KR20240092276A - MXene-Integrated Transparent Photovoltaics and Manufacturing Method Thereof - Google Patents

Abstract

The present invention relates to an MXene-based transparent solar cell and its manufacturing method. More specifically, it uses MXene, a two-dimensional nanomaterial, as a front electrode to secure the transmittance of the transparent solar cell and easily collect light-generated carriers to generate power. It relates to an MXene-based transparent solar cell that can be effectively produced and a method of manufacturing the same.

Description

MXene-based transparent solar cell and manufacturing method thereof {MXene-Integrated Transparent Photovoltaics and Manufacturing Method Thereof}

The present invention relates to an MXene-based transparent solar cell and its manufacturing method. More specifically, it uses MXene, a two-dimensional nanomaterial, as a front electrode to secure the transmittance of the transparent solar cell and easily collect light-generated carriers to generate power. It relates to an MXene-based transparent solar cell that can be effectively produced and a method of manufacturing the same.

Unlike existing opaque solar cells, transparent solar cells can convert incident light into power without blocking the view. Conventionally, materials such as inorganic materials, organic materials, dyes, and perovskites are used in transparent solar cells, and in particular, ITO (indium tin oxide) is mainly used. However, ITO is expensive, can be a burden on the environment, and has the problem of being unsuitable for next-generation solar cell technology.

To replace ITO, various alternatives such as thin film metal oxides, conductive polymers, metal grids and nanowires, carbon nanotubes, and two-dimensional nanomaterials have been proposed. Among these, two-dimensional nanomaterials with unique optical, electrical, and mechanical properties are the most promising candidates, and have the advantage of being able to be manufactured at a relatively low price because they can be manufactured using a wet method. However, conventional two-dimensional nanomaterials also have a relatively complex production process, which makes them unsuitable for solar cell applications.

Recently, MXene has been attracting attention as a two-dimensional nanomaterial. MXene is composed of elements that are abundant and non-hazardous on Earth, and can enable the design of environmentally safe and inexpensive solar devices in addition to device efficiency. In particular, MXene has the characteristic of having higher electrical conductivity compared to conventional two-dimensional nanomaterials.

However, when using bare MXene in transparent solar cells, there is a problem that it is easily oxidized and hydrolyzed in an aqueous environment, so there is an urgent need to develop technology to solve this problem.

The present invention provides an MXene-based transparent solar cell and a method of manufacturing the same, which secures the transmittance of the transparent solar cell using MXene, a two-dimensional nanomaterial, as a front electrode and can easily collect light-generated carriers to effectively produce power. It is for that purpose.

In order to solve the above problems, an embodiment of the present invention is an MXene-based transparent solar cell, which includes a transparent substrate layer; a first transparent electrode layer disposed on the transparent substrate layer and including FTO; an n-type oxide layer disposed on the transparent electrode layer and containing TiO ₂ ; a p-type oxide layer disposed on the n-type oxide layer and including NiO; and a second transparent electrode layer disposed on the p-type oxide layer and including a two-dimensional nanomaterial, wherein the two-dimensional nanomaterial includes MXene.

In some embodiments of the present invention, the two-dimensional nanomaterial may include a TFA-treated Ti ₃ C ₂ T _x MXene solution.

In some embodiments of the present invention, the second transparent electrode layer may be formed by spin coating the TFA-treated Ti ₃ C ₂ T _x MXene solution on the p-type oxide layer and then drying it.

In some embodiments of the present invention, the MXene-based transparent solar cell can implement a photoelectric device, and the photoelectric device is a photoelectric device that operates on its own in the absence of external voltage or a photoelectric device that improves characteristics by applying an external voltage. It may apply.

In some embodiments of the present invention, the MXene-based transparent solar cell may include an n-TiO ₂ /p-NiO heterojunction structure formed by the n-type oxide layer and the p-type oxide layer.

In order to solve the above problems, an embodiment of the present invention provides a method of manufacturing an MXene-based transparent solar cell, comprising the steps of disposing a transparent substrate layer; disposing a first transparent electrode layer including FTO on the transparent substrate layer; Disposing an n-type oxide layer containing TiO ₂ on the transparent electrode layer; Disposing a p-type oxide layer containing NiO on the n-type oxide layer; and disposing a second transparent electrode layer containing a two-dimensional nanomaterial on the p-type oxide layer, wherein the two-dimensional nanomaterial includes MXene. A method of manufacturing an MXene-based transparent solar cell is provided. .

In some embodiments of the present invention, the two-dimensional nanomaterial may include a TFA-treated Ti ₃ C ₂ T _x MXene solution.

In some embodiments of the present invention, the MXene-based transparent solar cell may include an n-TiO ₂ /p-NiO heterojunction structure formed by the n-type oxide layer and the p-type oxide layer.

According to one embodiment of the present invention, an MXene-based transparent solar cell is provided that uses MXene, a two-dimensional nanomaterial, as a front electrode to secure the transmittance of the transparent solar cell and easily collect light-generated carriers to effectively produce power. can be provided.

According to one embodiment of the present invention, the optical properties and electrical properties of an MXene-based transparent solar cell are improved by controlling the number of spin coatings of the TFA-treated Ti ₃ C _{2 T} It can have the effect of improving characteristics.

In one embodiment of the present invention, power can be produced from ultraviolet rays while selectively passing visible light by lowering the sheet resistance of MXene and improving the contact between MXene and p-NiO/n-TiO ₂ heterojunction.

According to one embodiment of the present invention, an MXene-based transparent solar cell includes a p-NiO/n-TiO ₂ heterojunction structure, thereby achieving the effect of spontaneously forming a built-in potential and converting incident photon energy into power. It can be performed.

According to one embodiment of the present invention, an MXene-based transparent solar cell can operate in a self-powered mode by inducing a high photovoltage, thereby demonstrating the effect of performing the role of a self-driving photodetector.

According to one embodiment of the present invention, the MXene-based transparent solar cell can obtain a fast optical response in self-powered mode, enabling self-supporting photovoltaic cells.

According to one embodiment of the present invention, MXene-based transparent solar cells have white light or color coordinates similar to sunlight, and may be suitable for application to windows of buildings and vehicles as an on-site power supply system.

