Hybrid transparent conducting electrode
11569397 · 2023-01-31
Assignee
Inventors
- Shyam Kumar Choudhary (Mumbai, IN)
- Sumitesh Das (Mumbai, IN)
- Giridhar Udapi Rao Kulkarni (Bangalore, IN)
- Rajashekhar Ningappa Pujar (Bangalore, IN)
Cpc classification
H10K30/82
ELECTRICITY
H01L31/1884
ELECTRICITY
Y02P70/50
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H01L31/022466
ELECTRICITY
International classification
Abstract
The present invention relates to hybrid transparent conducting electrode comprising reduced graphene oxide film, metal mesh and textured glass, wherein the reduced graphene oxide film is coated on the textured glass embedded with the metal mesh or the reduced graphene oxide film is sandwiched between the textured glass and the metal mesh. The present invention also relates to a process of preparing the hybrid conducting transparent conducting electrode. The said transparent conducting electrode exhibits transparency ranging from about 70% to 85% with sheet resistance ranging from about 5 Ω/sq to 100 Ω/sq.
Claims
1. A Hybrid transparent conducting electrode comprising: i. reduced graphene oxide film formed from vapors of shellac; ii. metal mesh; and iii. textured glass, wherein the reduced graphene oxide film is coated on the textured glass embedded with the metal mesh, wherein the metal content on the glass in the electrode is ranging from about 50 mg to 1000 mg; and wherein the electrode has haze of about 5%.
2. The hybrid transparent conducting electrode as claimed in claim 1, wherein the reduced graphene oxide can sustain 6H hardness level.
3. The hybrid transparent conducting electrode as claimed in claim 1, has transparency ranging from about 70% to 85%.
4. The hybrid transparent conducting electrode as claimed in claim 1, has sheet resistance ranging from about 5 Ω/sq to 100 Ω/sq.
5. The hybrid transparent conducting electrode as claimed in claim 1, wherein the reduced graphene oxide film is a monolayer or comprises plurality of layers.
6. The hybrid transparent conducting electrode as claimed in claim 1, wherein the metal mesh comprises metal or alloy, wherein the metal is selected from a group comprising copper, silver, aluminium, gold, tin and nickel and the alloy is selected from a group comprising aluminium-zinc alloy, aluminium-silica alloy, copper-nickel alloy, bronze, nickel-chromium alloy, steel and mild steel.
7. The hybrid transparent conducting electrode as claimed in claim 1, has corrosion rate of about 0.0911 mm/year.
Description
BRIEF DESCRIPTION OF THE ACCOMPANYING FIGURES
(1) In order that the present invention may be readily understood and put into practical effect, reference will now be made to exemplary embodiments as illustrated with reference to the accompanying figures. The figures together with detailed description below, are incorporated in and form part of the specification, and serve to further illustrate the embodiments and explain various principles and advantages, in accordance with the present invention where:
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DETAILED DESCRIPTION OF THE INVENTION
(21) The foregoing description of the embodiments of the invention has been presented for the purpose of illustration. It should not be construed that the scope of the invention is limited to the disclosure herein.
(22) The various embodiments of the hybrid transparent conducting electrode of the present invention along with its process of preparation/fabrication are described below with reference to the figures.
(23) It may further be noted that as used herein and in the appended claims, the singular forms “a”, “an”, and “the” include plural reference unless the context clearly dictates otherwise. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by person skilled in the art.
(24) The present invention relates to hybrid transparent conducting electrode.
(25) In an embodiment, the present invention relates to hybrid transparent conducting electrode comprising reduced graphene oxide film, metal mesh and textured glass.
(26) In an embodiment, the hybrid transparent conducting electrode comprises reduced graphene oxide film, metal mesh and textured glass, wherein the reduced graphene film is coated on the textured glass embedded with the metal mesh.
(27) In another embodiment, the hybrid transparent conducting electrode comprises reduced graphene oxide film, metal mesh and textured glass, wherein the reduced graphene oxide film is sandwiched between the textured glass and metal mesh.
(28) In an embodiment, carbon source of the reduced graphene oxide film is shellac.
(29) In an embodiment, the reduced graphene oxide film in the hybrid transparent conducting electrode is a monolayer.
(30) In another embodiment, the reduced graphene oxide film in the hybrid transparent conducting electrode comprises plurality of layers.
