A method of fabricating a light extraction layer having a corrugated surface, comprising: forming a transparent optical material layer using a transparent optical material, wherein the transparent optical material is a curable material; and forming a plurality of convex portions on a surface of the transparent optical material layer using a molding plate comprising a plurality of concave portions on a surface of the molding plate; the plurality of convex portions respectively substantially complementary to the plurality of concave portions, wherein forming the plurality of convex portions comprises deforming the transparent optical material layer by pressing the molding plate and the transparent optical material layer against each other thereby forming a plurality of first convex portions on the surface of the transparent optical material layer, prior to deforming the transparent optical material layer, the method further comprises: heating the transparent optical material layer to reduce solvent content; characterized in that, subsequent to deforming the transparent optical material layer, the method further comprises: modifying a surface of the plurality of first convex portions by curing the transparent optical material layer; subsequent to modifying the surface of the plurality of first convex portions, re-pressing the molding plate and the transparent optical material layer against each other to re-shape the plurality of first convex portions to conform to the shape defined by the molding plate; and reiterating the modifying and re-pressing steps at least once. forming a transparent optical material layer using a transparent optical material, wherein the transparent optical material is a curable material; and forming a plurality of convex portions on a surface of the transparent optical material layer using a molding plate comprising a plurality of concave portions on a surface of the molding plate; the plurality of convex portions respectively substantially complementary to the plurality of concave portions, wherein forming the plurality of convex portions comprises deforming the transparent optical material layer by pressing the molding plate and the transparent optical material layer against each other thereby forming a plurality of first convex portions on the surface of the transparent optical material layer, prior to deforming the transparent optical material layer, the method further comprises: heating the transparent optical material layer to reduce solvent content; characterized in that, subsequent to deforming the transparent optical material layer, the method further comprises: modifying a surface of the plurality of first convex portions by curing the transparent optical material layer; subsequent to modifying the surface of the plurality of first convex portions, re-pressing the molding plate and the transparent optical material layer against each other to re-shape the plurality of first convex portions to conform to the shape defined by the molding plate; and reiterating the modifying and re-pressing steps at least once. heating the transparent optical material layer to reduce solvent content; characterized in that, subsequent to deforming the transparent optical material layer, the method further comprises: modifying a surface of the plurality of first convex portions by curing the transparent optical material layer; subsequent to modifying the surface of the plurality of first convex portions, re-pressing the molding plate and the transparent optical material layer against each other to re-shape the plurality of first convex portions to conform to the shape defined by the molding plate; and reiterating the modifying and re-pressing steps at least once. modifying a surface of the plurality of first convex portions by curing the transparent optical material layer; subsequent to modifying the surface of the plurality of first convex portions, re-pressing the molding plate and the transparent optical material layer against each other to re-shape the plurality of first convex portions to conform to the shape defined by the molding plate; and reiterating the modifying and re-pressing steps at least once.