in one aspect , a light emitting unit comprises : a first semiconductor layer having a first electric property ; a second semiconductor layer having a second electric property disposed over the first semiconductor layer ; an active layer disposed between the first semiconductor layer and the second semiconductor layer ; a first electrode disposed on the second semiconductor layer ; a second electrode disposed under the first semiconductor layer ; and a phosphor layer disposed on the first semiconductor layer . the phosphor layer covers the active layer and the second semiconductor layer . the first electrode is exposed out of the phosphor layer .