Why does the LED structure "favorizes" p-type semiconductor? Hi all, At first I apologize if my English makes this post harder to understand ;). I am trying to figure out why there is always P-type semiconductor flashing outside in LEDs, both planar and edge ones - P-type region is the active region, why not N-type sometimes? Radiative recombination occurs within the area that overlaps both semiconductors - why then p-type is better to be exposed? I am thinking if it has something to do with direct/indirect band gap or maybe quantum efficiency of p/n semiconductors - but if there is any n-type semiconductor with direct band gap then I'm wrong. Regards.