Method of forming nano-particle array by convective assembly, and convective assembly apparatus for the same

Abstract

A method of forming a nano-particle array by convective assembly and a convective assembly apparatus for the same are provided. The method of forming nano-particle array comprises: coating a plurality of nano-particles by forming a coating layer; performing a first convective assembly by moving a first substrate facing, in parallel to and spaced apart from a second substrate at a desired distance such that a colloidal solution including the coated nano-particles is between the first and second substrate; and performing a second convective assembly for evaporating a solvent by locally heating a surface of the colloidal solution drawn when the first substrate is moved in parallel relative to the second substrate. The present invention provides the method of forming the nano-particle array where nano-particles having a particle size from a few to several tens of nanometers are uniformly arrayed on a large area substrate at a low cost, and the convective assembly apparatus for the same.

1 . A convective assembly apparatus for a nano-particle array, comprising:
 a tank containing a colloidal solution comprising a plurality of nano-particles;   a first substrate and a second substrate which are partially immersed in the tank and positioned to face each other and be apart from each other at a desired distance to allow movement between the first substrate and the second substrate;   a lift-up unit for raising up the first substrate at a desired raising speed relative to the second substrate; and   to a heating unit for locally heating a front portion of the colloidal solution drawn into the space between the first substrate and the second substrate, when the first substrate is raised relative to the second substrate.   
     
     
         2 . The apparatus of  claim 1 , further comprising a feedback control unit for controlling at least one process variable such as the amount of heat at the front portion of the colloidal solution and a raising speed of the first substrate relative to the second substrate in response to a change in vapor pressure measured at the front portion of the colloidal solution. 
     
     
         3 . A convective assembly apparatus for a nano-particle array, comprising:
 a fixed substrate including an opening for supplying a colloidal solution comprising nano-particles;   a sliding substrate positioned under the fixed cover facing and spaced apart at a desired distance from the fixed substrate in parallel to allow movement between the fixed substrate and the sliding substrate;   at least one driving roller for moving the sliding substrate at a constant speed relative to the fixed substrate; and   a heating unit for locally heating a front portion of the colloidal solution drawn when the sliding substrate is raised relative to the fixed substrate.   
     
     
         4 . The apparatus of  claim 3 , wherein the opening is connected to a tank containing the colloidal solution through a pipe, and the colloidal solution is continuously supplied in a space between the fixed cover and the sliding substrate through the opening of the fixed substrate. 
     
     
         5 . The apparatus of  claim 3 , further comprising a feedback control unit for controlling at least one process variable such as heat applied to the front portion of the colloidal solution and a moving speed of the sliding substrate in response to a change in vapor pressure measured at the front portion of the colloidal solution.