TRANSPARENT CONDUCTIVE ARTICLE
A transparent conductive article which includes one of more graphene sheets, at least one of the sheets having a sheet resistance of less than 100 Ω/□. The transparent conductive article includes no more than ten graphene sheets. The transparent conductive article can have a transmission of at least 90%. The one or more sheets can have a transmission of at least 90%. A method of making a transparent conductive sheet includes heat treating a chemical vapor deposition (CVD) grown graphene sheet, the sheet having a width dimension of at least 1 cm, in a non-oxidizing environment to a temperature of at least 2400° C. for a sufficient period of time to have a sheet resistance of less than 100 Ω/□ and a transmittance of at least 90%. Prior to heat treating, the sheet is disposed on a suspension media, such as flexible graphite, having a chemical and thermal stability such that the suspension media functionally survives the heat treating step.
1 . A method of making a transparent conductive sheet comprising:
a. heat treating a chemical vapor deposition (CVD) grown graphene sheet, the sheet having a width dimension comprising at least 1 cm, in a non-oxidizing environment to a temperature of at least 2400° C. for a sufficient period of time, whereby a sheet resistance of the heat treated sheet comprises less than 100 Ω/□ and a transmittance of at least 90%.
2 . The method of claim 1 wherein the heat treating comprises heat treating a plurality of the sheets at the same time.
3 . The method of claim 1 further comprising disposing the sheet on a suspension media prior to the heat treating, wherein the suspension media having a chemical and thermal stability such that the suspension media functionally survives the heat treating step.
4 . The method of claim 3 wherein the suspension media comprises flexible graphite.
5 . The method of claim 3 wherein the suspension media supports of the sheet only on a perimeter of the sheet.
6 . The method of claim 3 wherein a coefficient of thermal expansion (CTE) of the suspension media is substantially similar to a CTE of the sheet.
7 . The method of claim 3 further comprising transferring the sheet from a first carrier to the suspension media.
8 . The method claim 1 conducting said heat treating for a period of at least one hour.
9 . The method of claim 1 wherein the temperature comprises at least 2600° C.
10 . A transparent conductive article comprising:
a. at least one sheet and no more than ten sheets of chemical vapor deposition (CVD) grown graphene, each having a sheet resistance of less than 100 Ω/□;
b. the article having a transmission of at least 90%.
11 . The article of claim 10 having a transmission of at least 95%.
12 . The article of claim 10 wherein the article has a sheet resistance comprising less than 100 Ω/□.
13 . The article of claim 12 wherein the article has a sheet resistance comprising less than 50 Ω/□.
14 . The article of claim 13 wherein the article has a sheet resistance comprising less than 25 Ω/□.
15 . The article of claim 10 wherein one or more of the sheets have a sheet resistance of less than 50 Ω/□.
16 . The article of claim 15 wherein one or more of the sheets have a sheet resistance of less than 25 Ω/□.
17 . The article of claim 16 wherein one or more of the sheets have a sheet resistance of less than 10 Ω/□.
18 . The article of claim 10 wherein all the sheets have a sheet resistance of less than 50 Ω/□.
19 . The article of claim 18 wherein all of the sheets have a sheet resistance of less than 10 Ω/□.
20 . An electronic device touchscreen comprising at least one sheet and no more than ten sheets of chemical vapor deposition (CVD) grown graphene, each sheet having a sheet resistance of less than 100 Ω/□, wherein the touchscreen has a transmission of at least 90%.