Figure 1 schematically shows the layered structure of an MXene-based transparent solar cell according to an embodiment of the present invention.
Figure 2 shows details of the second transparent electrode layer according to an embodiment of the present invention.
Figure 3 shows the distribution of elements on the surface of the second transparent electrode layer according to an embodiment of the present invention.
Figure 4 shows details about an MXene-based transparent solar cell according to an embodiment of the present invention, its cross-sectional FE-SEM image, transmittance spectrum according to the number of coatings of MXene, and CIE chromaticity diagram.
Figure 5 shows details on the XRD patterns of the n-type oxide layer and the p-type oxide layer according to an embodiment of the present invention.
Figure 6 shows details on mobility according to resistance of the second transparent electrode layer according to an embodiment of the present invention.
Figure 7 shows details on transmittance according to resistivity of the second transparent electrode layer according to an embodiment of the present invention.
Figure 8 shows the IV characteristics of an MXene-based transparent solar cell according to an embodiment of the present invention.
Figure 9 shows details on the dielectric constant of the second transparent electrode layer according to an embodiment of the present invention.
Figure 10 shows details on the performance of an MXene-based transparent solar cell according to an embodiment of the present invention.
Figure 11 shows the transient photovoltage profile and response speed-light frequency dependence of an MXene-based transparent solar cell according to an embodiment of the present invention.
Figure 12 shows details on a stability test of an MXene-based transparent solar cell according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Various embodiments and/or aspects are now disclosed with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth to facilitate a general understanding of one or more aspects. However, it will also be appreciated by those skilled in the art that this aspect(s) may be practiced without these specific details. The following description and accompanying drawings set forth in detail certain example aspects of one or more aspects. However, these aspects are illustrative and some of the various methods in the principles of the various aspects may be utilized, and the written description is intended to encompass all such aspects and their equivalents.

Additionally, various aspects and features may be presented by a system that may include multiple devices, components and/or modules, etc. It is also understood that various systems may include additional devices, components and/or modules, etc. and/or may not include all of the devices, components, modules, etc. discussed in connection with the drawings. It must be understood and recognized.

As used herein, “embodiments,” “examples,” “aspects,” “examples,” etc. may not be construed to mean that any aspect or design described is better or advantageous over other aspects or designs. .

Additionally, the terms "comprise" and/or "comprising" mean that the feature and/or element is present, but exclude the presence or addition of one or more other features, elements and/or groups thereof. It should be understood as not doing so.

Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, a first component may be named a second component without departing from the scope of the present invention, and similarly, the second component may also be named a first component. The term and/or includes any of a plurality of related stated items or a combination of a plurality of related stated items.

In addition, in the embodiments of the present invention, unless otherwise defined, all terms used herein, including technical or scientific terms, are generally understood by those skilled in the art to which the present invention pertains. It has the same meaning as becoming. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless clearly defined in the embodiments of the present invention, have an ideal or excessively formal meaning. It is not interpreted as

As a material for transparent solar cells, ITO was conventionally used as a transparent electrode layer. However, ITO is not suitable for next-generation solar cell technology in terms of cost and environment, so MXene, a two-dimensional nanomaterial, has recently been attracting attention as an alternative to ITO.

However, when using bare MXene in transparent solar cells, there is a problem in that oxidation and hydrolysis occur in an aqueous environment.

To solve this problem, the present invention implemented a transparent solar cell using TFA-treated MXene.

More specifically, the present invention provides a transparent photoelectric device including a structure in which MXene is disposed as a front electrode and an n-TiO ₂ /p-NiO heterojunction is placed in contact with the MXene, and the transparent photoelectric device includes the above Through the structure of , an MXene-based transparent solar cell (1) can be implemented. That is, the present invention provides an MXene-based transparent solar cell (1).

The MXene-based transparent solar cell (1) of the present invention includes MXene formed by a TFA-treated Ti ₃ C ₂ T _x MXene solution, and can solve problems when bare MXene is applied to a conventional transparent solar cell. In other words, the present invention provides the possibility of stable use of MXene, a two-dimensional nanomaterial, as a transparent solar cell, and based on this, can provide an MXene-based transparent solar cell (1) for the first time.

In addition, the MXene-based transparent solar cell (1) is suitable for implementing an optically transparent system that produces electrical energy, and can be applied, for example, to bioelectronics, buildings, vehicles, and display windows, etc. .

Meanwhile, in the present invention, an MXene-based transparent solar cell 1 that functions as a photodetector can be implemented through the above-mentioned MXene-based structure, as will be described later.

Hereinafter, the MXene-based transparent solar cell 1 according to an embodiment of the present invention will be described in more detail.

Figure 1 schematically shows the layered structure of an MXene-based transparent solar cell 1 according to an embodiment of the present invention.

An MXene-based transparent solar cell (1) according to an embodiment of the present invention includes a transparent substrate layer (100); a first transparent electrode layer 200 disposed on the transparent substrate layer 100 and including FTO; An n-type oxide layer 300 disposed on the transparent electrode layer and containing TiO ₂ ; a p-type oxide layer 400 disposed on the n-type oxide layer 300 and containing NiO; and a second transparent electrode layer 500 disposed on the p-type oxide layer 400 and containing a two-dimensional nanomaterial. The two-dimensional nanomaterial may include MXene.

In this configuration, the present invention can implement an MXene-based transparent solar cell (1) that can secure the transmittance of the transparent solar cell and easily collect light-generated carriers to effectively produce power.

The first transparent electrode layer 200 corresponds to the back electrode of a transparent solar cell and can be connected to the anode terminal.

The n-type oxide layer 300 and the p-type oxide layer 400 form a pn heterojunction. Preferably, the MXene-based transparent solar cell 1 according to an embodiment of the present invention is n-TiO ₂ /p-NiO formed by the n-type oxide layer 300 and the p-type oxide layer 400. It may contain a heterojunction structure.

In this configuration, the MXene-based transparent solar cell 1 can have the structure of a basic transparent solar cell and thus exhibit photovoltaic characteristics. In particular, the MXene-based transparent solar cell (1) includes an n-TiO ₂ /p-NiO heterojunction structure and can produce power from ultraviolet rays.

The second transparent electrode layer 500 corresponds to the front electrode of a transparent solar cell and can be connected to the cathode terminal.

Additionally, the second transparent electrode layer 500 includes MXene, a two-dimensional nanomaterial. MXene can be uniformly embedded in inorganic metal oxide layers to create a platform for transparent solar cells and photodetectors.

