Method of fabricating patterned substrate
A method of fabricating a patterned substrate, with which the optical performance of a photovoltaic cell including an organic solar cell and an organic light-emitting diode (OLED) can be improved. The method includes generating electrostatic force on a surface of a substrate by treating the substrate with electrolytes, causing nano-particles to be adsorbed on the surface of the substrate, etching the surface of the substrate using the nano-particles as an etching mask, and removing the nano-particles residing on the surface of the substrate.
1. A method of fabricating a patterned substrate of a photovoltaic cell or an organic light emitting diode, the method comprising:
generating electrostatic force on a surface of a substrate by treating the substrate with electrolytes;
causing nano-particles to be adsorbed on the surface of the substrate;
etching the surface of the substrate using the nano-particles as an etching mask; and
removing the nano-particles residing on the surface of the substrate.
2. The method of claim 1 , wherein treating the substrate with the electrolytes comprises:
a first step of submerging the substrate into a solution in which a positively-charged first electrolyte is dissolved and then rinsing the substrate;
after the first step, a second step of submerging the substrate into a solution in which a negatively-charged second electrolyte is dissolved and then rinsing the substrate; and
after the second step, a third step of submerging the substrate into a solution in which the positively-charged third electrolyte is dissolved and then rinsing the substrate.
3. The method of claim 2 , wherein each of the first electrolyte, the second electrolyte and the third electrolyte comprises an organic material that dissolves into a water solution.
4. The method of claim 3 , wherein each of the first electrolyte and the third electrolyte comprises polyallylamine hydrochloride (PAH), and the second electrolyte comprises polystyrene sulfonate (PSS).
5. The method of claim 4 , wherein the first electrolyte, the second electrolyte and the third electrolyte are dissolved in a NaCl solution.
6. The method of claim 2 , wherein treating the substrate with the electrolyte further comprises a fourth step of drying the substrate after the third step.
7. The method of claim 1 , wherein causing the nano-particles to be adsorbed comprises:
submerging the substrate into a solution in which the nano-particles are dispersed; and
taking the substrate out of the solution and drying the substrate.
8. The method of claim 1 , wherein the nano-particles comprise one of oxide-based materials which comprise SiO 2 , TiO 2 and Nb 2 O 3 , or a polymeric material.
9. The method of claim 1 , wherein the surface of the substrate is treated with oxygen plasma before generating the electrostatic force.
10. The method of claim 1 , wherein the substrate comprises one selected from the group consisting of a TCO (transparent conductive oxide) substrate, a sapphire substrate, a gallium nitride substrate and a glass substrate.
11. The method of fabricating a photovoltaic cell comprising forming a pattern on a surface of at least one of an electrode substrate and a glass substrate of the photovoltaic cell using the method as recited in claim 1 .
12. The method of fabricating an organic light emitting diode comprising forming a pattern on a surface of at least one of a glass substrate, an internal light extraction substrate and an external light extraction substrate of the organic light emitting diode using the method as recited in claim 1 .