photons---majority carriers holes ---cathode pole near to p -type...Ec--conduction band..
Neutrons --majority carriers electrons --Anode near to n-type.. Ev--Valency band...
Energy gap--forbidden gap--diffusion layer..
Semiconductors are of two types..
Pure-semiconductor..intrinsic example GaAs, In-P
Extrinsic-semiconductor ..example Si, Ge.
LED functioning...
LED works in forward bias only..
Laser -light amplification simulated emissions of radiation..