(31) In an embodiment, the metal mesh comprises metal selected from a group comprising copper, silver, aluminum, gold, tin and nickel.
(32) In another embodiment, the metal mesh comprises alloy selected from a group comprising aluminium-zinc alloy, aluminium-silica alloy, copper-nickel alloy, bronze, nickel-chromium alloy, steel and mild steel.
(33) In an embodiment, the hybrid transparent conducting electrode has transparency ranging from about 70% to 85%.
(34) In another embodiment, the hybrid transparent conducting electrode has transparency of about 70%, about 72%, about 74%, about 76%, about 78%, about 80%, about 82%, about 84% or about 85%.
(35) In an embodiment, the hybrid transparent conducting electrode has sheet resistance ranging from about 5 Ω/sq to 100 Ω/sq.
(36) In another embodiment, the hybrid transparent conducting electrode has sheet resistance of about 5 Ω/sq, about 10 Ω/sq, about 15 Ω/sq, about 20 Ω/sq, about 25 Ω/sq, about 30 Ω/sq, about 35 Ω/sq, about 40 Ω/sq, about 45 Ω/sq, about 50 Ω/sq, about 55 Ω/sq, about 60 Ω/sq, about 65 Ω/sq, about 70 Ω/sq, about 75 Ω/sq, about 80 Ω/sq, about 85 Ω/sq, about 90 Ω/sq, about 9511/sq or about 100 Ω/sq.
(37) In an embodiment, the hybrid transparent conducting electrode demonstrates reduced resistance. The reduced resistance of the hybrid transparent conducting electrode is due to the combined effect of metal mesh and the reduced graphene oxide film on the textured glass substrate.
(38) In an embodiment, the hybrid transparent conducting electrode has corrosion rate is ranging from about 0.09 mm/year to 1.0 mm/year.
(39) In another embodiment, the hybrid transparent conducting electrode has corrosion rate of about 0.09 mm/year, about 0.1 mm/year, about 0.2 mm/year, about 0.3 mm/year, about 0.4 mm/year, about 0.5 mm/year, about 0.6 mm/year, about 0.7 mm/year, about 0.8 mm/year, about 0.9 mm/year/or about 1.0 mm/year.
(40) In an embodiment, the conductivity of the hybrid transparent conducting electrode is due to the coating of reduced graphene oxide film on the textured glass embedded with the metal mesh.
(41) In another embodiment, the conductivity of the hybrid transparent conducting electrode is due to the reduced graphene oxide film sandwiched between the textured glass and the metal mesh.
(42) In another embodiment, the conductivity of the hybrid transparent conducting electrode is due to metal mesh and reduced graphene oxide embedded on the textured glass.
(43) In an embodiment, the hybrid transparent conducting electrode is stable and can withstand extreme conditions such as high humidity and high temperatures.
(44) The said hybrid transparent electrode was stable at relative humidity ranging from about 0% to 85% and temperature ranging from about 25° C. to 85° C.
(45) The said hybrid transparent electrode was stable at relative humidity of about 85% and at a temperature of about 85° C. for about 18 hours.
(46) The present invention further relates to process of preparing the hybrid transparent conducting electrode.
(47) In an embodiment, the process of preparing the hybrid transparent conducting electrode comprises— texturing the glass or the glass embedded with metal mesh; and coating the textured glass embedded with the metal mesh with the reduced graphene oxide film or coating the textured glass with the reduced graphene oxide film followed by coating the metal mesh,
to obtain the hybrid transparent conducting electrode.
(48) In an embodiment, the process of preparing the hybrid transparent conducting electrode comprises— texturing the glass embedded with metal mesh; and coating the textured glass embedded with metal mesh with reduced graphene oxide film to obtain the hybrid transparent conducting electrode.
(49) In an embodiment, the glass embedded with metal mesh is obtained by coating colloidal solution over the glass by technique including but not limited to drop casting and spin coating, followed by air drying the glass at temperature ranging from about 25° C. to 40° C. for about 60 seconds, which results in formation of crackle template on the glass.
(50) The crackle template on the glass is deposited with the metal selected from a group comprising copper, silver, aluminium, gold, tin and nickel or the alloy selected from a group comprising aluminium-zinc alloy, aluminium-silica alloy, copper-nickel alloy, bronze, nickel-chromium alloy, steel and mild steel, by vacuum deposition methods to obtain metal wire mesh on glass or glass embedded with metal mesh.
