Metal nanowire having core-shell structure coated with graphene, and manufacturing method therefor
The present invention relates to a method for manufacturing a nanowire of a core-shell structure including a metal nanowire core and a graphene shell, comprising the steps of: providing a metal nanowire; and coating the metal nanowire with graphene by a plasma chemical vapor deposition method. In addition, the present invention relates to: a nanowire having a core-shell structure including a metal nanowire core and a graphene shell; and a transparent electrode formed from the nanowire. The transparent electrode formed from the nanowire having a core-shell structure has advantages of having controllable copper oxidation characteristics, being optically, electrically and mechanically excellent, and enabling the transparent electrode to be manufactured at a low cost.
1. A method of manufacturing a nanowire having a core-shell structure that includes a metal nanowire core and a graphene shell, the method comprising:
providing a metal nanowire into a plasma-processing chamber;
removing an oxide from a surface of the metal nanowire by flowing H 2 gas in the plasma-processing chamber and generating a plasma using said H 2 gas;
removing the H 2 gas from the plasma-processing chamber by flowing Ar gas in the plasma-processing chamber; and
coating the metal nanowire with graphene by performing plasma-enhanced chemical vapor deposition of graphene while flowing a mixed gas of Ar at a rate of 120 sccm and CH 4 at a rate between 1 and 30 sccm and using a radio-frequency power from 10 W to 100 W in the plasma-processing chamber from which the H 2 gas has been removed, to form said core-shell structure in which the metal nanowire core is surrounded by said graphene shell.
2. The method according to claim 1 , wherein said coating includes coating the metal nanowire with graphene at a temperature of 300° C. to 800° C.
3. The method according to claim 1 , wherein providing the metal nanowire includes providing a copper nanowire.
4. The method according to claim 3 , wherein providing the metal nanowire includes a1) preparing a mixed solution of a copper chloride compound, ethylenediamine, sodium hydroxide, and hydrazine; and b1) mixing the mixed solution with an aqueous polyvinylpyrrolidone solution and causing the same to react in an ice bath.
5. The method according to claim 3 , wherein providing the metal nanowire includes a2) preparing a mixed solution by mixing a copper chloride compound, hexadecylamine, glucose, and water; b2) causing the mixed solution to react in an oil bath for 4 to 8 hours, and removing residual hexadecylamine and glucose from the solution to form a reduced solution; and c2) filtering the reduced solution with a membrane filter and then performing a drying operation.
6. The method of claim 1 , wherein said coating the metal nanowire includes forming the coated nanowire that has a uniform diameter of 20 nm to 150 nm.