active layer, potentially increasing the overall light absorption and efficiency of the solar paint.

[0081] The third sub-layer of the bottom layer may be a hole conductor. In some aspects of the present disclosure, the hole conductor may be made of PEDOT:PSS. The hole conductor may facilitate the transport of positive charges (holes) generated in the active layer, contributing to the overall charge separation and current generation in the solar paint.

[0082] In some aspects of the present disclosure, the preparation of the bottom layer may involve specific deposition techniques for each sub-layer. The insulating substrate may be prepared by solution casting or extrusion of the PET or PEN material. The bottom electrode may be deposited using techniques such as sputtering or chemical vapor deposition to create the aluminum-coated ZnO layer. The hole conductor layer may be applied using techniques such as spin coating or spray coating.

[0083] The thickness and uniformity of each sub-layer may be carefully controlled during the preparation process to ensure optimal performance of the bottom layer. In some aspects of the present disclosure, the total thickness of the bottom layer may be in the range of 100-500 nanometers, with each sub-layer having a specific thickness optimized for function of the bottom layer.

[0084] Examples of the insulating substrate may include, but are not limited to, various grades or formulations of PET or PEN, or other suitable insulating polymers. Aspects of the present disclosure are intended to include and / or otherwise cover any type of insulating substrate known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0085] Examples of the bottom electrode may include, but are not limited to, various thicknesses or compositions of stacked metal nanoparticles, aluminum-coated zinc oxide, or other suitable conductive and reflective materials. Aspects of the present disclosure are intended to include and / or otherwise cover any type of bottom electrode material known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0086] Examples of the hole conductor may include, but are not limited to, various forms or preparations of PEDOT:PSS, or other suitable hole -transporting materials. Aspects of the present disclosure are intended to include and / or otherwise cover any type of hole conductor known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0087] The preparation of the bottom layer may be a critical step in the fabrication of the solar paint, as it provides the foundation for the active layer and influences the overall performance of the solar paint. The careful selection and deposition of materials for each sub-layer may contribute to the efficiency, stability, and durability of the solar paint.

[0088] Furthermore, the method 200 may include a step 210 of preparing the active layer of the solar paint. In some aspects of the present disclosure, the step 210 may involve preparing a mixture of n and p type semiconducting materials and dispersing them in each of the one or more stock solutions.

[0089] The step 210 of preparing the active layer may further include mixing n type semiconductors having a direct band gap of 1.5 eV with p type semiconductors having a direct band gap of 0.4 eV at room temperature. The combination of the n and p type semiconductors with different band gaps may allow for broad spectrum light absorption, potentially increasing the overall efficiency of the solar paint 100.

[0090] In some aspects of the present disclosure, the step 210 may further include dispersing the mixed n and p type semiconductors in the one or more stock solutions at the determined critical coagulation concentration (CCC) to facilitate multiple exciton generation. The use of the previously determined CCC may ensure the long-term stability of the n and p type semiconductors suspension in the active layer.

[0091] The dispersion of the mixed n and p type semiconductors at the CCC may be achieved through various techniques. In some aspects of the present disclosure, the dispersion process may involve bath sonication or mechanical stirring to ensure uniform distribution of the n and p type semiconductors in each of the one or more stock solutions. The duration and intensity of the dispersion process may be carefully controlled to achieve optimal dispersion without damaging the n and p type semiconductors. The preparation of the active layer may be a critical step in the fabrication of the solar paint 100, as the active layer may be responsible for light absorption and charge generation. The careful selection and mixing of the n and p type semiconductors, along with their precise dispersion at the CCC, may contribute to the efficiency and stability of the solar paint 100.