(51) In an embodiment, the vacuum deposition method is physical vapor deposition, chemical vapor deposition, low pressure chemical vapor deposition, plasma enhanced chemical vapor deposition, or any combinations thereof.
(52) In an embodiment, glass having the crackle template is subjected to physical vapor deposition, wherein about 50 mg to 1000 mg of the metal or the alloy is embedded on the glass. The physical vapor deposition chamber is closed to attain pressure of about 10.sup.−5 mbar to 10.sup.−6 in about 80 minutes to 90 minutes and the chamber temperature is maintained at about 25° C. to 30° C. The metal is evaporated once the chamber crosses 10.sup.−5 mbar pressure. Once, the metal or the alloy is deposited on the glass, lift-off is performed by dipping the glass in chloroform solution for a period of about 1 minute to 2 minutes to remove the colloidal material.
(53) In another embodiment, about 50 mg, about 100 mg, about 150 mg, about 200 mg, about 250 mg, about 300 mg, about 350 mg, about 400 mg, about 450 mg, about 500 mg, about 550 mg, about 600 mg, about 650 mg, about 700 mg, about 750 mg, about 800 mg, about 850 mg, about 900 mg or about 1000 mg of the metal or the alloy is embedded on the glass.
(54) In an embodiment, texturing the glass embedded with the metal mesh and coating the reduced graphene oxide film on the textured glass embedded with the metal mesh is carried out simultaneously.
(55) In an embodiment, texturing the glass embedded with the metal mesh and coating the reduced graphene oxide comprises heating the glass embedded with metal mesh placed on a textured stainless steel and at least one feeder comprising shellac. The heating is carried out at a temperature ranging from about 400° C. to 1200° C. under vacuum at a pressure ranging from about 10.sup.−1 to 10.sup.−3 mbar for a period of about 1 minute to 15 minutes. The said heating causes the shellac to vaporize and contact the textured glass embedded with the metal mesh, thereby forming coat of the reduced graphene oxide film on the textured glass embedded with metal mesh upon cooling to a temperature ranging from about 25° C. to 50° C.
(56) In another embodiment, the heating is carried out at a temperature of about 400° C., about 500° C., about 600° C., about 700° C., about 800° C., about 900° C., about 1000° C., about 1100° C. or about 1200° C. under vacuum at a pressure of about 10.sup.−1 mbar, about 10.sup.−3 mbar or about 10.sup.−3 mbar, for a period of about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 11 minutes, about 12 minutes, about 13 minutes, about 14 minutes or about 15 minutes.
(57) In an embodiment, reduced graphene oxide coat is formed on the texture glass upon cooling to a temperature of about 25° C., about 30° C., about 35° C., about 40° C., about 45° C. or about 50° C.
(58) In an embodiment, the feeder comprises shellac at a concentration ranging from about 10 gram/liter to 200 gram/liter. The shellac is casted on the feeder by technique including but not limited to spin coating, dipping, spraying, bar coating, slot coating and drop casting.
(59) In another embodiment, the feeder comprises shellac at a concentration of about 10 gram/liter, about 20 gram/liter, about 40 gram/liter, about 60 gram/liter, about 80 gram/liter, about 100 gram/liter, about 120 gram/liter, about 140 gram/liter, about 150 gram/liter, about 160 gram/liter, about 180 gram/liter or about 200 gram/liter.
(60) In an embodiment, the process of preparing the hybrid transparent conducting electrode comprises— texturing the glass and coating the textured glass with reduced graphene oxide film; and coating the metal mesh on the reduced graphene oxide film of the textured glass to obtain the hybrid transparent conducting electrode.
(61) In another embodiment, the process of preparing the hybrid transparent conducting electrode comprises— texturing the glass and coating the glass with reduced graphene oxide film; coating colloidal solution on top of textured reduced graphene oxide film; drying the glass to obtain crackle template; and coating metal on the crackle template, followed by washing the template to obtain the hybrid transparent conducting electrode.
