| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a light-emitting diode superior in light emission efficiency. <P>SOLUTION: A plurality of microlenses 30 which are made up of substances having a refractive indices smaller than that of a P-GaN layer 20 are formed on the P-GaN layer 20 of the upper portion of an active layer 10. The microlens is formed so that the upper surface is convex, or the upper/lower layers are concave. If there is no microlens 30 inside the P-GaN layer 20, when light emitted from the active layer 10 travels through a path(A) having an angle(θ1) larger than a critical angle, the emitted light cannot be emitted outside since the light is subjected to total internal reflection, and the light travels to a path(B). If there is the microlens 30 inside the P-GaN layer 20, the light is refracted at the microlens 30 and advances to a path (C) from which the light is emitted outside at an angle(θ<SB>2</SB>) smaller than the critical angle based on the radius of curvature of the microlens 30. In this way, the totally internally reflected light emitted from the active layer 10 can be reduced, and the light emission efficiency of the light-emitting diode can be increased. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
