A optoelectronic device comprises a semiconductor stack layer; a first transparent conductive oxide (abbreviate as “TCO” hereinafter) layer located on the semiconductor stack layer, wherein the first TCO layer has at least one opening; and a second TCO layer covering the first TCO layer, wherein the second TCO layer is filled into the opening of the first TCO layer and contacted with the semiconductor stack layer, and one of the first TCO layer and the second TCO layer forms an ohmic contact with the semiconductor stack layer.