As mentioned above, MXene not only has excellent optical transparency and conductivity, but can also be formed on a large scale, making it suitable for application as a transparent electrode layer in transparent solar cells. In addition to being basically a two-dimensional nanomaterial, MXene has hydrophilicity due to the presence of surface functional groups (-O and -OH), and due to these characteristics, it can be wet-processed through various methods including drop casting, spin coating, and inkjet printing. Processing is possible.

However, when MXene is used as bare MXene, it can be easily oxidized and hydrolyzed in an aqueous environment, so in the present invention, MXene treated with TFA (Trifluoroacetic acid) was used. Preferably, the two-dimensional nanomaterial according to an embodiment of the present invention includes a TFA-treated Ti ₃ C ₂ T _x MXene solution.

TFA-treated MXene exhibits 1) high conductivity of 8900 Scm ^-1 , 2) excellent dispersion stability in ethanol, and 3) oxidation resistance during storage and processing through release of AlF3, etching by-products, and modulation of surface functional groups. There is a characteristic.

That is, the second transparent electrode layer 500 includes MXene formed by a TFA-treated Ti ₃ C ₂ T _x MXene solution. The manufacturing method of the second transparent electrode layer 500 will be described later.

As such, the present invention provides an MXene-based transparent solar cell (1) that uses MXene, a two-dimensional nanomaterial, as a front electrode to secure the transmittance of the transparent solar cell and easily collect light-generated carriers to effectively produce power. can do.

Figure 2 shows details about the second transparent electrode layer 500 according to an embodiment of the present invention, and Figure 3 shows the distribution of elements on the surface of the second transparent electrode layer 500 according to an embodiment of the present invention. Show the details.

The shape of the second transparent electrode layer 500 was examined using field emission scanning electron microscopy (FE-SEM; JSM-7610F, JEOL), high-resolution transmission electron microscopy (HR-TEM) (JEM-2100F, JEOL), and atomic force microscopy (AFM). , Multimode-N3-AM, Bruker).

Figure 2(a) shows the ultra-low thickness of the second transparent electrode layer 500 (hereinafter referred to as MXene), its transparency to electron beams, and its lateral dimensions extending several micrometers.

As shown in Figure 2(a), the single crystallinity of MXene can be confirmed through a dot selected area electron diffraction (SAED) pattern.

Figure 2(b) shows the AFM height profile of MXene.

The AFM height profile measured along the white line shows that the height of MXene relative to the substrate is ~2.4 nm, which corresponds to a thickness greater than that of monolayer MXene (~1 nm). This result may be due to surface adsorbents (e.g. water molecules) trapped underneath the MXene, as is known. MXene preferably has an in-plane layered structure typical of two-dimensional nanomaterials.

Figures 2(c) and 3 show the distribution of Ti, C, O, F, and Cl elements on the MXene surface.

As shown in Figures 2(c) and 3, Ti, C, O, F, and Cl elements are uniformly distributed on the MXene surface, which means that MXene has -O (and/or -OH), -F on the surface. It may mean that it may have and -Cl.

Figure 2(d) shows the XRD pattern of MXene.

The crystal structure of MXene was confirmed using powder X-ray diffraction (XRD; D2 Phaser, Bruker) using Cu Kα radiation (λ = 0.1542 nm).

As shown in Figure 2(d), due to the aligned stacked structure of MXene, MXene generates an XRD pattern including a sharp (002) peak. The absence of other impurity peaks confirms the successful etching and peeling of the MAX phase, and the absence of oxidized by-products of MXene or etching by-products of the MAX phase within MXene. The above characteristics of single-layer MXene and the excellent electrical conductivity (~8900 Scm ^-1 ) of TFA-treated Ti ₃ C _{2 T} It can be supported.

Figure 4 shows details of an MXene-based transparent solar cell (1) according to an embodiment of the present invention, its cross-sectional FE-SEM image, transmittance spectrum according to the number of coatings of MXene, and CIE chromaticity diagram, and Figure 5 shows Details of the XRD patterns of the n-type oxide layer 300 and the p-type oxide layer 400 according to an embodiment of the present invention are shown, and Figure 6 shows the second transparent electrode layer ( 500), and Figure 7 shows details about the transmittance according to the resistance of the second transparent electrode layer 500 according to an embodiment of the present invention.

Figure 4(a) schematically shows an MXene-based transparent solar cell 1 according to an embodiment of the present invention.

MXene is a structure corresponding to the front electrode of a transparent solar cell, as shown in Figure 4(a), and is formed by spin coating, which will be described later. As shown in the inset of FIG. 4(a), the MXene-based transparent solar cell 1 of the present invention can have excellent transparency. At this time, the MXene-based transparent solar cell 1 includes an n-TiO ₂ /p-NiO heterojunction formed by an n-type oxide layer 300 and a p-type oxide layer 400, and the n-TiO ₂ /p -NiO heterojunction spontaneously forms an internal potential due to the difference in work function value and acts as a photoactive component of a solar cell, converting incoming photon energy into power. In the present invention _, by using TFA-treated Ti ₃ C ² _T Can produce electricity.

Figure 4(b) shows a FE-SEM image of a transparent solar cell implemented with the MXene-based transparent solar cell (1).

In the present invention, the FE-SEM image was measured using FE-SEM (JSM-7001F, JEOL), and the cross-section and top topology of the transparent solar cell were confirmed through this.

As shown in FIG. 4(b), the cross-sectional FESEM image of the transparent solar cell shows the n-TiO ₂ /p-NiO heterojunction on the transparent substrate layer 100 (hereinafter referred to as FTO/glass substrate) with a transparent electrode layer formed on one side. It clearly shows that this was formed.

In addition, the right view of Figure 4(b) shows planar images of each transparent solar cell before and after MXene is deposited, showing smooth contact between MXene and n-TiO ₂ /p-NiO heterojunction. You can check that. MXene formed by spin coating can be composed of Ti ₃ C ₂ T _x nanosheets with domains parallel to the n-TiO ₂ /p-NiO surface having a size of several micrometers. Preferably, the two-dimensional nanomaterial according to an embodiment of the present invention may include TFA-treated Ti ₃ C ₂ T _x MXene.

Meanwhile, _as shown in Figure 5, the The XRD pattern of the p-type oxide complies with the COD-AMSCD 9008693 standard and has a lattice parameter of a = 4.211. It is desirable to have a cubic crystal system. Through the XRD patterns of each of these n-type oxides and p-type oxides, the quality crystal structure and chemical purity of NiO and TiO ₂ can be confirmed.