(62) In an embodiment, texturing the glass and coating the reduced graphene oxide comprises heating the glass placed on a textured stainless steel and at least one feeder comprising shellac. The heating is carried out at a temperature ranging from about 400° C. to 1200° C. under vacuum at a pressure ranging from about 10.sup.−1 mbar to 10.sup.−3 mbar for a period ranging from about 1 minute to 15 minutes. The said heating causes the shellac to vaporize and contact the textured glass, thereby forming coat of the reduced graphene oxide on the textured glass upon cooling to a temperature ranging from about 25° C. to 50° C.
(63) In another embodiment, the heating is carried out at a temperature of about 400° C., about 500° C., about 600° C., about 700° C., about 800° C., about 900° C., about 1000° C., about 1100° C. or about 1200° C. under vacuum at a pressure of about 10.sup.−1 mbar, about 10.sup.−3 mbar or about 10.sup.−3 mbar, for a period of about 1 minute, about 2 minutes, about 3 minutes, about 4 minutes, about 5 minutes, about 6 minutes, about 7 minutes, about 8 minutes, about 9 minutes, about 10 minutes, about 11 minutes, about 12 minutes, about 13 minutes, about 14 minutes or about 15 minutes.
(64) In an embodiment, reduced graphene oxide coat is formed on the texture glass upon cooling to a temperature of about 25° C., about 30° C., about 35° C., about 40° C., about 45° C. or about 50° C.
(65) In an embodiment, the feeder comprises shellac at a concentration ranging from about 10 gram/liter to 200 gram/liter. The shellac is casted on the feeder by technique including but not limited to spin coating, dipping, spraying, bar coating, slot coating and drop casting.
(66) In another embodiment, the feeder comprises shellac at a concentration of about 10 gram/liter, about 20 gram/liter, about 40 gram/liter, about 60 gram/liter, about 80 gram/liter, about 100 gram/liter, about 120 gram/liter, about 140 gram/liter, about 150 gram/liter, about 160 gram/liter, about 180 gram/liter or about 200 gram/liter.
(67) In an embodiment, coating the metal mesh on the reduced graphene oxide film coated textured glass comprises depositing the metal selected from a group comprising copper, silver, aluminium, gold, tin and nickel or the alloy selected from a group comprising aluminium-zinc alloy, aluminium-silica alloy, copper-nickel alloy, bronze, nickel-chromium alloy, steel and mild steel, by vacuum deposition methods.
(68) In an embodiment, in the above described processes of coating reduced graphene oxide film on the textured glass embedded with metal mesh or on the textured glass, the reduced graphene oxide coating is controlled in a specific region by introducing a physical mask which contains hollow region which allows the coating of the reduced graphene oxide in that region.
(69) In an embodiment, the above described processes of preparing hybrid transparent conducting electrode is simple and cost effective.
(70) In the process of the present invention ecofriendly precursor is employed to grow reduced graphene oxide at lower temperatures ranging 750° C. to 850° C. with vacuum ranging of 10.sup.−3 mbar to 10.sup.−2 mbar and at lower time period ranging from about 1 minutes to 15 minutes. Importantly no metal catalyst is employed in the process of preparing the hybrid transparent conducting electrode.
(71) Conventionally, most glasses soften under the graphene synthesis condition (at 650° C.), In order to control the glass flow and deformation of glass in the process of the present invention, metal plate is introduced with desired texture below the glass which uses the glass softening property and control the glass flow which gives raise to textured glass, such that glass deformation is controlled and contained to the texturing available on the metal plate. This way the glass is elegant but can be made to host graphene.
(72) In an embodiment, the
(73) In an embodiment, the
(74) In an embodiment, the
(75) Also, the reduced graphene oxide coating in the hybrid transparent conducting electrode makes the metal mesh (Cu mesh) corrosion tolerant and it is about 13 times better than the metal mesh (Cu-mesh) alone.
(76) In an embodiment, the
(77) The
(78) In an embodiment, the
(79) In an embodiment, the
(80) Additional embodiments and features of the present invention will be apparent to one of ordinary skill in art based upon the description provided. The embodiments provide various features and advantageous details thereof in the description. Description of well-known/conventional methods and techniques are omitted so as to not unnecessarily obscure the embodiments. The examples provided herein are intended merely to facilitate an understanding of ways in which the embodiments provided may be practiced and to further enable those of skill in the art to practice the embodiments provided. Accordingly, the following examples should not be construed as limiting the scope of the embodiments.