[0092] Examples of the n and p type semiconductors used in the active layer may include, but are not limited to, various sizes or compositions of CdTe and PbS, or other suitable light-absorbing nanoparticles. Aspects of the present disclosure are intended to include and / or otherwise cover any type of the n and p type semiconductors material known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0093] The preparation of the active layer may set the stage for the final assembly of the solar paint 100, combining the previously prepared top layer and bottom layer with the active layer to create a complete and functional solar paint structure. The quality and consistency of the active layer may play a crucial role in the overall performance and efficiency of the resulting solar paint 100.

[0094] In some aspects of the present disclosure, alternative methods for depositing the n and p type semiconductors in the solar paint may be employed. While the electrophoresis - van der Waals forces assisted printing mechanism may offer precise control over the deposition process, other techniques may also be utilized depending on specific manufacturing requirements or constraints.

[0095] For example, spin coating may be used as an alternative deposition method. In the technique, a solution containing the n and p type semiconductors may be applied to a substrate, which is then rotated at high speed to spread the material evenly. The centrifugal force may help create a uniform thin film of the n and p type semiconductors. This method may be particularly useful for large-scale production due to its simplicity and scalability. Another alternative deposition technique may involve spray coating. In this method, a solution of the n and p type semiconductors may be aerosolized and sprayed onto the substrate. This technique may allow for the deposition of the n and p type semiconductors over large areas and may be suitable for applying the solar paint to irregularly shaped surfaces.

[0096] Inkjet printing may also be considered as an alternative deposition method. This technique may offer precise control over the placement of the n and p type semiconductors and may allow for the creation of complex patterns. Inkjet printing may be particularly useful for creating customized solar paint designs or for integrating the solar paint into existing structures.

[0097] In some aspects of the present disclosure, dip coating may be employed as a deposition method. This technique may involve immersing the substrate in a solution containing the n and p type semiconductors and then withdrawing it at a controlled rate. The thickness of the deposited layer may be controlled by adjusting the withdrawal speed and solution concentration.

[0098] Layer-by-layer assembly may be another alternative deposition technique. This method may involve the sequential deposition of oppositely charged materials, including the n and p type semiconductors, to build up a multilayer structure. This technique may offer precise control over the thickness and composition of the deposited layers.

[0099] In some aspects of the present disclosure, the choice of deposition method may depend on factors such as the desired thickness of the n and p type semiconductors, the substrate material, the scale of production, and the specific properties required for the solar paint. Each deposition method may offer unique advantages and may be selected based on the particular application and manufacturing constraints.

[0100] It may be noted that while these alternative deposition methods may differ from the electrophoresis - van der Waals forces assisted printing mechanism, they may still aim to achieve the same goal of creating a uniform and stable layer of the n and p type semiconductors within the solar paint structure. The selection of the most appropriate deposition method may involve considering factors such as efficiency, costeffectiveness, and compatibility with other components of the solar paint.

[0101] In some aspects of the present disclosure, combinations of different deposition techniques may be employed to optimize the performance of the solar paint. For example, one method may be used for depositing a base layer of the n and p type semiconductors, while another method may be used for adding a top layer with specific properties.

[0102] The development of new deposition techniques or modifications to existing methods may also be considered as potential alternatives. As nanotechnology and materials science continue to advance, novel approaches to the n and p type semiconductors deposition may emerge, potentially offering improved control, efficiency, or scalability in the production of solar paint.

[0103] Examples of the deposition methods may include, but are not limited to, spin coating, spray coating, inkjet printing, dip coating, layer-by-layer assembly, or combinations thereof. Aspects of the present disclosure are intended to include and / or otherwise cover any type of deposition method for n and p type semiconductors known to a person having ordinary skill in the art, without deviating from the scope of the present disclosure.

[0104] The solar paint technology disclosed herein may offer several advantages over traditional solar panel systems. In some aspects of the present disclosure, the solar paint may be applied to a wide variety of surfaces, potentially converting any structure into a solar energy harvesting device. This versatility may allow for the integration of solar energy generation into existing infrastructure without the need for dedicated solar panel installations.