Figures 4(c) and 4(d) show the transmittance spectrum according to the number of coatings of MXene.

The UV-visible spectrum of MXene was determined in the wavelength range of 200 to 1200 nm using a PerkinElmer Lambda 750 spectrometer, and the transmission spectrum was determined in the wavelength range of 300 to 1200 nm using a UV-vis diffuse reflectance spectrophotometer (UV-2600, Shimadzu). λ) range, and the conductivity of MXene was measured under ambient conditions using a four-point probe (CMTSR200N, Advanced Instrument Technology).

Figure 4(c) shows the transmittance spectrum according to the number of coatings of MXene in the structure of the transparent substrate layer 100/second transparent electrode layer 500. MXene can exhibit a wide absorption peak due to surface plasmon resonance in the wavelength range of 750 to 800 nm.

In one embodiment of the present invention, the second transparent electrode layer 500 may be formed by spin coating the TFA-treated Ti ₃ C ₂ T _x MXene solution on the p-type oxide layer 400 and then drying it.

More specifically, the TFA-treated Ti ₃ C ₂ T _x MXene solution may be coated with a number of coatings selected from the range of 4 to 8. When the number of coatings of MXene is increased, the conductivity of the second transparent electrode layer 500 increases, while the thickness of the second transparent electrode layer 500 may become thick, thereby reducing transparency. Considering this, in the present invention, the second transparent electrode layer 500 was formed by adjusting the number of spin coatings of the TFA-treated Ti ₃ C ₂ T _x MXene solution in order to derive appropriate conditions.

In Figure 4(c), based on the transmittance at a wavelength of 550 nm, MXene formed by coating 4 times (290Ω/□ in Figure 4(c), black line) is 55%, and MXene formed by coating 6 times (Figure 4(c) 4(c), 200Ω/□, red line) shows a transmittance of 45%, and MXene formed by coating eight times (90Ω/□, blue line in FIG. 4(c)) shows a transmittance of 37%. In particular, in the case of MXene formed by coating four times, it has a low mobility value of 0.03cm ² V ^-1 s ^-1 and can have a greatly improved resistance of 0.28cm ² V ^-1 s ^-1 (see FIG. 6 ). At this time, the second transparent electrode layer 500 according to an embodiment of the present invention preferably has conductivity corresponding to the known Ti ₃ C ₂ T _x (see FIG. 7).

As such, it is important to balance the light transmittance and electrical conductivity of MXene, which can greatly affect the performance of transparent solar cells implemented with MXene-based transparent solar cells (1).

That is, in one embodiment of the present invention, by controlling the number of spin coatings of the TFA-treated Ti ₃ C ₂ T _x MXene solution when forming the second transparent electrode layer 500 containing MXene, an MXene-based transparent solar cell (1 ) can have the effect of improving the optical and electrical properties of the device.

Figure 4(d) shows the transmittance spectrum according to the number of coatings of MXene in the structure of the transparent solar cell of the present invention.

The transparency of the transparent solar cell can be confirmed through Figure 4(d). In addition, it can be seen that the transparent solar cell has strong absorption characteristics in the ultraviolet wavelength range, while its transmittance rapidly decreases in the wavelength range of less than 400 nm. These characteristics are due to the bandgap matching of TiO ₂ (bandgap of 3.2 eV). Accordingly, the transparent solar cell can be classified as a selective wavelength solar cell that absorbs ultraviolet light and passes light in the visible range (λ>400 nm). The average visible light transmittance (AVT) of the transparent solar cell is calculated as follows.

where T, P, S, and λ correspond to transmittance, photopic response, solar flux, and wavelength, respectively. The AVT of the transparent solar cell can be improved by adjusting the number of coatings of MXene. More specifically, in the number of coatings ranging from 4 to 8, the MXene formed by coating 4 times (in FIG. 4(d)) 290Ω/□, red line) had the highest AVT (39.73%), and MXene formed by the above 8 coatings (90Ω/□, green line in Figure 4(d)) had the lowest AVT (24.38%). You can have it.

In this way, it can be seen that, overall, the transparent solar cell implemented with the MXene-based transparent solar cell (1) of the present invention exhibits excellent transparency. That is, the MXene-based transparent solar cell (1) can implement a transparent solar cell and photodetector by embedding MXene uniformly in the inorganic metal oxide layer, and has excellent transparency (39.73%), making it suitable for window-type solar cell applications. It may be suitable for application.

Meanwhile, in the present invention, the visual appearance and color compatibility of the transparent solar cell implemented with the MXene-based transparent solar cell (1) was confirmed in accordance with the CIE (International Commission on Illumination) 1931 standard.

Figure 4(e) shows the CIE spatial chromaticity diagram of the transparent solar cell according to the number of MXene coatings. The standard presents the color coordinates of interest (x,y) as a function of tristimulus values to show the visual appearance.

As shown in FIG. 4(e), the MXene-based transparent solar cell 1 includes MXene formed by coating 4 times (0.368, 0.382), and MXene formed by coating 6 times (0.370, 0.383). , and MXene formed by coating 8 times shows the color coordinates of (0.373, 0.386). The above color coordinates were found to be mapped very similarly to the white light spectrum (D65) or standard sunlight (AM 1.5G), denoted as (0.325, 0.315) and (0.348, 0.347), respectively, in CIE space.

That is, in one embodiment of the present invention, the MXene-based transparent solar cell 1 has a color coordinate similar to white light or sunlight, and may be suitable for application to windows of buildings and vehicles as an on-site power supply system.

Figure 8 shows the I-V characteristics of the MXene-based transparent solar cell 1 according to an embodiment of the present invention, and Figure 9 shows the dielectric constant of the second transparent electrode layer 500 according to an embodiment of the present invention. It shows the details.

In the transparent solar cell, MXene can affect the photoelectric properties of the n-TiO ₂ /p-NiO heterojunction.

Figure 8(a) shows the IV profile of the MXene-based transparent solar cell (1) in dark conditions. The IV profile was measured with a potentiostat/galvanostat (PGStat; ZIVE SP2, WonA Tech.) using linear sweep voltammetry at a scan rate of 100 mVs ^-1 .

