TW201735258A - Electronic device including graphene-based layer(s), and/or method of making the same - Google Patents

Abstract

Certain example embodiments of this invention relate to the use of graphene as a transparent conductive coating (TCC). In certain example embodiments, graphene thin films grown on large areas hetero-epitaxially, e.g., on a catalyst thin film, from a hydrocarbon gas (such as, for example, C2H2, CH4, or the like). The graphene thin films of certain example embodiments may be doped or undoped. In certain example embodiments, graphene thin films, once formed, may be lifted off of their carrier substrates and transferred to receiving substrates, e.g., for inclusion in an intermediate or final product. Graphene grown, lifted, and transferred in this way may exhibit low sheet resistances (e.g., less than 150 ohms/square and lower when doped) and high transmission values (e.g., at least in the visible and infrared spectra).

Description

Electronic device including graphene bottom layer and manufacturing method thereof

Certain exemplary embodiments of the invention relate to films comprising graphene. More particularly, certain exemplary embodiments of the invention relate to the use of graphene as a transparent conductive coating (TCC). In certain exemplary embodiments, the graphene thin film made of a hydrocarbon gas (such as, for example, C ₂ H _2, CH _4, etc.) over a large area, for example, a hetero-epitaxially grown on the catalyst film. The graphene film of certain exemplary embodiments may be doped or undoped. In certain exemplary embodiments, the graphene film, once formed, may be exfoliated from its carrier substrate and transferred to a receiving substrate, for example, contained in an intermediate or final product.

Indium tin oxide (ITO) and fluorine-doped tin oxide (FTO or SnO:F) coatings are widely used as window electrodes in photovoltaic devices. These transparent conductive oxides (TCOs) have been extremely successful in a variety of applications. However, unfortunately, the use of ITO and FTO is increasingly problematic for a number of reasons. Such problems include, for example, the fact that the amount of indium elements on the earth is limited, the instability of TCOs in the presence of an acid or base, and the diffusion of ions in the ion-conducting layer, which are in the near-infrared region (eg, high power spectrum). Limited transparency, high leakage current of FTO devices caused by FTO structural defects, and so on. The embrittlement properties of ITO and its high deposition temperature may also limit its application. In addition, surface roughness in SnO ₂ :F may cause problematic arcing.

Accordingly, it will be appreciated that there is a need in the art for smooth and patternable electrode materials having good stability, high transparency, and excellent electrical conductivity.

Research on novel electrode materials with good stability, high transparency, and excellent electrical conductivity is underway. One aspect of this study includes identifying viable alternatives to these conventional TCOs. In this regard, the inventors of the present invention have developed a viable transparent conductive coating (TCC) based on carbon, especially graphene.

The term graphene generally refers to graphite having one or more atomic layers, for example, having a single graphene layer or an SGL that can extend up to n layers of graphite (eg, n can be as high as 10). The recent discovery and separation of graphene at the University of Manchester (by stripping crystalline graphite) coincides with the trend of electronic components to reduce the size of circuit components to the nanometer level. On the one hand, graphene has unexpectedly led to a new world of unique optoelectronic properties that are not encountered in standard electronic materials. This occurs in a linear dispersion relationship (E vs. k) such that the charge carriers in graphene have zero static mass and behave as relativistic particles. This type of relative behavior of non-localized electrons moving around carbon atoms is caused by the interaction of their periodic potential with the honeycomb lattice of graphene, resulting in new quasiparticles at low energy (E < 1.2 eV). 2+1)-Vedillac equation with a v _F An effective speed of light of c/300 = 10 ⁶ ms- ¹ is accurately depicted. Therefore, the widely accepted quantum electrodynamic (QED) technique (processing photons) can be applied to graphene research - another advantageous aspect is that these effects are amplified by a factor of 300 in graphene. For example, the universal coupling constant α is close to 2 in graphene compared to 1/137 of vacuum. See KSNovoselov, "Electrical Field Effect in Atomically Thin Carbon Films", Science, Vol. 306, pp. 666-69 (2004), the contents of which is incorporated herein by reference.

Although only one atom thick (minimum), graphene is chemically and thermally stable (although graphene can be surface oxidized at 300 degrees Celsius), allowing the successful fabrication of graphene substrate devices to withstand ambient conditions. High quality graphene sheets were first fabricated by micromechanical stripping of bulk graphite. The same technique can be adjusted to provide high quality graphene crystals up to 100 μm ² in size today. This size is sufficient for most of the research purposes in microelectronics. Therefore, most of the technology that has been developed so far in universities is focused on microscopic samples, device preparation and characterization, rather than increase.

Unlike most current research trends, in order to achieve the maximum potential of graphene as a suitable TCC, large-area deposition of high quality materials on substrates such as glass or plastic substrates is necessary. To date, most large-scale graphene production processes have relied on the use of block-like graphite stripping of wet-based chemicals, beginning with high-order pyrolytic graphite (HOPG) and chemical spalling. It is well known that HOPG is in the form of high-order pyrolytic graphite with a c-axis angular spread of less than 1 degree and is typically produced by stress annealing of 3300K. HOPG behaves more like a pure metal because it is generally reflective and conductive, although brittle and flaked. The graphene produced in this way is filtered and then adhered to a watch surface. However, there are disadvantages in this stripping procedure. For example, exfoliated graphene is easily overlapped and crumpled, exists in the form of strips, and is deposited by a splicing/stitching procedure, lacking internal control over the number of graphene layers, and the like. The materials so produced are usually contaminated by the interlayer and, in this respect, have low-level electronic properties.

Depth analysis of a carbon phase diagram shows that the program window conditions are not only suitable for the production of graphite and diamond, but also for the production of other allotropic forms such as, for example, carbon nanotubes (CNT). The catalyst deposition of the nanotubes can be accomplished in a variety of different groups from a gas phase at temperatures up to 1000 degrees Celsius.

In contrast to such conventional research fields and conventional techniques, certain exemplary embodiments of the present invention relate to an expandable technique for heterogeneous epitaxial growth of single crystal graphite (n is approximately 15) and convert it to high Electronic grade (HEG) graphene (n < about 3). Certain exemplary embodiments are also directed to the use of HEG graphene in transparent (in the visible and infrared spectrum), electrically conductive ultra-thin graphene films, for example, as common for various applications including, for example, solid state solar cells. A replacement for metal oxide window electrodes. The growth techniques of certain exemplary embodiments are based on a catalyst driven heteroepitaxial CVD process that occurs at a sufficiently low temperature suitable for the glass. For example, thermodynamic and kinetic principles allow HEG graphene films to be crystallized from a gas phase on a catalyst layer at a temperature below about 700 degrees Celsius.

Certain exemplary embodiments also use atomic hydrogen, which has proven to be an effective free radical for removing amorphous carbonaceous contamination on a substrate and capable of being implemented at low processing temperatures. It is also good at removing oxides and other coatings typically left by the etching step.