[0105] The solar paint may be significantly lighter and more flexible than traditional solar panels. This property may enable its application on surfaces that cannot support the weight of conventional solar panels, such as certain types of roofs or vehicle exteriors. The lightweight nature of the solar paint may also reduce installation costs and structural requirements for solar energy systems.

[0106] In some aspects of the present disclosure, the solar paint may be more aesthetically pleasing than traditional solar panels. The ability to apply the solar paint in various colors or patterns may allow for seamless integration with existing architectural designs. This feature may increase the adoption of solar energy in urban environments where visual appeal may be a significant consideration.

[0107] The manufacturing process for the solar paint may be potentially more cost-effective than traditional solar panel production. The use of solution-based processing techniques and the ability to produce the paint in large quantities may lead to economies of scale, potentially reducing the overall cost of solar energy systems.

[0108] The solar paint may offer improved durability compared to traditional solar panels. The paint may be less susceptible to damage from impacts or extreme weather conditions. This increased durability may lead to longer lifespans for solar energy systems and reduced maintenance costs over time.

[0109] In some aspects of the present disclosure, the solar paint may be more efficient at capturing diffuse light or light from suboptimal angles compared to traditional solar panels. This property may allow for energy generation in conditions where conventional solar panels may be less effective, such as on cloudy days or when sunlight may be partially obstructed.

[0110] The solar paint technology may have numerous potential applications across various fields. In the construction industry, the solar paint may be applied to the exteriors of buildings, potentially turning entire structures into power generators. This application may be particularly useful in urban environments where space for traditional solar panels may be limited.

[0111] In the automotive industry, the solar paint may be applied to vehicle exteriors, potentially providing supplementary power for electric vehicles or powering auxiliary systems in conventional vehicles. This application may extend the range of electric vehicles or reduce fuel consumption in traditional vehicles.

[0112] The solar paint may find applications in the aerospace industry, potentially being applied to the exteriors of aircraft or spacecraft. In space applications, the lightweight nature of the solar paint may be particularly advantageous, potentially reducing launch costs and increasing payload capacity.

[0113] In some aspects of the present disclosure, the solar paint may be used in portable electronics and wearable technology. The flexibility and lightweight nature of the solar paint may allow for its integration into clothing, backpacks, or portable electronic devices, potentially providing on-the-go charging capabilities.

[0114] The solar paint may have applications in remote or off-grid locations where traditional power infrastructure may be unavailable or impractical. For example, the paint may be applied to temporary structures in disaster relief efforts, providing a quick and easy way to establish power generation in emergency situations.

[0115] In the agricultural sector, the solar paint may be applied to greenhouse structures or agricultural equipment, potentially providing power for irrigation systems, climate control, or other farming operations. This application may increase the sustainability and energy independence of agricultural operations.

[0116] The solar paint technology may also have potential applications in marine environments. The paint may be applied to the hulls of ships or offshore structures, potentially providing power for onboard systems or supplementing traditional power sources in remote marine locations.

[0117] In some aspects of the present disclosure, the solar paint may be used in urban planning and smart city initiatives. The paint may be applied to street furniture, traffic signals, or public transportation infrastructure, potentially creating a distributed network of power generation throughout urban areas. The versatility and potential cost-effectiveness of the solar paint technology may make it particularly suitable for large-scale renewable energy projects in developing regions. The ease of application and minimal infrastructure requirements may allow for rapid deployment of solar energy systems in areas lacking traditional power infrastructure.

[0118] In conclusion, the solar paint technology disclosed herein may offer numerous advantages over traditional solar panel systems and may have wide-ranging applications across various industries and sectors. The potential for widespread adoption of this technology may contribute significantly to the global transition towards renewable energy sources and sustainable development.