As shown in Figure 8(a), even if the resistance value of MXene decreases from 290Ω/□ (black line in Figure 8(a)) to 200Ω/□ (red line in Figure 8(a)), the dark current of the transparent solar cell It can be seen that maintains the value of 0.8μA cm ^-2 . In this way, even if the resistance value of MXene decreases from 290Ω/□ to 200Ω/□, the quality of n-TiO ₂ /p-NiO heterojunction can be maintained.

On the other hand, when the resistance value of MXene decreases from 200Ω/□ to 90Ω/□ (blue line in FIG. 8(a)), it can be seen that the dark current of the transparent solar cell increases to 5μA cm ^-2 . If the dark current increases, the photovoltaic effect of the transparent solar cell may worsen.

Figure 8(b) shows the I-V profile of the MXene-based transparent solar cell 1 under UV light condition with a wavelength of 365 nm. Specifically, in the present invention, a 365 nm light source was used, and the light source was corrected using a UV power meter (UV 340; Lutron) to show the I-V profile in Figure 8(b).

Photoinduced I-V in the fourth quadrant confirms that the transparent solar cell can operate as a generator with negative power output (i.e., positive voltage times negative current) to power an external load. You can.

In this way, the photoelectric effect of the transparent solar cell can be adjusted depending on the conductivity of MXene. More specifically, under the same lighting conditions as in Figure 8(b), when the resistance value of MXene is 200Ω/□ (red line in Figure 8(b)), the short-circuit current (I _SC ) of 0.3mAcm ^-2 and While it has the highest photocurrent, when the resistance value of MXene is 290Ω/□ (black line in FIG. 8(b)), it can have the lowest short-circuit current (I _SC ) of 0.15mAcm ^-2 . However, if the resistance value of MXene decreases further than 200Ω/□ (blue line in FIG. 8(b)), the photocurrent and photovoltage may decrease, thereby deteriorating the overall photovoltaic effect.

Considering this, the MXene set is preferably set to have an I _photo /I _dark ratio of 375, which means that the MXene-based transparent solar cell (1) has high sensitivity to ultraviolet light, which is important in new optoelectronic applications. It can mean something.

That is, in one embodiment of the present invention, by lowering the sheet resistance of MXene and improving the contact between MXene and p-NiO/n-TiO ₂ heterojunction, it is possible to selectively pass visible light and produce power from ultraviolet rays.

Figure 8(c) shows the photo-generated power profile by the n-TiO ₂ /p-NiO heterojunction of the MXene-based transparent solar cell (1).

As shown in Figure 8(c), a transparent solar cell containing MXene with a resistance value of 200Ω/□ (red line in Figure 8(c)) can generate energy most efficiently. More specifically, a transparent solar cell containing MXene with a resistance value of 200Ω/□ can generate power of 18μWcm ^-2 when ultraviolet light is incident, which is equivalent to MXene with a resistance value of 290Ω/□. 1.3 and 2.5 times, respectively, compared to a transparent solar cell containing MXene (black line in Figure 8(c)) and a transparent solar cell containing MXene with a resistance value of 90Ω/□ (blue line in Figure 8(c)), respectively. Corresponds to higher power production.

Since the MXene-based transparent solar cell 1 implements functions corresponding to conventional solar cells as described above, UPCE (UV power conversion efficiency) can be calculated through the existing equation below.

Here, P _max and P _light are the light generated power and incident light intensity of the transparent solar cell, respectively. Table 1 shows photovoltaic characteristic values according to the number of coatings (resistance value) of MXene in the transparent solar cell implemented by the MXene-based transparent solar cell (1) of the present invention.

MXene resistance value
(Ω/□) _J.S.C.
(mA/ ^cm2 ) _VOC
(V) FF
(%) η
(%) 290 0.15 0.21 25.9 0.34 200 0.2 0.33 26.8 0.7 90 0.1 0.16 25.7 0.17

In one embodiment of the present invention, a transparent solar cell containing MXene with a resistance value of 200Ω/□ can have UPCE of 0.7% for a UV intensity of 2.5mWcm ^-2 , which is comparable to that of conventional NiO using AgNW as an electrode. /TiO ₂ Corresponds to the UPCE value corresponding to a transparent solar cell containing a heterojunction.

As shown in FIG. 4(b), the transparent solar cell has low conductivity, while MXene is formed to completely cover the surface of the n-TiO ₂ /p-NiO heterojunction. Because of this, MXene, as an electrode that extracts power, can have characteristics similar to those of AgNW, which has limited conductivity at the microscopic level due to numerous large pores.

Figure 8(d) shows the light-generated power profile of a transparent solar cell containing MXene with a resistance value of 200 Ω/□ depending on the intensity of ultraviolet rays.

A.J.A. The Woollam Alpha-SE ellipsometer was used to estimate MXene through modeling of reflectance data by the CompleteEase software package.

In one embodiment of the present invention, the second transparent electrode layer 500 may have a thickness of 1 to 100 nm, and preferably, in the transparent solar cell, the second transparent electrode layer 500 has a thickness of 21.2 nm. It is desirable to have a thickness. In addition, as shown in FIG. 9, it was confirmed that the ellipse measurement results, including real (ε ₁ ) and imaginary (ε ₂ ) dielectric constants, were consistent with the known spectroscopic ellipse measurement model. As shown in FIG. 8(d), the transparent solar cell can improve power generation ability as the intensity of incident ultraviolet rays increases, and can convert the incident ultraviolet rays into power with a wide range of intensities.

In this way, the transparent solar cell can collect light-generated power even under various ultraviolet conditions, and through this, the reliability of the MXene electrode can be confirmed. That is, the MXene-based transparent solar cell 1 according to an embodiment of the present invention may be suitable for use in various application fields. For example, the MXene-based transparent solar cell (1) can generate power of about 30 μW cm ^-2 from UV light, and the power is in a range that can sufficiently drive the functions of smart windows and the Internet of Things. corresponds to

In addition, the transparent solar cell can improve power generation by adopting a functional light absorption layer such as 2D nanomaterials and Si thin film.

Figure 10 shows details on the performance of the MXene-based transparent solar cell 1 according to an embodiment of the present invention.

In order to confirm the effect of MXene on the performance of the transparent solar cell, the series resistance (R _S ) of the transparent solar cell was estimated to confirm charge transfer between MXene and the transparent solar cell.

The series resistance of the MXene-based transparent solar cell 1 according to an embodiment of the present invention may be affected by contact between the n-TiO ₂ /p-NiO heterojunction and the electrode. More specifically, the FTO of the transparent solar cell preferably has a conductivity of 7Ω/□, and as a result, the series resistance may be affected by contact between NiO and MXene. The series resistance is a factor that plays an important role in the performance of a transparent solar cell. In particular, when the series resistance is reduced, the I _SC and FF of the transparent solar cell may increase.