Certain exemplary embodiments are directed to a solar cell. The solar cell comprises a glass substrate. A first graphene substrate conductive layer is disposed directly or indirectly on the glass substrate. A first semiconductor layer is in contact with the first graphene substrate conductive layer. At least one absorber layer is disposed directly or indirectly over the first semiconductor layer. A second semiconductor layer is disposed directly or indirectly on the at least one absorber layer. A second graphene substrate conductive layer is in contact with the second semiconductor layer. A back contact is disposed directly or indirectly on the second graphene substrate conductive layer.

In some exemplary embodiments, the first semiconductor layer is an n-type semiconductor layer, and the first graphene bottom layer is doped with an n-type dopant, and the second semiconductor layer is a p-type semiconductor layer, and the second graphite The base layer is doped with a p-type dopant. In certain exemplary embodiments, a layer of zinc-doped titanium oxide is interposed between the glass substrate and the first graphene-based underlayer. In certain exemplary embodiments, the first and/or second semiconductor layers may comprise a polymeric material.

Certain exemplary embodiments are directed to a photovoltaic device. The photovoltaic device comprises a substrate, at least one photovoltaic film layer; first and second electrodes; and first and second transparent, conductive graphene ground layers. The first and second graphene-based underlayers are doped with n-type and p-type dopants, respectively.

Certain exemplary embodiments pertain to a touch panel subassembly. The touch panel subassembly includes a glass substrate. A first transparent, conductive graphene-based underlayer is provided directly or indirectly on the glass substrate. A deformable foil is provided that is substantially parallel to and spaced from the glass substrate. A second transparent, electrically conductive graphene-based underlayer is provided directly or indirectly on the deformable foil.

In certain exemplary embodiments, the first and/or second graphene-based underlayers are patterned. In certain exemplary embodiments, a plurality of posts may be disposed between the deformable foil and the glass substrate, and at least one side seal may be provided at the periphery of the subassembly.

Certain exemplary embodiments are directed to a touch panel device that includes a touch panel subassembly. A display can be coupled to a surface of the substrate of the touch panel subassembly opposite the deformable foil. In some exemplary embodiments the touch panel device can be a capacitive or resistive touch panel device.

Some exemplary embodiments pertain to a data/bus bar comprising a graphene-based underlayer supported by a substrate. A portion of the graphene-based underlayer is exposed to an ion beam/plasma treatment and/or etched with H* to reduce the conductivity of the portion. In certain exemplary embodiments, the portion is non-conductive. In certain exemplary embodiments, the substrate is a glass substrate, a germanium wafer, or other substrate. In certain exemplary embodiments, the portion can be at least partially removed by exposure to ion beam/plasma processing and/or H* etching.

Certain exemplary embodiments are directed to an antenna. A graphene-based underlayer is supported by a substrate. A portion of the graphene-based underlayer has been exposed to an ion beam/plasma treatment and/or etched with H* to thin the portion of the graphene-based underlayer relative to other portions of the graphene-based underlayer . The graphene-based underlayer as a whole has a visible light transmission of at least 80%, preferably at least 90%.

Certain exemplary embodiments are directed to a method of making an electronic device. A substrate is provided. A graphene-based underlayer is formed on the substrate. The graphene-based underlayer is selectively patterned by one of: Ion beam/plasma exposure and H* etching.

In certain exemplary embodiments, the graphene-based underlayer is transferred to a second substrate prior to patterning. In certain exemplary embodiments, patterning is performed to reduce the conductivity of the graphene-based underlayer and/or remove a portion of the graphene-based underlayer.

The features, aspects, advantages, and exemplary embodiments described herein may be combined to implement further embodiments.

S101~S107, S301~S307, S401~S405, S1002~S1050, S1401~S1407‧‧‧ steps

501‧‧‧ hydrocarbon gas

503‧‧‧(metal) catalyst layer

503'‧‧‧ catalyst layer

505‧‧‧ Rear bracket/stacked coated substrate

507‧‧‧Solid dopants

509‧‧‧(doped) graphene

701‧‧‧ release layer

703‧‧‧ polymer layer

801‧‧‧ target substrate

803a‧‧‧Upper roll

803b‧‧‧ lower roll

901‧‧‧ Subject (partial)

903‧‧‧air inlet

905‧‧‧Exhaust port

907‧‧‧ shower head

909‧‧‧Back support substrate

913‧‧‧ coolant inlet/outlet

1202‧‧‧ glass substrate

1204‧‧‧Anti-reflective (AR) coating

1206‧‧‧Absorbent layer

1208‧‧‧(n-type) semiconductor (layer)

1210‧‧‧(p-type) semiconductor (layer)

1212‧‧‧Back contact

1214, 1314‧‧ (first) graphene-based underlayer

1216, 1316‧‧‧ (second) graphene-based underlayer

1218‧‧‧Selective layer

1302‧‧‧Lower display

1304‧‧‧Optical transparent adhesive

1306‧‧‧thin glass

1308‧‧‧PET foil

1310‧‧‧ Column spacing

1312‧‧‧ side seal

HC‧‧‧ vertex interval

R‧‧ Direction

These and other features and advantages may be further and more fully understood from the following detailed description of exemplary embodiments in conjunction with the drawings. FIG. 1 is a high-level flow diagram showing one of the general techniques of certain exemplary embodiments. 2 is an exemplary schematic diagram of a catalyst growth technique of certain exemplary embodiments illustrating hydrocarbon gas introduction, carbon dissolution, and possible quenching results in accordance with certain exemplary embodiments; FIG. 3 is a diagram illustrating Embodiments, a flow chart of a first exemplary technique for doping graphene; FIG. 4 is a flow chart illustrating a second exemplary technique for doping graphene, in accordance with certain exemplary embodiments; A flow diagram of a third exemplary technique for doping graphene in accordance with certain exemplary embodiments; FIG. 6 is a graph depicting temperature versus time in graphene doping, in accordance with certain exemplary embodiments; 7 is an exemplary layer stack that may be utilized in graphene release and de-splitting techniques of certain exemplary embodiments; FIG. 8 is a diagram of graphene that may be used to dispose a target glass substrate in accordance with certain exemplary embodiments. FIG. 9 is a schematic cross-sectional view of a reactor suitable for depositing high electron level (HEG) graphene according to an exemplary embodiment; FIG. 10 is a schematic diagram showing a certain catalyst CVD growth, spalling And an exemplary program flow diagram of a transfer technique of certain exemplary embodiments; FIG. 11 is an image of the same graphene produced in accordance with certain exemplary embodiments; and FIG. 12 is a graphene-containing substrate in accordance with certain exemplary embodiments. A schematic cross-sectional view of a solar photovoltaic device of a layer; FIG. 13 is a schematic cross-sectional view of a touch screen comprising a graphene-based underlayer, in accordance with certain exemplary embodiments; and FIG. 14 is used to form a conductive device in accordance with certain exemplary embodiments. A flowchart of an exemplary technique for data/busbars; and FIG. 15 is a schematic diagram of a technique for forming a conductive data/busbar in accordance with certain exemplary embodiments.