[0119] Thus, the solar paint 100 and the method 200 for preparing the solar paint 100 provide several significant technical advantages over traditional solar energy harvesting technologies. The solar paint offers unprecedented versatility, allowing for application on a wide variety of surfaces and structures, effectively converting them into solar energy generators without the need for dedicated panel installations. Its lightweight and flexible nature enables integration into surfaces that cannot support conventional solar panels, expanding the potential for solar energy adoption. The paint's ability to capture diffuse light and operate efficiently at suboptimal angles enhances energy generation in conditions where traditional panels may underperform. The manufacturing process, utilizing solution-based techniques and the n and p type semiconductors technology, potentially offers a more cost-effective and scalable production method compared to traditional solar panel fabrication. The paint's durability and resistance to environmental factors may lead to extended system lifespans and reduced maintenance requirements. Additionally, the incorporation of the n and p type semiconductors with varying band gaps in the active layer facilitates broad spectrum light absorption and multiple exciton generation, potentially increasing overall energy conversion efficiency. These technical advancements collectively contribute to a more adaptable, efficient, and economically viable solar energy harvesting solution, potentially accelerating the global transition towards sustainable energy sources. Aspects of the present disclosure are discussed here with reference to flowchart illustrations and block diagrams that depict methods, systems, and apparatus in accordance with various aspects of the present disclosure. The flowcharts and block diagrams presented in the figures depict the architecture, functionality, and operation of potential implementations of systems, methods, and apparatus according to different aspects of the present disclosure. In some alternative implementations, the order of functions within the blocks may differ from what is depicted. For instance, two blocks shown in sequence may be executed concurrently or in reverse order, depending on the required functionality. Each block, and combinations of blocks, can also be implemented using special-purpose hardware-based systems that perform the specified functions or tasks, or through a combination of specialized hardware and software instructions.

[0120] Although the preferred aspects have been detailed here, it should be apparent to those skilled in the relevant field that various modifications, additions, and substitutions can be made without departing from the scope of the disclosure. These variations are thus considered to be within the scope of the disclosure as defined in the following claims. Features or functionalities described in certain example aspects may be combined and re-combined in or with other example aspects. Additionally, different aspects and elements of the disclosed example aspects may be similarly combined and recombined. Further, some example aspects, individually or collectively, may form components of a larger system where other processes may take precedence or modify their application. Moreover, certain steps may be required before, after, or concurrently with the example aspects disclosed herein. It should be noted that any and all methods and processes disclosed herein can be performed in whole or in part by one or more entities or actors in any manner.

[0121] Although terms like "first," "second," etc., are used to describe various elements, components, regions, layers, and sections, these terms should not necessarily be interpreted as limiting. They are used solely to distinguish one element, component, region, layer, or section from another. For example, a "first" element discussed here could be referred to as a "second" element without departing from the teachings of the present disclosure.

[0122] The terminology used here is intended to describe specific example aspects and should not be considered as limiting the disclosure. The singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "includes," "comprising," and "including," as used herein, indicate the presence of stated features, steps, elements, or components, but do not exclude the presence or addition of other features, steps, elements, or components. As used herein, the term "or" is intended to be inclusive, meaning that "X employs A or B" would be satisfied by X employing A, B, or both A and B. Unless specified otherwise or clearly understood from the context, this inclusive meaning applies to the term "or."

[0123] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the relevant art. Terms should be interpreted consistently with their common usage in the context of the relevant art and should not be construed in an idealized or overly formal sense unless expressly defined here.

[0124] The terms "about" and "substantially," as used herein, refer to a variation of plus or minus 10% from the nominal value. This variation is always included in any given measure.

[0125] In cases where other disclosures are incorporated by reference and there is a conflict with the present disclosure, the present disclosure takes precedence to the extent of the conflict, or to provide a broader disclosure or definition of terms. If two disclosures conflict, the later-dated disclosure will take precedence.

[0126] The use of examples or exemplary language (such as "for example") is intended to illustrate aspects of the invention and should not be seen as limiting the scope unless otherwise claimed. No language in the specification should be interpreted as implying that any non-claimed element is essential to the practice of the invention.

