LAYERED GaAs, METHOD OF PREPARING SAME, AND GaAs NANOSHEET EXFOLIATED FROM SAME

Abstract

The present invention relates to: layered gallium arsenide (GaAs), which is more particularly layered GaAs, which, unlike the conventional bulk GaAs, has a two-dimensional crystal structure, has the ability to be easily exfoliated into nanosheets, and exhibits excellent electrical properties by having a structure that enables easy charge transport in the in-plane direction; a method of preparing the same; and a GaAs nanosheet exfoliated from the same.

What is claimed is: 
     
         1 . A method of preparing layered GaAs, the method comprising:
 step (1) of heat-treating a mixture including K or Na powder, Ga powder, and As powder and cooling the mixture, thereby obtaining a layered compound having a monoclinic crystal structure with the P2 1 /c space group and represented by the chemical formula K 2 Ga 2 As 3  or the chemical formula Na 2 Ga 2 As 3 ; and   step (2) of treating the layered compound with a mixed solution containing a salt capable of selectively removing K ions or Na ions contained in the layered compound and a solvent capable of dissolving the salt, thereby obtaining layered GaAs having a crystalline or an amorphous structure.   
     
     
         2 . The method of  claim 1 , wherein the salt is represented by the following Chemical Formula 1:
   MX a (2≤a≤3)  <Chemical Formula 1>
   wherein, in Chemical Formula 1, M is any one selected among Al, Mg, Zn, Ga, and Mn, and X is any one selected among Cl, Br, and I.   
     
     
         3 . The method of  claim 1 , wherein the solvent includes at least one selected among water, ethanol, a cyclic carbonate-based solvent, a chain carbonate-based solvent, an ester-based solvent, an ether-based solvent, a nitrile-based solvent, and an amide-based solvent. 
     
     
         4 . The method of  claim 1 , wherein the heat treatment of the step (1) is carried out at 650 to 800° C. for 6 to 24 hours. 
     
     
         5 . The method of  claim 1 , wherein the cooling of the step (1) is carried out at a cooling rate of 0.5 to 3° C./hour. 
     
     
         6 . Layered GaAs having a crystalline or an amorphous structure. 
     
     
         7 . The layered GaAs of  claim 6 , which does not produce a peak at 2θ of 26.9±0.2, 44.6±0.2, 52.8±0.2, 64.9±0.2, and 71.5±0.2 in an X-ray diffraction pattern obtained by a powder X-ray diffraction method using Cu-Kα radiation. 
     
     
         8 . A GaAs nanosheet exfoliated from the layered GaAs of  claim 6  and having a crystalline or an amorphous structure. 
     
     
         9 . The GaAs nanosheet of  claim 8 , which has a thickness of 400 nm or less.