Certain exemplary embodiments of the present invention are directed to a scalable technique for heteroepitaxially growing single crystal graphite (n is about 15) and converting it to high electron level (HEG) graphene (n < about 3). Certain exemplary embodiments are also directed to the use of HEG graphene in transparent (in the visible and infrared spectrum), electrically conductive ultra-thin graphene films, for example, for various applications (including, for example, Solid-state solar cells are a common alternative to metal oxide window electrodes. The growth techniques of certain exemplary embodiments are based on a catalyst driven heteroepitaxial CVD process that occurs at a sufficiently low temperature suitable for the glass. For example, thermodynamic and kinetic principles allow HEG graphene films to be crystallized from the gas phase in a catalyst layer (eg, at a temperature of less than about 600 degrees Celsius).

1 is a high level flow chart showing the general technique of certain exemplary embodiments. As shown in Figure 1, the general techniques of certain exemplary embodiments can be classified into one of four basic steps: crystallization of graphene on a suitable rear support (step S101), release of graphene from the rear support Or splitting (step S103), the graphene migrates to the target substrate or surface (step S105), and the target substrate or surface is incorporated into a product (step S107). As will be described in more detail below, it will be appreciated that the product proposed in step S107 can be an intermediate product or a final product.

Demonstration of graphene crystallization technology

The graphene crystallization technique of certain exemplary embodiments can be considered to include "cracking" a hydrocarbon gas and recombining carbon atoms into a familiar honeycomb structure over a large area (e.g., an area of about 1 meter or more). For example, leverage uses a surface catalyst path. The graphene crystallization techniques of certain exemplary embodiments occur at high temperatures and moderate pressures. Illustrative details of this demonstration procedure are described in detail below.

The catalyst growth technique of certain exemplary embodiments is somewhat directed to techniques used to grow graphite on a heteroepitaxial epitaxial area. A catalyst for graphene crystals is disposed on a suitable rear support. The rear bracket can be any material that is resistant to high heat (eg, temperatures up to about 1000 degrees Celsius) Materials such as, for example, certain ceramic or glass products, zirconium containing materials, aluminum nitride materials, tantalum wafers, and the like. A film is placed directly or indirectly on the rear support, thereby ensuring that its surface is substantially uncontaminated prior to the crystallization process. The inventors of the present invention have found that graphene crystals are promoted when the catalyst layer has a substantially unidirectional crystal structure. In this regard, small grains are determined to be less advantageous because their damascene structure will eventually be transferred to the graphene layer. In any case, if the catalyst layer has a unidirectional crystal structure at least in substantial portions, the specific orientation of the crystal structure has been found to be largely unimportant for graphene crystals. In fact, the relative lack of grain boundaries or low grain boundaries in the catalyst has been found to result in the growth of graphene in the same or similar direction and was found to provide high electronic grade (HEG) graphene.

The catalyst layer itself can be disposed on the rear support by any suitable technique, such as, for example, sputtering, combustion vapor deposition (CVD), flame pyrolysis, and the like. The catalyst layer itself may comprise any suitable metal or metal containing material. For example, the catalyst layer can comprise, for example, a metal such as nickel, cobalt, iron, a high permeability alloy (eg, a nickel-iron alloy, generally comprising about 20% iron and 80% nickel), nickel and chromium, copper, and combinations thereof. Alloy. Of course, other metals can be used in certain exemplary embodiments. The inventors have found that a nickel catalyst layer or a catalyst layer comprising nickel is particularly advantageous for graphene crystallization, and a nickel-chromium alloy is more advantageous. Additionally, the inventors have discovered that the amount of chromium in the nickel chrome layer (sometimes referred to as the nickel chrome or NiCr layer) can be optimized to promote the formation of large crystals. In particular, 3-15% of chromium in the NiCr layer is preferred, and 5-12% of chromium in the NiCr layer is more preferable, and 7-10% of chromium in the NiCr layer is more preferable. The presence of vanadium in the metal film has also been found to be beneficial for promoting large crystal growth. Catalyst layer To thin or thick. For example, the film may be 50-1000 nm thick, preferably 75-750 nm thick, and more preferably 100-500 nm thick. In some demonstrations, a "large crystal growth" includes a crystal having a length on the order of tens of microns along a major axis, and sometimes larger.

Once the catalyst film is disposed on the rear support, a hydrocarbon gas (for example, C ₂ H ₂ gas, CH ₄ gas, etc.) is introduced into a chamber, and a rear support on which the catalyst film is disposed is placed In the room. The hydrocarbon gas can be introduced from a pressure in the range of from about 5 to 150 mTorr, preferably from 10 to 100 mTorr. In general, the greater the pressure, the faster the graphene grows. The rear brace and/or the chamber as a whole are further heated to dissolve or "crack" the hydrocarbon gas. For example, the rear bracket can be raised to a temperature in the range of 600-1200 degrees Celsius, preferably 700-1000 degrees Celsius, and more preferably 800-900 degrees Celsius. Heating can be accomplished by any suitable technique, such as, for example, via a short wave infrared (IR) heater. Antipyretic can occur in an environment comprising a gas, such as a mixture of argon, nitrogen, nitrogen and hydrogen, or other suitable environment. In other words, in certain exemplary embodiments, hydrocarbon gas heating can occur in an environment that includes other gases. In certain exemplary embodiments, it may be necessary to use a pure hydrocarbon gas (e.g., using C ₂ H _2), and may further require the use of hydrocarbon gas and an inert gas or other gases (e.g., Ar, mixed with CH _4).

The graphene will grow in this or another suitable environment. In order to stop growth and help ensure that graphene grows on the catalyst surface (e.g., as opposed to being embedded in a catalyst), certain exemplary embodiments utilize a quenching procedure. Quenching can be performed using an inert gas such as, for example, argon, nitrogen, combinations thereof, and the like. In order to promote the growth of graphene on the surface of the catalyst layer, quenching The fire should be executed fairly quickly. More specifically, it has been found that quenching too quickly or too slowly results in poor or no graphene on the surface of the catalyst layer. In general, quenching has been found to promote good growth of graphene, for example via chemisorption, to reduce the temperature of the back bracing and/or substrate from about 900 degrees Celsius to 700 degrees Celsius (or lower) over a period of minutes. In this regard, FIG. 2 is an exemplary schematic of a catalyst growth technique of certain exemplary embodiments illustrating the introduction of hydrocarbon gas, carbon dissolution, and possible results of quenching.

The graphene growth procedure utilizes a precise thickness relationship t = n x SLG, where n includes some discrete number of steps. It is extremely rapid to identify whether graphene has been produced and to determine that the n value on the membrane area is approximately equal to the film quality and uniformity measured in a single measurement. Although graphene sheets can be seen with atomic force and scanning electron microscopy, such techniques are time consuming and can also cause graphene contamination. Accordingly, certain exemplary embodiments utilize a phase contrast technique that increases the visibility of graphene on a predetermined catalyst surface. This can be done for the purpose of mapping any change in the value of n to the deposition surface on the metal catalyst film. This technique relies on the fact that the contrast of graphene can be enhanced by spin coating a material onto it. For example, a widely used UV curable resist (eg, PMMA) can be spin coated, screen printed, recessed, or disposed on a graphene/metal/back bracket, for example, in a manner sufficient to make the film visible and continuous. The thickness (for example, about 1 micron) is the same. As described in more detail below, the inclusion of a polymeric resist also promotes the exfoliation procedure of graphene prior to its transfer to the final surface. That is, in addition to providing an indication as to when the formation of graphene is completed, the polymer resist may also be provided when the metal layer is released or cracked from the rear support as described below. A support for highly elastic graphene.