Figure 10(a) shows the lnI-V profile of the MXene-based transparent solar cell (1) according to the number of MXene coatings (resistance value), and RS was estimated by determining its slope.

More specifically, as shown in Figure 10(a), a transparent solar cell containing MXene with a resistance value of 290Ω/□ (red in Figure 10(a)), containing MXene with a resistance value of 200Ω/□. The series resistance values of the transparent solar cell (blue in Fig. 10(a)) and the transparent solar cell containing MXene (yellow in Fig. 10(a)) with a resistance value of 90 Ω/□ are 1391, 177, and 345 Ω, respectively. It was found that

In other words, when the resistance is lowered from 290Ω/□ to 200Ω/□ by increasing the number of MXene coatings, the performance of the transparent solar cell can be improved, such as by reducing the series resistance value and allowing more photo-generated charges to be collected.

However, when the resistance is further lowered from 200Ω/□ to 90Ω/□ by further increasing the number of MXene coatings, the series resistance value increases and charge transfer between NiO/TiO ₂ /FTO and MXene is hindered, resulting in As shown in FIG. 8(b) described above, the performance of the transparent solar cell may deteriorate. This increase in series resistance can be considered to be due to the fact that charges must move more in MXene, which has a relatively thick thickness. Additionally, in MXene, which has a relatively thicker thickness, relatively more MXene nanosheets overlap, which may lead to a longer collection length of carriers and cause surface defects at the contact interface, further promoting charge transfer between NiO/TiO ₂ and the MXene electrode. It can be a hindrance.

Figure 10(b) shows an energy band diagram of the MXene-based transparent solar cell 1 according to an embodiment of the present invention.

As shown in FIG. 10(b), TiO ₂ absorbs ultraviolet rays and generates electron-hole pairs (corresponding to photogenerated electron-hole pairs). These photogenerated electron-hole pairs can be separated by a built-in electric field at the NiO/TiO ₂ interface established through the Fermi level difference between p-type NiO and n-type TiO ₂ . Additionally, the difference in the Fermi level can result in a built-in potential of 0.45 eV at the NiO/TiO interface, and the built-in potential prevents electrons from conducting from TiO ₂ to NiO and holes from conducting in the opposite direction. It corresponds to the potential value suitable for the following.

That is, in one embodiment of the present invention, the MXene-based transparent solar cell 1 includes a p-NiO/n-TiO ₂ heterojunction structure, thereby spontaneously forming a built-in potential and converting incident photon energy into power. It can be effective.

In addition, the MXene-based transparent solar cell 1 can operate in a self-powered mode by inducing a high photovoltage, which can serve as a self-driving photodetector.

The work function of the known TFA-treated Ti ₃ C ₂ T _x MXene is about 4.8 eV, which corresponds to the effective work function for collecting photogenerated holes in NiO. As a result, the photovoltage and photocurrent of a transparent solar cell can be extracted using MXene.

Figure 11 shows the transient photovoltage profile and response speed-light frequency dependence of the MXene-based transparent solar cell 1 according to an embodiment of the present invention, and Figure 12 shows the details of the photovoltage profile and the response speed-optical frequency dependence of the MXene-based transparent solar cell 1 according to an embodiment of the present invention. Details on the stability test of the MXene-based transparent solar cell (1) are shown.

Meanwhile, the MXene-based transparent solar cell 1 according to an embodiment of the present invention can supply power to electronic devices as a solar cell.

That is, the MXene-based transparent solar cell (1) according to an embodiment of the present invention implements a high-performance photoelectric device with a p-NiO/n-TiO ₂ heterojunction structure, serving as a photodetector capable of improved operation characteristics and self-driving. can do. In this case, the transparent solar cell constitutes an energy-efficient and highly sensitive optical sensor that can be applied in communications, environmental monitoring, and image processing, and its simultaneous function in power generation and active sensing applications makes it suitable for application as a sustainable and portable electronic product. do.

In order to investigate the role of the MXene-based transparent solar cell 1 as a photodetector, pulsed UV light of various frequencies is irradiated when the MXene-based transparent solar cell 1 operates in solar cell mode. responses were analyzed. The transient photovoltage and photocurrent were confirmed using an oscilloscope (2 GHz bandwidth, TBS 1102B-EDU, Tektronix) and PGStat (chronoamperometry, zero bias).

Figure 11(a) shows the transient photovoltage of the transparent solar cell for frequencies of 10Hz and 0.5kHz, respectively.

As shown in FIG. 11(a), the MXene-based transparent solar cell 1 shows repeatable transient photovoltage at high UV light frequencies, confirming that it has high-speed response.

Figure 11(b) shows the rise time (τ _r ) and fall time (τ _f ) of the MXene-based transparent solar cell 1 according to the optical frequency. The rise time was determined from the rise interval of the transient photovoltage profile from 10% to 90% of the maximum photovoltage, and the fall time corresponded to the rise time for the profile decreasing from 90% to 10% of the maximum transient photovoltage. It was decided in this way.

As shown in FIG. 11(b), the response speed of the MXene-based transparent solar cell 1 may greatly decrease as the lighting frequency increases. In particular, the rise time and fall time of the MXene-based transparent solar cell were 80 and 130 μs, respectively, at a frequency of 1 kHz.

In this way, in one embodiment of the present invention, the MXene-based transparent solar cell (1) can obtain a fast optical response (rise time of 80 μs and fall time of 130 μs) in self-powered mode, making self-supporting photovoltaic possible. The self-power mode corresponds to a state in which the MXene-based transparent solar cell 1 is capable of self-driving.

The characteristics of the MXene-based transparent solar cell (1) can be further verified through FIG. 11(c). Figure 11(c) shows the transient photocurrent of the MXene-based transparent solar cell 1 in zero bias operating mode.

As shown in FIGS. 11(c) and 12, the MXene-based transparent solar cell 1 shows a consistent photocurrent of 75 μAcm ^-2 for 10,000 cycles, confirming that it has excellent stability. Accordingly, the reactivity (R) and detectability (D) of the MXene-based transparent solar cell (1) were calculated according to the equations below.

where P, I _dark , and q are the light intensity, dark current, and elementary charge (coulombs), respectively.

