An optoelectronic device comprising a substrate comprising a groove having a first and a second face. The first face of the groove is coated with a conductor material and the second face of the groove coated with a semiconductor material. The conductor material and the semiconductor material are in contact with another semiconductor material in the groove. There is an aperture in the another semiconductor material. The first face, second face, the conductor material and the semiconductor material are all in contact with the another semiconductor material in the groove.