If a layer grows too thick (intentionally or unintentionally), the layer can be etched, for example, using a hydrogen atom (H*). This technique may be advantageous in many exemplary situations. For example, H* can be used to correct such problems when growth occurs too quickly, unexpectedly, unevenly, and the like. As another example, to ensure sufficient graphene growth, graphite can be produced, graphane can be deposited, and graphane can be selectively etched back to the desired n-scale HEG graphene using, for example, H*. As another example, H* can be used to selectively etch graphene, for example, to create conductive areas and non-conductive areas. This can be done by, for example, applying a mask, performing etching and then removing the mask.

Theoretical studies of graphene show that the mobility of the carrier is higher than 200,000 cm ² /(V ‧ s). The experimental measurement of gas phase treatment of heterogeneous epitaxial growth of graphene showed a resistivity of 3 × 10 ⁶ lines-cm, which is superior to that of the silver film. The sheet resistance of these graphene layers has been found to be approximately 150 ohms/square. One factor that can be varied is the number of graphene layers required to provide the lowest resistivity and sheet resistance. Obviously, the desired graphene thickness can vary depending on the target application. In general, graphene suitable for most applications may be n = 1-15 graphene, preferably n = 1-5 graphene, and sometimes n = 2-3 graphene. An n=1 graphene layer has been found to result in a conduction decrease of approximately 2.3-2.6%. This reduction in transmission has been found to be substantially linear across the entire spectrum, such as from ultraviolet (UV), through visible light, and through IR. In addition, the loss in transmission has been found to be substantially linear with each successive increment of n.

Demonstration doping technique

Although a sheet resistance of 150 ohms/square may be suitable for some demonstrations The application will understand that a further reduction in sheet resistance may be required for different demonstration applications. For example, it will be appreciated that a sheet resistance of 10-20 ohms/square may be required for some exemplary applications. The inventors of the present invention have determined that the sheet resistance can be lowered via graphene doping.

In this regard, since only one atomic layer is thick, graphene shows direct transfer on the ultra-micron level, and at n In the case of 2, it can be heavily doped by the gate voltage or the molecule being adsorbed or inserted without significant loss of mobility. The inventors of the present invention have determined that in graphene, in addition to the donor/acceptor distinction, there are roughly two different classes of dopants, paramagnetic and non-magnetic. In contrast to conventional semiconductors, the latter type of impurities are generally used as weak dopants, while paramagnetic impurities result in strong doping. Since the linearity disappears, the electron-hole symmetric density (DOS) of the state near the Dirac point of graphene, and the local impurity state without spin polarization are set at the center of the virtual energy gap. Therefore, the impurity states in graphene are strongly distinguished from their counterparts in ordinary semiconductors, the DOS in the valence band and the conduction band are extremely different, and the impurity energy level is substantially away from the middle of the energy gap. Although it may not be desirable to have a strong doping effect that defines the presence of the donor (or acceptor) energy level from the Fermi level tens of electron volts, if the impurity has a local magnetic moment, its energy level is on the order of 1 eV. The Hund exchange is almost symmetrically separated, and the Hundred exchange is an advantageous case for providing a highly doped impurity effect on a two-dimensional system electronic structure such as a Dirac spectrum present in graphene. This line of reasoning can be used to guide the selection of molecules that form paramagnetic monomolecular and diamagnetic dimer systems for doping graphene and increase its conductivity from 10 ³ S/cm to 10 ⁵ S/cm. And sometimes even up to 10 ⁶ S/cm.

Exemplary dopants suitable for use in certain exemplary embodiments These include nitrogen, boron, phosphorus, fluoride, lithium, potassium, ammonium, and the like. Sulfur-based dopants (e.g., sulfur dioxide) can also be used in certain exemplary embodiments. For example, sulfides present in the glass substrate can be caused to bleed out of the glass, and thus doped with a graphene-based underlayer. Several exemplary graphene doping techniques are set forth in more detail below.

3 is a flow chart showing a first exemplary technique for doping graphene, in accordance with certain exemplary embodiments. The exemplary technique of Figure 3 essentially includes implanting a metal-doped ion beam in graphene. In this exemplary technique, graphene is grown on a metal catalyst (step S301), for example as described above. The catalyst having the graphene formed thereon is exposed to a gas (sometimes referred to as a dopant gas) containing a material used as a dopant (step S303). A plasma is further excited in a chamber containing the catalyst and dopant gas on which the graphene is formed (S305). An ion beam is in turn used to implant the dopant into the graphene (S307). For example, ion beam techniques suitable for such doping are disclosed in, for example, U.S. Patent No. 6,602,371; U.S. Patent No. 6,808,606; and Reissue No. 38,358, and U.S. Publication No. 2008/0199702, each This case is incorporated herein by reference. The ion beam power can be from about 10 to 200 ev, preferably from 20 to 50 ev, more preferably from 20 to 40 ev.

4 is a flow chart showing a second exemplary technique for doping graphene, in accordance with certain exemplary embodiments. The exemplary technique of FIG. 4 essentially includes pre-implanting a solid dopant in a target receiving substrate, and in turn, moving the solid dopant into the graphene when the graphene is applied to the receiving substrate. In this exemplary technique, graphene is grown on a metal catalyst (steps) S401), for example, as described above. The receiving substrate is pre-fabricated to include a solid dopant therein (step S403). For example, a solid dopant can be included in a formulation that is included in the glass via melting. About 1-10% atoms, preferably 1-5% atoms, more preferably 2-3% atomic dopants may be included in the glass melt. Graphene is applied to the receiving substrate, for example, using one of the exemplary techniques detailed below (step 405). The solid dopant in the receiving substrate is then migrated into the graphene. The heat used for graphene deposition will cause the dopant to migrate toward the graphene layer being formed. Similarly, additional doped films can be included in the glass, and the dopants therein can be migrated through the layers by thermal diffusion, for example, to create a doped graphene layer (n >= 2).

In certain exemplary embodiments, an ion beam can also be used to implant dopants directly into the glass. The ion beam power may be from about 10 to 1000 ev, preferably from 20 to 500 ev, more preferably from 20 to 100 ev. When an intermediate layer is doped and used to provide impurities of graphene, the ion beam can be operated from about 10 to 200 ev, preferably from 20 to 50 ev, more preferably from 20 to 40 ev.