EXAMPLES
Example 1: Preparation of the Hybrid Transparent Conducting Electrode
(81) A. Preparation of Glass Embedded with Metal Wire Mesh/Metal Mesh.
(82) Colloidal solution is made by adding about 0.4 g of resinous particle in solvent (water or diluter) of volume of about 1 ml at a temperature ranging from about 25° C. to 40° C. and sonicating the solution for about 10 minutes. About 0.25 ml of the colloidal solution is coated over the glass surface of about 2″×2″ by drop casting or spin coating, followed by air drying the glass at temperature of about 25° C. to 40° C. for about 60 seconds which results in crack formation on the glass (crackle template).
(83) The crackle template is placed inside Physical vapor deposition (PVD) chamber and about 400 mg of copper is deposited. The chamber is closed to attain pressure of about 10.sup.−5 to 10.sup.−6 mbar in about 80 minutes to 90 minutes and the chamber temperature is maintained at about 25° C. to 30° C. The metal on the glass is evaporated once the chamber crosses the pressure of about 10.sup.−5 mbar and there is deposition of the metal on the crackle template. After, the metal deposition is complete, the crackle template is taken out and lift-off is performed by dipping the crackle template in chloroform solution for about 1 minute to 2 minutes to remove the colloidal material. After lift-off the glass is left with metal wire mesh on the surface.
(84) The above described preparation can be employed for depositing other metal selected from a group comprising silver, aluminium, gold, tin, nickel or the alloy selected from a group comprising aluminium-zinc alloy, aluminium-silica alloy, copper-nickel alloy, bronze, nickel-chromium alloy, steel and mild steel, to obtain glass having the metal mesh on the surface of the glass or glass embedded with metal mesh.
(85) B. Preparation of Carbon Source for Coating Reduced Graphene Oxide Film
(86) A solution of the about 100 mg/L shellac precursor is made by adding about 10 g of shellac in isopropanol solvent of volume of about 100 ml at a temperature ranging from about 25° C. to 90° C. by gentle mixing using magnetic stirrer for about 15 minutes. Said solution is kept as it is in stationary state for about 2 hours to 3 hours for settling down the contamination. About 1.5 ml of the shellac solution is coated over the quartz (feeder) surface of about 2″×2″ by drop casting.
(87) C. Preparation of the Hybrid Transparent Conducting Electrode
(88) The stainless-steel plate with desired texture (illustrated in
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Example 2
(90) A. Corrosion resistance property of hybrid transparent conducting electrode was tested by electrochemical investigations using CH instruments in three electrode configurations. In the 3-electrode configuration, copper mesh (Cu-mesh) or the hybrid transparent conducting electrode (rGO/Cu-mesh/glass) are employed as working electrodes, Platinum counter electrode and standard Ag/Ag/Cl as reference electrode. The area of the working electrode is about 0.98 cm.sup.2 and about 1.28 cm.sup.2 for Cu-mesh and rGO/Cu-mesh/glass, respectively in about 0.1M NaCl electrolyte at a temperature of about 25° C. to 40° C. The cathodic and anodic polarization measurements are performed at a scan rate of 5 mV/s. The corrosion potential (Ecorr) and corrosion current (Icon) are derived through extrapolation from Tafel polarization curve. The corrosion rate is calculated using the equation given below—
CR=(Icorr×K×EW)/(p×A) Where, K, corrosion rate constant=3272 mm/year; EW, equivalent weight=31.7 g for Cu; p, material density=8.94 g/cm3 for Cu and the sample area A in cm.sup.2 and Icon is current density in A/cm.sup.2. The corrosion resistance of rGO to underlying Cu-mesh is studied using electrochemical measurements (see
(91) TABLE-US-00001 TABLE 1 Resistance change of hybrid transparent conducting electrode with respect to different acid and base treatments. Aqueous Resistance Chemical concentraion Before (~kΩ) After l hour (~kΩ) H.sub.2SO.sub.4 95-98% 50 53 HNO.sub.3 67% 28 30 HCl 37% 44 48 H.sub.2O.sub.2 30% 52 54 NaOH 1M 40 41 KOH 1M 42 43 B. Environment chamber test was conducted to test the stability of the hybrid transparent conducting electrode. The Environmental chamber test was conducted at about 85% relative humidity and at temperature of about 85° C.