Solar cells and methods of forming the same

A solar cell comprising:

• a substrate;
• an anti-reflection layer on the substrate;
• a first electrode on the anti-reflection layer;
• a photo-electro conversion layer on the first electrode;
• and
• a second electrode on the photo-electro conversion layer,
• wherein:
• the anti-reflection layer comprises a nanopattern and a nanostructure, and the anti-reflection layer is disposed between the substrate and the first electrode, such that a lower surface of the nanopattern comes in contact with the substrate, the nanostructure is disposed on an upper surface of the nanopattern;
• the nanopattern comprises a transparent conductive oxide;
• the nanostructure comprises a nanoparticle layer;
• the nanoparticle layer includes a plurality of nanoparticles that are covered by and come in contact with the first electrode;
• and
• the nanoparticle layer comprises different material from the nanopattern.