FIG. 5 is an exemplary schematic diagram of a third exemplary technique for doping graphene in accordance with certain exemplary embodiments. The exemplary technique of FIG. 5 essentially includes pre-implanting a solid dopant 507 in the metal catalyst layer 503, and further, when the graphene is formed, such solid dopants 507 are migrated via the catalyst layer 503, thus being in contact A doped graphene 509 is formed on the surface of the dielectric layer 503. More specifically, in this exemplary technique, the catalyst layer 503 is disposed on the rear bracket 505. The catalyst layer 503 includes a solid dopant 507 therein. In other words, the catalyst has solid dopant atoms within its bulk (eg, It is about 1-10%, preferably about 1-5%, and most preferably about 1-3%). The hydrocarbon gas 501 is introduced close to the catalyst layer 503 formed at a high temperature. The solid dopant 507 in the catalyst layer 503 occurs as the graphene crystallizes, for example by being transferred to its outer surface by high temperature. The rate at which the dopant reaches the surface has been found to be a function of the thickness and temperature of the catalyst layer. The crystallization is stopped by quenching, and finally, a doped graphene 509 is formed on the surface of the catalyst layer 503'. After the doped graphene 509 is formed, the catalyst layer 503' has less (or no) solid dopant 507 therein. One advantage of this exemplary technique is the possibility of controlling ultra-thin film growth by clearly changing the metal surface temperature, partial pressure, and residence time of the deposition gas species, as well as the active free radicals used in the quenching rate program.

It will be appreciated that such exemplary doping techniques can be used individually and/or in various combinations and sub-combinations and/or other techniques. It will also be appreciated that certain exemplary embodiments may comprise a single dopant material or multiple times by using a particular exemplary technique, using a particular technique multiple times, or by using one or more of a combination of multiple techniques. Dopant material. For example, p-type and n-type dopants are possible in certain exemplary embodiments.

6 is a graph depicting temperature versus time in graphene doping, in accordance with certain example embodiments. As indicated above, cooling can be accomplished using, for example, an inert gas. In general, and as also noted above, in certain exemplary embodiments, the elevated temperature may be approximately 900 degrees Celsius, and the low temperature may be approximately 700 degrees Celsius, and cooling may occur for a few minutes. The same heating/cooling pattern as shown in Figure 6 can be used regardless of whether graphene is doped.

Demonstration of graphene release/de-splitting and transfer technology

Once the graphene is heteroepitaxially grown, it can be released or de-cracked from the metal catalyst and/or the rear support, for example, before being placed on the substrate to be incorporated into the intermediate or final product. According to certain exemplary embodiments, various steps may be implemented to lift the epitaxial film from its growth substrate. 7 is an exemplary layer stack of graphene release or de-splitting techniques for certain exemplary embodiments. Referring to FIG. 7, in certain exemplary embodiments, a selective release layer 701 can be provided between the rear support 505 and the catalyst layer 503. Release layer 701 can be or include, for example, zinc oxide (eg, ZnO or other suitable stoichiometry). Post-graphene deposition, graphene 509 / metal catalyst layer 503 / release layer 701 stacked coating substrate 505 can receive a thick coating (eg, several microns thick) polymer layer 703, for example, via spin coating application, by A curved moon stream is dispensed, etc., which can be cured. As mentioned above indirectly, the polymer layer 703 can be used as one of the backbones or supports of the graphene 509 during spalling and/or cracking, maintaining the continuity of the extremely flexible graphene film while also reducing the roll of the graphene film, The prominence of wrinkles or deformation.

As also mentioned indirectly above, PMMA can be used as a polymer to make graphene visible by phase contrast and for support before and/or during exfoliation. However, a wide range of mechanically and chemically compatible polymers with graphene can be used during the support phase, as well as during the release of the transfer phase associated with certain exemplary embodiments. The spalling operation can be performed, for example, in parallel with the main epitaxial growth branch by a graphene film test which can be chemically peeled off by graphite.

The release layer can be chemically induced to cause the graphene/metal to be cleaved from the master once the polymer layer is disposed thereon. For example, in oxidation In the case of a zinc release layer, washing in vinegar can trigger the release of graphene. It is also advantageous to use a zinc oxide release layer since the inventors of the present invention have discovered that the metal catalyst layer is also removed from the graphene as a release layer. This is believed to be the result of structuring of the zinc oxide release layer along with its interconnection with the grains in the catalyst layer. It will be appreciated that this reduces (and sometimes even eliminates) the need to remove the catalyst layer later.

Some spalling/disbonding and transfer techniques essentially recognize the original substrate as a reusable epitaxial growth substrate. Thus, in such exemplary embodiments, a selective etch may be required to etch from the epitaxially grown (top with polymer) graphene to undermine and dissolve the metal catalyst film. Thus, in certain exemplary embodiments, the catalyst layer can be etched away regardless of whether a release layer is used. Suitable etchants include, for example, acids such as hydrochloric acid, phosphoric acid, and the like.

The surface of the final acceptor glass substrate can be prepared to receive the graphene layer. For example, a Langmuir Blodgett film (eg, from a Langmuir Blodgett acid) can be applied to the glass substrate. The final acceptor substrate may alternatively or additionally be coated with a smooth pro-graphene layer such as, for example, an amorphous germanium-based polymer or the like to enable the latter to receive graphene. This may help to ensure electrostatic bonding, thus preferentially allowing graphene transfer during transfer. The target substrate can be additionally or alternatively exposed to UV radiation to increase the surface energy of the target substrate and thus enable it to receive graphene.

In certain exemplary embodiments, graphene may be applied to a substrate via blanket coating and/or rolling. This procedure allows graphene to grow in advance, And it is chemically adsorbed to the metal carrier to be transferred to the acceptor glass by contact pressure. For example, graphene can be applied to the substrate via one or more laminating rolls, for example, as shown in FIG. In this regard, FIG. 8 illustrates the upper and lower rolls 803a and 803b which apply pressure and laminate the graphene 509 and polymer layer 703 to the target substrate 801. As noted above, the target substrate 801 has a containing or other graphene layer thereon to facilitate lamination. It will be appreciated that polymer layer 703 will be applied as the outermost layer and graphene 509 will be closer to (or directly above) target substrate 801. In certain exemplary embodiments, one or more layers may be provided on a substrate prior to application of the graphene.

Once the graphene is disposed on the target substrate, the polymer layer can be removed. In certain exemplary embodiments, the polymer can be dissolved using a suitable solvent. When a photosensitive material such as PMMA is used, it can be removed via UV light exposure. Of course, other removal techniques are also possible.

It will be appreciated that in certain exemplary embodiments, the catalyst film can be etched away after the graphene is applied to the target substrate, for example using one of the exemplary etchants described above. The choice of etchant can also be based on the presence or absence of any layer under the graphene.

Some exemplary embodiments are more electrochemically electroplating a metal catalyst film under graphene. In these exemplary embodiments, graphene itself can be used as a cathode while the underlying metal is electroplated onto a transparent oxide while still being bonded to the original substrate. Such exemplary embodiments can be used to circumvent the use of a polymeric coating by performing a spalling and transfer procedure in substantially one step. However, electrochemical plating can affect the electronic properties of graphene and thus may need to be compensated. In certain exemplary embodiments, graphene The underlying catalyst layer can be oxidized in other ways to make it transparent. For example, a conductive oxide can be used to "link" a graphene-based underlayer to a substrate, semiconductor or other layer. In this regard, cobalt, chrome cobalt, nickel chrome cobalt, and/or the like may be oxidized. In certain exemplary embodiments, this also reduces the need for graphene flaking, making transfer, handling, and other processing of graphene easier.

