Abstract: The aspects of the disclosed embodiments relates to an optoelectronic device including a substrate layer having a first surface plane and a second surface plane opposite and parallel to the first surface plane. The device also includes a mesa structure arranged on the first surface plane of the substrate layer. The mesa structure includes at least one layer of material; and a first surface arranged at an angle ? with respect to the first surface plane of the substrate layer, wherein the angle ? is different from 0° and 180°. The device still further includes a first terminating oxide layer of a first type arranged on the first surface of the mesa structure and the first surface of the mesa structure has been cleaned by removing at least 75% of native oxides on the first surface of the mesa structure before arranging the first terminating oxide layer of a first type thereon.