LED devices having high-quality single crystal ZnO structures for spreading currents and extracting light out of the LEDs are disclosed. In one aspect, a LED device is provided to include a substrate; a first semiconductor layer exhibiting a first conductivity type and formed over the substrate; an active light-emitting structure formed over the first semiconductor layer, the active light-emitting structure operable to emit light under electrical excitation; a second semiconductor layer exhibiting a second conductivity type and formed over the active light-emitting structure; and a single crystal ZnO structure formed over the second semiconductor layer and including a bottom single crystal ZnO portion over the second semiconductor layer and a top single crystal ZnO portion extending from the bottom single crystal ZnO portion, wherein the bottom single crystal ZnO portion is a contiguous single crystal ZnO portion without having voids.