In certain exemplary embodiments, graphene may also be picked up using a binder or ribbon material. The adhesive can be placed on the target substrate. The graphene can be transferred to the target substrate, for example, by applying a pressure to the substrate by bonding to the substrate more strongly.

Demonstration reactor design

Showerhead reactors typically employ a perforated or porous plane to distribute the reactant gases almost uniformly over a second parallel heating plane. This structure can be used to grow graphene using the exemplary heterogeneous epitaxial technique described above. The showerhead reactor also facilitates the processing of large square ultra-smooth glass or ceramic substrates. A basic schematic of a showerhead reactor is Figure 9, and the inflatable design is enlarged. In other words, Figure 9 is a schematic cross-sectional view of a reactor suitable for depositing high electron level (HEG) graphene, in accordance with an exemplary embodiment. The reactor includes a body portion 901 having a plurality of inlets and outlets. More specifically, an air inlet 903 is provided at the top and at approximately the horizontal center of the reactor body 901. The gas inlet 903 can receive gases from one or more sources, and thus can provide various gases including, for example, hydrocarbon gases, gases used to form the environment during heterogeneous epitaxial growth, quenching gases, and the like. The gas flux and flow rate will be detailed, for example, with reference to the inflatable design of the showerhead 907. A plurality of exhaust ports 905 may be provided at the bottom of the reactor body 901. Demonstrate implementation in Figure 9. In the example, two vents 905 are provided proximate the end of the reactor body 901 to, for example, extract gas that is provided by the inlet 903 and that will generally flow through substantially the entire body 901. It will be appreciated that in certain exemplary embodiments, more or less vents 905 may be provided (eg, additional vents 905 may be provided at approximately the horizontal center of reactor body 901, in reactor body 901 The top or sides, etc.).

In certain exemplary embodiments, the back support substrate 909 can be cleaned by a vacuum lock mechanism prior to entering the reactor with a catalyst film disposed thereon (eg, by physical vapor deposition or PVD, sputtering) , flame pyrolysis, etc.). In terms of pedestal design, the surface of the back support substrate 909 can be rapidly heated (eg, using an RTA heater, a short-wave IR heater, or other layer capable of inductively heating the substrate and/or thereon without the need for Also heating the appropriate heater of the entire chamber to a controlled temperature level and allowing for consistency of (i) metal film crystallization and activation, and (ii) substantially uniform and controllable thickness of graphene from a gas phase The preferred deposition of the parent metal on its surface. The heater can be controllable to result in a parameter deposition rate / catalyst (temperature * thickness) ratio. The back support substrate 909 can move through the reactor in the direction R or can remain stable under the shower head 907. The showerhead 907 can be cooled, for example, using a cooling fluid or gas introduced by one or more coolant inlets/outlets 913. Briefly, and as shown in the enlarged view of Figure 9, the inflatable design can include a plurality of holes at the bottom of the showerhead 907, each of which is only a few millimeters wide.

Changing the vertex spacing Hc, or the height between the bottom surface of the showerhead 907 and the top surface on which the backing substrate 909 moves, may have several effects. For example, the chamber volume and hence the surface to volume ratio can be modified, thus Gas retention time, time consuming, and radial velocity. The change in residence time has been found to strongly influence the extent of the gas phase reaction. A showerhead structure (having a hot surface under a cooling surface) operating as shown in Figure 9 has the possibility of natural convection with Bernard's variation if operated at high pressure (e.g., in the hundreds of milliTorr), and this trend is through The number (the number of non-causes associated with buoyancy-driven flow, also known as free convection or natural convection, when it exceeds a critical value for a fluid, the heat transfer is predominantly in the form of convection) is strongly influenced by altitude. Therefore, the apex spacing Hc can be varied by simple hardware changes by providing an adjustable mounting of the substrate electrode or the like to affect the heteroepitaxial crystallization of the graphene.

The exemplary embodiment of Figure 9 is not intended to operate a plasma within the reactor. This is because the crystal film growth mechanism is a heteroepitaxial crystal which is adsorbed by the surface (generally only on the catalyst). The growth from the plasma phase has been found to result in most amorphous films, and has also been found to allow for the formation of large particles or dust formation, which can significantly reduce film quality and lead to pinholes that are detrimental to the one to ten atomic layer film. . Conversely, certain exemplary embodiments may include fabricating graphite (eg, single crystal graphite), etching it to a graphane (eg, a certain n-value graphane), and converting the graphane to graphene (eg, converting to HEG graphite) Alkene). Of course, an in-situ endpoint technique can be implemented as a feedback parameter.

In certain exemplary embodiments, an ion beam source can be configured in a straight line, but outside of the reactor of Figure 9, for example, to perform doping in accordance with the above exemplary techniques. However, in certain exemplary embodiments, an ion beam source can be disposed in the body of a reactor.

Demonstration program flow chart

Figure 10 is a graph showing a certain catalyst CVD growth, flaking, and some An example program flow diagram of the transfer technique of the example embodiment. The exemplified glazing shown in Fig. 10 is started, for example, by a conventional glass inspection method (step S1002) and by washing (step S1004). The back stay glass can then be cleaned using ion beam cleaning, plasma ashing, etc. (step S1006). A catalyst (for example, a metal catalyst) is disposed on the rear support, for example, using PVD (step S1008). It should be noted that in certain exemplary embodiments of the invention, the cleaning procedure of step S1006 can be accomplished in a graphene applicator/reactor. In other words, in certain exemplary embodiments, for example, depending on whether a metal catalyst layer is deposited in or before the applicator/reactor, the back strut glass with or without the metal catalyst film formed thereon may be S1006 was previously loaded into the graphene applicator/reactor. An n-layer graphene catalyst deposition may occur (step S1010). In certain exemplary embodiments, graphene may be etched by introduction of a hydrogen atom (H*), and graphene may be selectively doped, for example, depending on the target application (step S1012). The end of graphene formation is detected, for example, by determining whether sufficient graphene has been deposited, and/or releasing H* etching is sufficient (step S1014). In order to prevent graphene formation, a rapid quenching procedure is used, and the post-support glass on which graphene is formed leaves the reactor/applicator (step S1016). Visual inspection can optionally be performed at this point.

After graphene formation, a graphene transferable polymer can be disposed on the graphene by spin, doctor blade or other coating technique (step S1018). This product is optionally inspected, for example, to determine if a desired color change has occurred. If so, the polymer can be cured (eg, using heat, UV radiation, etc.) (step S1020) and, in turn, checked again. The metal catalyst may be insufficiently etched or released (step S1022), For example, to prepare the graphene to peel off (step S1024).

Once the spalling is achieved, the polymer and graphene are selectively inspectable and, in turn, washed, for example, to remove any remaining insufficient etchant and/or non-cured polymer (step S1026). Another selective check procedure can be performed at this point. A surfactant can be applied (step S1028), the pins can be placed at least in the polymer (step S1030), and the film is flipped, for example, with the aid of the pins (step S1032). The spalling procedure is now complete and the graphene is now ready to be transferred to the receiving substrate.

The receiving substrate is prepared, for example, in a clean room (step S1034). The surface of the receiving substrate can be functionalized, for example, by exposing it to a UV light to increase its surface energy, to apply a graphene-based coating or the like thereto (step S1036). The graphene/polymer film can in turn be transferred to the main board (step S1038).