Table 2 below summarizes the photodetector characteristics of the MXene-based transparent solar cell 1 according to an embodiment of the present invention and a plurality of comparative examples.

structure λ(nm),
bias(V) T
(%) R
(AW ^-1 ) Detectability
(Jones) τ _r /τ _f note Au/NiO/ _TiO2 /TiOx _/ FTO 365, 0 - 6x10 ^-3 5.5x10 ¹¹ <0.1/0.1s Comparative Example 1 Ag/NiO/TiO ₂ nanowell/Ti foil 350, 0 - 42x10 ^-6 1.1x10 ⁹ 1.2/7.1s Comparative Example 2 Au/ _TiO2 /P3HT 350, 0 - 0.25x10 ^-3 1.1x10 ¹⁰ 0.4/2.12s Comparative Example 3 AgNWs/NiO/TiO ₂ /FTO 365, 0 57 0.2 1.6x10 ¹¹ 0.4/0.43ms Comparative Example 4 MXene/ n -Si 405, 0 - 26.9x10 ^-3 - 0.84/1.67ms Comparative Example 5 ZnO-BiOCl/Ti ₃ C ₂ T _x //PDMS 350, 5 - 94.2x10 ^-6 5.86x10 ¹⁰ 2.59/0.93s Comparative Example 6 TI ₃ C ₂ T _x /NiO/TiO ₂ /FTO 365, 0 33 20x10 ^-3 4.1x10 ¹⁰ 80/130μs Example

As shown in Table 2, the MXene-based transparent solar cell 1 according to an embodiment of the present invention can implement a photoelectric device, and the photoelectric device is a photoelectric device that operates on its own in the absence of an external voltage or an external voltage. It may correspond to a photoelectric device whose characteristics are improved by application. Preferably, the photoelectric device has a detectability of 1.0x10 ¹⁰ to 9.9x10 ¹⁰ Jones under zero bias conditions, a reactivity of 1x10 ^-3 to 100x10 ^-3 AW ^-1 , a rise time (τ _r ) of 1 to 100 μs, and It may have a fall time (τ _f ) of 1 to 500 μs, and more preferably has a detectability of 4.1x10 ¹⁰ Jones, a reactivity of 20x10 ^-3 AW ^-1 , a rise time (τ _r ) of 80 μs, and a fall time of 130 μs. You can have (τ _f ).

The performance of the MXene-based transparent solar cell 1 as described above is superior to or equivalent to that of the plurality of comparative examples. The performance of the MXene-based transparent solar cell 1 as a photodetector may be achieved by the following factors.

(i) Due to the longitudinal structure of the MXene-based transparent solar cell (1), response speed is reduced by shortening the electrode gap.

(ii) Improved detection by reducing recombination of photogenerated charges due to built-in dislocations at the NiO/TiO ₂ interface and improving photogenerated charge collection.

(iii) Due to the excellent contact characteristics between MXene and NiO/TiO ₂ , the MXene-based transparent solar cell (1) can operate in solar cell mode, improving response speed.

The MXene-based transparent solar cell (1) can be implemented by directly integrating MXene into a large-scale transparent solar cell, which makes MXene suitable for application in highly scalable applications for invisible energy utilization and human electronics. It can be judged that it is.

In this way, in one embodiment of the present invention, the MXene-based transparent solar cell 1 can operate in a self-powered mode by inducing a high photovoltage, resulting in the effect of performing the role of a self-driving photodetector. It can be performed.

Hereinafter, a method for manufacturing an MXene-based transparent solar cell 1 according to an embodiment of the present invention will be described.

A method of manufacturing an MXene-based transparent solar cell (1) according to an embodiment of the present invention includes the steps of disposing a transparent substrate layer (100); Disposing a first transparent electrode layer 200 including FTO on the transparent substrate layer 100; Disposing an n-type oxide layer 300 containing TiO ₂ on the transparent electrode layer; Disposing a p-type oxide layer 400 containing NiO on the n-type oxide layer 300; and disposing a second transparent electrode layer 500 containing a two-dimensional nanomaterial on the p-type oxide layer 400, wherein the two-dimensional nanomaterial may include MXene.

In the step of disposing the transparent substrate layer 100 and the step of disposing the first transparent electrode layer 200, the transparent substrate layer 100 with the first transparent electrode layer 200 formed on the upper surface may be disposed.

The transparent substrate layer 100 (735159, Aldrich, sheet resistance = 7Ω/□) on which the first transparent electrode layer 200 is formed on the upper surface is sonicated with acetone, methanol and deionized water for 10 minutes, and then dried under a nitrogen atmosphere. It can be placed like this.

In the step of disposing the n-type oxide layer 300, a Ti target (iTASCO, purity 99.99%) is used, a deposition temperature of 1 to 1000 ° C., an argon (Ar) flow rate of 1 to 100 sccm, and oxygen of 1 to 50 sccm. The n-type oxide layer 300 can be formed through reactive sputtering (SNTEK, Korea) for 1 to 5 hours under the conditions of (O ₂ ) flow rate, DC power of 1 to 1000 W, and operating pressure of 1 to 100 mTorr.

Preferably, the n-type oxide layer 300 uses a Ti target, a deposition temperature of 500°C, an argon (Ar) flow rate of 50 sccm, an oxygen (O ₂ ) flow rate of 2.5 sccm, a DC power of 300W, and 5mTorr. It can be formed through reactive sputtering for 2 hours under conditions of operating pressure.

In the step of disposing the p-type oxide layer 400, in order to form a heterojunction structure with the n-type oxide layer 300, a Ni target (iTASCO, purity 99.99%) is used, and 1 to 100 sccm of argon ( Ar) p-type oxide layer through reactive sputtering (SNTEK, Korea) for 1 to 60 minutes under the conditions of an oxygen (O ₂ ) flow rate of 1 to 50 sccm, a DC power of 1 to 1000 W, and an operating pressure of 1 to 100 mTorr. (400) can be formed.

Preferably, the p-type oxide layer 400 uses a Ni target, and is formed at a temperature of 10 mTorr under the conditions of an argon (Ar) flow rate of 20 sccm, an oxygen (O ₂ ) flow rate of 5 sccm, a DC power of 50 W, and an operating pressure of 3 mTorr. Can be formed through reactive sputtering for minutes.

