An electrode structure is disclosed, which includes a buffer layer disposed on a substrate; and an electrode disposed on a surface of the buffer layer away from the substrate, an edge of the electrode including an extension surface extending from a surface of the electrode away from the substrate, and the extension surface is in contact with a surface of the buffer layer and forms an included angle with a surface of the buffer layer contacting the electrode. An anti-reflection layer is disposed at the edge of the electrode, the anti-reflection layer surrounds and covers the edge of the electrode, and the anti-reflection layer extends to be in contact with the buffer layer. An undercut structure is formed between an outer surface of the anti-reflection layer and the surface of the buffer layer.