[0127] While many alterations and modifications of the present invention will likely become apparent to those skilled in the art after reading this description, the specific aspects shown and described by way of illustration are not intended to be limiting in any way.

[0128] A number of implementations have been described. Nevertheless, it will be understood that various modifications may be made without departing from the scope of the disclosure. Accordingly, other implementations are within the scope of the following claims.

Claims

Claim:

1. A solar paint (100) comprising: a top layer (102) comprising a transparent conductor made of Indium Tin Oxide (ITO) with horizontal patterns printed using carbon ink; a bottom layer (106) comprising an insulating substrate, a bottom electrode, and a hole conductor; and an active layer (146) comprising n and p type semiconductors, wherein the n and p type semiconductors are dispersed in a colloidal suspension with surfactants to prevent aggregation, and wherein the colloidal suspension is prepared at a critical coagulation concentration (CCC) to ensure long-term stability.

2. The solar paint (100) as claimed in claim 1, wherein the carbon ink comprises graphene or multi-walled carbon nanotubes or any combination thereof.

3. The solar paint (100) as claimed in claim 2, wherein the top layer (102) further comprises a coating of silver nanoparticles for enhanced photon trapping.

4. The solar paint (100) as claimed in claim 1, wherein the bottom layer (106) comprises: a first sub-layer comprising the insulating substrate made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN); a second sub-layer comprising the bottom electrode made of stacked metal nanoparticles and aluminum-coated zinc oxide (ZnO); and a third sub-layer comprising the hole conductor made of PEDOT:PSS.

5. The solar paint (100) as claimed in claim 1, wherein the bottom electrode functions as both a conductor and a reflector for electron transport.

6. A method (200) of preparing a solar paint (100), the method comprising:preparing (202), one or more stock solutions (102) comprising n and p type semiconductors, or TiCh dispersed in N-N-dimethyl-formamide (DMF) solvent; determining (204), a critical coagulation concentration (CCC) of each of the one or more stock solutions by diluting each of the one or more stock solutions to multiple concentrations and monitoring stability using UV-Vis-NIR absorption data; preparing (206), a top layer (102) comprising a transparent conductor made of Indium Tin Oxide (ITO) with horizontal patterns printed using carbon ink; preparing (208), a bottom layer (106) comprising an insulating substrate, a bottom electrode, and a hole conductor; and preparing (210), an active layer (104) comprising the n-type and the p-type semiconducting materials dispersed in each of the one or more stock solutions at the determined CCC.

7. The method (200) as claimed in claim 6, wherein determining the critical coagulation concentration (CCC) comprises: preparing dilutions of each of the one or more stock solutions to concentrations of 5xl0A-5 molar, 5xl0A-6 molar, and 5xlOA-7 molar; bath sonicating each dilution for a predefined time period at a constant temperature; and monitoring stability of each dilution for a predefined period of time using UV - Vis-NIR absorption data.

8. The method (200) as claimed in claim 7, wherein preparing the top layer (102) further comprises: coating the ITO patterns with silver nanoparticles to enhance photon trapping; and annealing the top layer at 120°C on a hot plate.

9. The method (200) as claimed in claim 8, wherein preparing the bottom layer (106) comprises: forming a first sub-layer comprising the insulating substrate made of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN); forming a second sub-layer comprising the bottom electrode made of stacked metal nanoparticles and aluminum-coated zinc oxide (ZnO); and forming a third sub-layer comprising the hole conductor made of PEDOT:PSS.

10. The method (200) as claimed in claim 9, wherein preparing the active layer (110) further comprises: mixing n type semiconductors having a direct band gap of 1.5 eV with p type semiconductors having a direct band gap of 0.4 eV at room temperature; and dispersing the mixed n and p type semiconductors in each of the one or more stock solutions at the determined CCC to facilitate multiple exciton generation.

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