In addition, in the step of disposing the p-type oxide layer 400, before injecting the sputtering gas containing argon and oxygen to form the p-type oxide layer 400, a basic pressure of 1 to 100x10 ^-6 mTorr, and It is preferable to first perform pre-sputtering for 1 to 60 minutes under the condition of a rotation speed of 1 to 100 rpm, through which uniformity of the p-type oxide layer 400 can be secured.

Preferably, in the step of disposing the p-type oxide layer 400, pre-sputtering may first be performed for 10 minutes under the conditions of a basic pressure of 5x10 ^-6 mTorr and a rotation speed of 5 rpm before injecting the sputtering gas. there is.

In the step of disposing the second transparent electrode layer 500, a bare material is first formed and TFA treated, and then the second transparent electrode layer 500 can be formed by spin coating.

More specifically, in the step of disposing _{the second} transparent electrode layer 500 _, Bare Ti ₃ C ₂ T A TFA-treated Ti ₃ C ₂ T _x MXene solution was synthesized by treating _x MXene with TFA in distilled water at 0°C according to a known method. The TFA-treated Ti ₃ C ₂ T _x MXene solution can be formed by spin coating and then dried using a hot plate at 100°C to form the second transparent electrode layer 500.

The modified minimally concentrated layer stripping method uses a 12M LiF (98.5%, Acros)/9M HCl (diluted in 37% HCl solution) etchant to remove the Ti ₃ AlC ₂ MAX phase precursor (≥98.0%, It corresponds to a method of selectively etching the Al layer from the particle size ≤ 20 μm.

In the present invention, the conductivity and optical transparency of MXene were controlled by adjusting the number of coatings of the TFA-treated Ti ₃ C ₂ T _x MXene solution.

Preferably, the second transparent electrode layer 500 according to an embodiment of the present invention is formed by spin coating the TFA-treated Ti ₃ C ₂ T _x MXene solution on the p-type oxide layer 400 and then drying it. It can be. More preferably, the TFA-treated Ti ₃ C ₂ T _x MXene solution may be coated with a number of coatings selected from the range of 4 to 8.

According to one embodiment of the present invention, an MXene-based transparent solar cell is provided that uses MXene, a two-dimensional nanomaterial, as a front electrode to secure the transmittance of the transparent solar cell and easily collect light-generated carriers to effectively produce power. can be provided.

According to one embodiment of the present invention, the optical properties and electrical properties of an MXene-based transparent solar cell are improved by controlling the number of spin coatings of the TFA-treated Ti ₃ C _{2 T} It can have the effect of improving characteristics.

In one embodiment of the present invention, power can be produced from ultraviolet rays while selectively passing visible light by lowering the sheet resistance of MXene and improving the contact between MXene and p-NiO/n-TiO ₂ heterojunction.

According to one embodiment of the present invention, an MXene-based transparent solar cell includes a p-NiO/n-TiO ₂ heterojunction structure, thereby achieving the effect of spontaneously forming a built-in potential and converting incident photon energy into power. It can be performed.

According to one embodiment of the present invention, an MXene-based transparent solar cell can operate in a self-powered mode by inducing a high photovoltage, thereby demonstrating the effect of performing the role of a self-driving photodetector.

According to one embodiment of the present invention, the MXene-based transparent solar cell can obtain a fast optical response in self-powered mode, enabling self-supporting photovoltaic cells.

According to one embodiment of the present invention, MXene-based transparent solar cells have white light or color coordinates similar to sunlight, and may be suitable for application to windows of buildings and vehicles as an on-site power supply system.

As described above, although the embodiments have been described with limited examples and drawings, various modifications and variations can be made by those skilled in the art from the above description. For example, the described techniques are performed in a different order than the described method, and/or components of the described system, structure, device, circuit, etc. are combined or combined in a different form than the described method, or other components are used. Alternatively, appropriate results may be achieved even if substituted or substituted by an equivalent. Therefore, other implementations, other embodiments, and equivalents of the claims also fall within the scope of the claims described below.

1: MXene-based transparent solar cell
100: transparent substrate layer 200: first transparent electrode layer
300: n-type oxide layer 400: p-type oxide layer
500: Second transparent electrode layer

Claims (8)

As an MXene-based transparent solar cell,
Transparent substrate layer;
a first transparent electrode layer disposed on the transparent substrate layer and including FTO;
an n-type oxide layer disposed on the transparent electrode layer and containing TiO ₂ ;
a p-type oxide layer disposed on the n-type oxide layer and including NiO; and
A second transparent electrode layer disposed on the p-type oxide layer and containing a two-dimensional nanomaterial,
The 2D nanomaterial is an MXene-based transparent solar cell containing MXene.
In claim 1,
The two-dimensional nanomaterial is an MXene-based transparent solar cell containing a TFA-treated Ti ₃ C ₂ T _x MXene solution.
In claim 2,
The second transparent electrode layer is an MXene-based transparent solar cell that can be formed by spin coating the TFA-treated Ti ₃ C ₂ T _x MXene solution on the p-type oxide layer and then drying it.
In claim 1,
The MXene-based transparent solar cell can implement a photovoltaic device,
The photoelectric device is a photoelectric device that operates on its own in the absence of external voltage or a photoelectric device that improves characteristics by applying an external voltage. An MXene-based transparent solar cell.
In claim 1,
The MXene-based transparent solar cell,
An MXene-based transparent solar cell comprising an n-TiO ₂ /p-NiO heterojunction structure formed by the n-type oxide layer and the p-type oxide layer.
As a method of manufacturing an MXene-based transparent solar cell,
Disposing a transparent substrate layer;
disposing a first transparent electrode layer including FTO on the transparent substrate layer;
Disposing an n-type oxide layer containing TiO ₂ on the transparent electrode layer;
Disposing a p-type oxide layer containing NiO on the n-type oxide layer; and
Comprising: disposing a second transparent electrode layer containing a two-dimensional nanomaterial on the p-type oxide layer,
A method of manufacturing an MXene-based transparent solar cell, wherein the two-dimensional nanomaterial includes MXene.
In claim 6,
The two-dimensional nanomaterial is a method of manufacturing an MXene-based transparent solar cell, including a TFA-treated Ti ₃ C ₂ T _x MXene solution.
In claim 6,
The MXene-based transparent solar cell,
A method of manufacturing an MXene-based transparent solar cell, including an n-TiO ₂ /p-NiO heterojunction structure formed by the n-type oxide layer and the p-type oxide layer.