Abstract: To provide semiconductor films for enabling semiconductor light emitting devices particularly having excellent luminous efficiency as compared with conventional devices to be manufactured with high yields, and semiconductor light emitting devices using the films, the present invention provides an optical substrate with a concavo-convex structure (20) formed on a part or the whole of a main surface, where the concavo-convex structure has regular toothless portions. The concavo-convex structure is comprised of convex portions (21), inter-convex portion bottom portions (flat portions) (22), and a concave portion (23) (toothless portion) having a flat plane in a position lower than a main surface formed of the inter-convex bottom portions.

Abstract: An optical substrate PP (10) is provided with a substrate body, and a concavo-convex structure (20) comprised of a plurality of convex portions (20a) provided on the main surface of the substrate body, where at least one pattern (X) observable with an optical microscope is drawn on the main surface, an interval of the pattern (X) is larger than a pitch of the concavo-convex structure (20), and in an optical microscope image of the pattern (X), a first region (Xa) is capable of being distinguished from a second region (Xb) by a difference in light and dark, a plurality of first regions (Xa) is arranged apart from one another at intervals, and the second region (Xb) connects between the first regions (Xa), so as to concurrently actualize increases in internal quantum efficiency IQE and improvements in light extraction efficiency LEE of a semiconductor light emitting device which have been mutually tradeoffs.