Once the transfer is complete, the receiving substrate having graphene and polymer attached thereto can be fed into a module to remove the polymer (step S1040). This can be accomplished by exposing the polymer to UV light, heat, chemicals, and the like. The substrate having graphene and at least partially dissolved polymer may be further washed (step S1042), and any excess water or other material is evaporated or dried (step 1044). This polymer removal procedure can be repeated as needed.

After the polymer is removed, the sheet resistance of the graphene on the substrate can be measured, for example, by applying a standard four-point probe (step 1046). Optical transmission (e.g., Tvis, etc.) can also be measured (step S1048). Assuming that the intermediate and final products meet the quality criteria, they can be packaged (step S1050).

Using these techniques, the sample film is prepared. The sample films showed a high electrical conductivity of 15500 S/cm and a transparency of greater than 80% at a wavelength of 500-3000 nm. In addition, the films show quantitative chemical and thermal stability. Figure 11 is an image showing a heteroepitaxial growth of graphene exfoliation-transferral alloy film.

Demonstration of graphene-containing applications

As mentioned above indirectly, the graphene-based underlayer can be used in a variety of applications and/or electronic devices. In such exemplary applications and/or electronic devices, the ITO and/or other conductive layers may be replaced only by the graphene-based underlayer. A device made of graphene will typically include contacts made with metals, degenerate semiconductors such as ITO, solar cell semiconductors such as a Si and CdTe, and/or the like.

In addition to having a zero band gap and a loss density state (DOS) at point K in the Brylo area, the independent graphene exhibits metal behavior. However, metal absorption, semiconductor or insulating substrates can change their electronic properties. To complement this, additionally or alternatively, in an exemplary application and/or electronic device, the graphene-based underlayer may be doped according to any semiconductor layer adjacent thereto. That is, in certain exemplary embodiments, if a graphene-based underlayer is adjacent to an n-type semiconductor layer, the graphene-based underlayer may be doped with an n-type dopant. Also, in certain exemplary embodiments, if a graphene-based underlayer is adjacent to a p-type semiconductor layer, the graphene-based underlayer may be doped with a p-type dopant. Of course, the offset of the Fermi level in graphene relative to the cone point can be modeled, for example, using density functional theory (DFT). Band gap calculations show that the metal/graphene interface can be divided into two broad categories, namely, chemisorption and physical adsorption. In the latter case, an upshift (downward) means that electrons (holes) are supplied to the graphene by metal. Therefore, predicting whether metal or TCO will be used depending on the application It is possible to make a junction of graphene.

A first exemplary electronic device in which one or more graphene-based underlayers can be used is a solar photovoltaic device. Such exemplary devices can include a positive electrode or a back electrode. In such devices, the graphene contact can be readily applied to ITO typically used therein. Photovoltaic devices are disclosed, for example, in U.S. Patent Nos. 6,784,361, 6,288,325, 6,613,603 and 6,123,824; U.S. Publication No. 2008/0169021; No. 2009/0032098; 2008/0308147 No. 2009/0020157; and the application serial number Nos. 12/285,374, 12/285,890 and 12/457,006, all of which are hereby incorporated by reference. .

Alternatively or additionally, a doped graphene-based underlayer may be included to match adjacent semiconductor layers. For example, Figure 12 is a schematic cross-sectional view of a solar photovoltaic device comprising a graphene-based underlayer in accordance with certain exemplary embodiments. In the exemplary embodiment of Figure 12, a glass substrate 1202 is provided. For example, and without limitation, the glass substrate 1202 can be any of the glasses described in any of the U.S. Patent Application Serial No. 11/049,292, and/or the entire disclosure of In this article, I think it is a reference. The glass substrate can be selectively structured by nano, for example, to increase the efficiency of the solar cell. An anti-reflective (AR) coating 1204 can be provided on one of the outer surfaces of the glass substrate 1202, for example, to increase transport. The anti-reflective coating 1204 can be a single layer anti-reflective (SLAR) coating (eg, a ruthenium oxide anti-reflective coating) or a multilayer anti-reflective (MLAR) coating. This AR coating can be provided using any suitable technique.

One or more absorber layers 1206 can be provided on the glass substrate 1202 on the opposite side of the AR coating 1204, for example, in the case of a back electrode device such as that shown in the exemplary embodiment of FIG. The absorber layer 1206 can be sandwiched between the first and second semiconductors. In the exemplary embodiment of FIG. 12, the absorber layer 1206 can be sandwiched between the n-type semiconductor layer 1208 (near the glass substrate 1202) and the p-type semiconductor layer 1210 (farther away from the glass substrate 1202). A back contact 1212 (such as aluminum or other suitable material) can also be provided. Rather than providing ITO or other conductive material between the semiconductor 1208 and the glass substrate 1202, and/or between the semiconductor 1210 and the back contact 1212, first and second graphene-based underlayers 1214 and 1216 can be provided. Graphene-based underlayers 1214 and 1216 can be doped to match adjacent semiconductor layers 1208 and 1210, respectively. Thus, in the exemplary embodiment of FIG. 12, graphene-based underlayer 1214 can be doped with an n-type dopant, and graphene-based underlayer 1216 can be doped with a p-type dopant.

Because of the difficulty in directly structuring graphene, a selective layer 1218 can be provided between the glass substrate 1202 and the first graphene-based underlayer 1214. However, because graphene is extremely flexible, it will generally conform to the surface on which it is placed. Thus, the selective layer 1218 may be deformed such that the structure of the layer can be "transferred" or reflected in the substantially conformal graphene-based underlayer 1214. In this regard, the selective layer 1218 can comprise zinc-doped tin oxide (ZTO). It is noted that in certain exemplary embodiments, one or both of the semiconductors 1208 and 1210 can be replaced by a polymeric conductive material.

Because graphene is transparent in the near and mid-infrared range, it means that most of the penetrating long-wavelength radiation can penetrate and produce carriers that penetrate deep into the i-layer of a single and tandem solar cell. This means a structured back The demand for contacts may not be needed for the graphene-based underlayer, as efficiency will increase by a few percentage points.

Screen printing, evaporation and sintering techniques and high temperature CdCl ₂ treatment are currently used for heterojunction of CdS/CdTe solar cells. These batteries have a high fill factor (FF > 0.8). However, the series resistance Rs is a limiting efficiency artifact. In Rs, a distribution portion of the sheet resistance from the CdS layer is contacted with a discrete component associated with CdTe and a graphite substrate on top of it. The use of one or more graphene-based underlayers can help reduce the distribution of Rs while maintaining good heterojunction characteristics. By including graphene in the front and back contact arrangements of a solar structure, a substantial increase in efficiency can be achieved.

It will be appreciated that certain exemplary embodiments may include single-joint solar cells, while certain exemplary embodiments may include front and rear solar cells. Some exemplary embodiments may be CdS, CdTe, CIS/CIGS, amorphous germanium, and/or other types of solar cells.

