Optoelectronic device with transparent insulated current blocking region and uniform current spreading

An optoelectronic device includes a semiconductor stack including a top surface; a current blocking region, including a first pad portion formed on the semiconductor stack and wherein the current blocking region includes transparent insulated material; a first opening, formed in the first pad portion, exposing the top surface of the semiconductor stack; a transparent conductive layer, covering the top surface of the semiconductor stack, including a second opening overlapping the first opening; and a first electrode, formed on the semiconductor stack, including a first pad electrode formed on the first pad portion of the current blocking region; wherein the first pad electrode contacts the semiconductor stack through the first opening and the second opening; wherein the first opening includes a first area, the first pad portion and the first opening compose a total area, and a ratio of the first area to the total area is between 10% and 40%.