Light-Emitting Diodes (LEDs)

Solid-state  lighting  (SSL)  is  commonly  referring  to  lighting  with  light-emitting  diodes  (LED), organic  light-emitting diodes  (OLED) and  light-emitting polymers  (LEP). At  the moment  there  is still  no  official  definition  for  solid-state  lighting,  the  expression  “solid-state”  refers  to  the semiconductor crystal where charge carriers (electrons and holes) are flowing and originate photons (i.e., light) after radiative recombinations.