60results about How to "Surface roughening" patented technology

A light guide which guides light emitted from an LED includes a light incident end surface for receiving light, a light outputting surface for outputting a guided light, and a lens forming surface that has a plurality of elongated lenses arranged in parallel to each other and formed along the directivity of light incident from the LED, such that a plurality of micro regions are defined over the plurality of elongated lens. In the vicinity of the LED, a distribution of micro regions having an inclination angle between 20° and 50° is at least 10% over all micro regions. A light deflection element disposed adjacent to the light guide light outputting surface includes a light entrance surface having a plurality of lenses formed thereon that are parallel to each other and extend in a direction parallel to the light guide light incident end surface.

A GaN-based LED structure is provided so that the brightness and luminous efficiency of the GaN-based LED are enhanced effectively. The greatest difference between the GaN-based LEDs according to the invention and the prior arts lies in the addition of a masking buffer layer on top of the p-type contact layer and a p-type roughened contact layer on top of the masking buffer layer. The masking buffer layer could be formed using MOCVD to deposit SixNy (x,y≧1), MgwNz (w,z≧1), or AlsIntGa1-s-tN (0≦s,t<1, s+t≦1) heavily doped with Si and / or Mg. The masking buffer layer is actually a mask containing multiple randomly distributed clusters. Then, on top of the masking buffer layer, a p-type roughened contact layer made of p-type AluInGa1-u-vN (0≦u,v<1, u+v≦1) is developed. The p-type roughened contact layer does not grow directly on top of the masking buffer layer. Instead, the p-type roughened contact layer starts from the top surface of the underlying p-type contact layer not covered by the masking buffer layer's clusters. The p-type roughened contact layer then grows upward until it passes (but does not cover) the mask of the masking buffer layer for a specific distance. The total internal reflection that could have been resulted from the GaN-based LEDs' higher index of refraction than that of the atmosphere could be avoided. The GaN-based LEDs according to the present invention therefore have superior external quantum efficiency and luminous efficiency.

A GaN-based LED structure is provided so that the brightness and luminous efficiency of the GaN-based LED are enhanced effectively. The greatest difference between the GaN-based LEDs according to the invention and the prior arts lies in the addition of a masking buffer layer and a roughened contact layer on top of the masking buffer layer. The masking buffer layer contains randomly distributed clusters made of a group-IV nitride SixNy (x,y≧1), a group-II nitride MgwNz (w,z≧1), or a group-III nitride AlsIntGa1−s−tN (0≦s,t<1, s+t≦1) heavily doped with at least a group-II and group-IV element such as Mg and Si. The roughened contact layer, made of AluInvGa1−u−vN (0≦u,v<1, u+v≦1), starts from the top surface of an underlying second contact layer not covered by the masking buffer layer's clusters, and then grows upward until it passes (but does not cover) the clusters of the masking buffer layer for an appropriate distance. The total internal reflection that could have been resulted from the GaN-based LEDs' higher index of refraction than that of the atmosphere could be avoided.