Another exemplary embodiment that can include one or more graphene-based underlayers is a touch panel display. For example, the touch panel display can be a capacitive or resistive touch panel display that includes ITO or other conductive layers. See, for example, U.S. Patent No. 7,436,393; U.S. Patent No. 7,372,510; U.S. Patent No. 7,215,331; U.S. Patent No. 6,204,897; U.S. Patent No. 6,177,918; and No. 5,650,597, and Serial No. 12/292,406, The disclosure is incorporated herein by reference. ITO and/or other conductive layers can be replaced with a graphene-based underlayer in this touch panel. For example, Figure 13 is a diagram comprising a graphene-based underlayer, in accordance with certain exemplary embodiments. Touch the cross-sectional view of the screen. Figure 13 includes a lower display 1302, which in some exemplary embodiments may be an LCD, plasma or other flat panel display. An optically clear adhesive 1304 couples the display 1302 to a thin glass sheet 1306. A deformable PET foil 1308 is provided as the topmost layer of the exemplary embodiment of FIG. The PET foil 1308 is separated from the thin glass substrate 1306 by substantially a plurality of cylindrical intervals 1310 and side seals 1312. First and second graphene-based underlayers 1314 and 1316 can be provided on the surface of PET foil 1308 proximate display 1302, respectively, and on the surface of thin glass substrate 1306 that faces PET foil 1308. One or both of the graphene-based underlayers 1314 and 1316 can be patterned by ion beam and/or laser etching. It should be noted that the graphene-based underlayer on the PET foil can be transferred from the growth location to the intermediate product using the PET foil itself. In other words, PET foil can be used in place of a photoresist or other material when exfoliating and/or moving it.

A sheet resistance of less than about 500 ohms/square of the graphene-based underlayer is acceptable in a similar embodiment as shown in Figure 13, and a sheet resistance of less than about 300 ohms/square is advantageous for the graphene-based underlayer. .

It will be appreciated that the ITO typically found in display 1302 can be replaced with one or more graphene-based underlayers. For example, when display 1302 is an LCD display, the graphene-based underlayer can be provided as a common electrode on a color filter substrate and/or as a patterned electrode on a so-called TFT substrate. Of course, doped or undoped graphene-based underlayers can also be used in the design and fabrication of individual TFTs. Similar configurations can also be provided for plasma and/or other flat panel displays.

The graphene-based underlayer can also be used to create conductive data/bus bars, bus bars, antennas, and/or the like. Such structures can be formed/applied to glass substrates, tantalum wafers, and the like. 14 is a flow chart showing an exemplary technique for forming a conductive data/bus bar in accordance with certain exemplary embodiments. In step S1401, a graphene-based underlayer is formed on a suitable substrate. In an optional step, step S1403, a protective layer can be provided on the graphene-based underlayer. At step S1405, the graphene-based underlayer is selectively removed or patterned. This removal or patterning can be accomplished by laser etching. In such cases, if the resolution of the laser is good enough, the need for the protective layer can be reduced. Alternatively or additionally, the etching can be performed via exposure to an ion beam/plasma treatment. Also, as described above, H* can be used in connection with a hot wire. When an ion beam/plasma treatment is used for etching, a protective layer may be required. For example, a photoresist material can be used to protect important graphene areas. This photoresist material can be applied, for example, by spin coating or the like in step S1403. In such a case, in another optional step S1407, the selective protection layer is removed. Exposure to UV radiation can be performed, for example, with a suitable photoresist material. In one or more steps not shown, the conductive graphene-based pattern can be transferred to an intermediate or final product on which the pattern has not been formed, for example, using any suitable technique, such as, for example, the techniques described above. .

While certain exemplary embodiments have been described as etching away or removing a graphene-based underlayer, certain exemplary embodiments may readily alter the conductivity of the graphene-based underlayer. In such cases, some or all of the graphene can be removed. However, since the conductivity has been appropriately changed, only the appropriately patterned area Conductive.

15 is a schematic diagram of a technique for forming a conductive data/busbar in accordance with certain exemplary embodiments. As shown in Figure 15, the conductivity of graphene is selectively altered by substantially exposing to an ion beam. A photoresist material is applied to a suitable pattern, for example, to protect the desired portion of the graphene-based underlayer while other portions of the graphene-based underlayer are still exposed to the ion beam/plasma.

Mobility data is shown in the table below after various samples have been deposited and etched.

It will be appreciated that patterning graphene in this and/or other manners is advantageous for a number of reasons. For example, the layer will be very transparent. Therefore, it is possible to provide a "seamless" antenna in which the pattern is not visible. A similar result can be provided for inclusion in a window (eg, for defrosting, antenna use, power supply components, etc.), flat panel (eg, LCD, plasma, and/or other) display devices, skylights, refrigerator/freezer doors / in the window and so on in the bus bar. This can also advantageously reduce the need for black dissolves that are typically found in such products. Additionally, in an electrochromic device, a graphene-based underlayer can be used in place of ITO.

Although certain exemplary applications/devices have been described herein, as described above, it is possible to use a graphene-based conductive layer instead of or in addition to other transparent conductive coatings (TCCS), such as ITO, zinc oxide, and the like.

As used herein, the terms "on", "supported by", and the like should not be construed as meaning that the two elements are directly adjacent to each other unless explicitly stated. In other words, a first layer can be said to be "on" or "supported" by a second layer, even if there are one or more layers between them.

While the present invention has been described with respect to the embodiments of the present invention, it is understood that the present invention is not limited to the disclosed embodiments, and is intended to cover various modifications and equivalents Effect.

Claims (13)

A data/bus bar comprising a graphene-based underlayer supported by a substrate, wherein: a portion of the graphene-based underlayer is exposed to an ion beam/plasma treatment and/or etched with H*, Thereby reducing the electrical conductivity of the portion. For example, the data/bus line of claim 1 is not electrically conductive. The data/bus bar of claim 1 wherein the substrate is a glass substrate. For example, the data/bus bar of claim 1 wherein the substrate is a wafer. The data/bus bar of claim 1 wherein the portion is at least partially removed by exposure to the ion beam/plasma treatment and/or H* etching. An antenna comprising: a graphene-based underlayer supported by a substrate, wherein: a portion of the graphene-based underlayer is exposed to an ion beam/plasma treatment and/or etched with H* The portion of the graphene-based underlayer is thinned compared to other portions of the graphene-based underlayer; wherein the graphene-based underlayer has a visible light transmission of at least 80%. The antenna of claim 6, wherein the graphene-based underlayer has a visible light transmittance of at least 90%. Method for manufacturing an electronic device, the method package Including: providing a substrate; forming a graphene-based underlayer on the substrate; and selectively patterning the graphene-based underlayer by one of: ion beam/plasma exposure and H* etching. The method of claim 8, further comprising: transferring the graphene-based underlayer to a second substrate prior to performing the patterning step. The method of claim 9, wherein the patterning step is performed to reduce the conductivity of the graphene-based underlayer and/or to remove portions of the graphene-based underlayer. The method of claim 9, further comprising: providing a protective mask over the plurality of portions of the graphene based layer prior to performing the patterning step. The method of claim 11, wherein the protective mask comprises a photoresist material. The method of claim 11, further comprising: removing the protective mask.