Photovoltaic device including flexible or inflexible substrate and method for manufacturing the same

1. A method for manufacturing a photovoltaic device, the method comprising:

forming a first electrode on a substrate;

forming a first unit cell on the first electrode;

forming a portion of an intermediate reflector on the first unit cell in a first manufacturing system, the intermediate reflector including a plurality of first and second sub-layers alternately stacked;

exposing to the air the substrate on which the portion of the intermediate reflector is formed;

forming the rest of the intermediate reflector in a second manufacturing system, the intermediate reflector including the plurality of the first and second sub-layers alternately stacked;

forming a second unit cell on the intermediate reflector; and

forming a second electrode on the second unit cell.

2. The method of claim 1 , wherein two adjacent sub-layers among the plurality of the first and second sub-layers alternately stacked have mutually different refractive indices or mutually different crystal volume fractions.

3. The method of claim 2 , wherein the plurality of the first and second sub-layers are formed by alternately changing a flow rate of gas including a non-silicon element between a first flow rate value and a second flow rate value in accordance with the elapsed deposition time.

4. The method of claim 2 , wherein the plurality of the first and second sub-layers are formed by alternately supplying voltages having mutually different first frequency and second frequency to a process chamber.

5. The method of claim 2 , wherein, when the portion of the intermediate reflector and the rest of the intermediate reflector are formed, an impurity is introduced into a process chamber.

6. The method of claim 2 , wherein, after the substrate is exposed to the air, the portion of the intermediate reflector is etched in the second manufacturing system.

7. The method of claim 6 , wherein the etching is performed in a process chamber in which the rest of the intermediate reflector is formed.

8. The method of claim 6 , wherein the portion of the intermediate reflector is etched by using hydrogen plasma.

9. The method of claim 6 , wherein an impurity is introduced at the time of the etching process.

10. The method of claim 6 , wherein, the etching process, the formation of the rest of the intermediate reflector and the formation of a first conductive silicon layer of the second unit cell are performed in a process chamber while a process pressure of the process chamber is maintained constant.

11. The method of claim 2 , wherein the intermediate reflector is formed such that a concentration of a non-silicon element contained in the plurality of the first and second sub-layers respectively increases more the farther it is from a light incident side.

12. The method of claim 2 , wherein, when the intermediate reflector is composed of an n-type nanocrystalline silicon based material, a unit cell closer to a light incident side between the first unit cell and the second unit cell includes a p-type silicon layer and an intrinsic silicon layer, and wherein the intermediate reflector is formed contacting with the Intrinsic silicon layer.

13. The method of claim 2 , wherein the intermediate reflector is formed in a plurality of process chambers.