Most of currently available semiconductor are elemental semiconductors Si or Ge and compound inorganic semiconductors. From 1990 onwards devices using organic semiconductors and semiconducting polymers have been developed. These are futuristic technology in gradients. The (a) in organic (b) organic and (c) organic polymer semiconductors are
(1) (a) GaAs (b) CdSe (c) anthracene
(2) (a) GaAs (b) anthracene (c) polyanline
(3) (a) anthracene (b) GaAs (c) polyanline
(4) (a) CdSe (b) polyanline (a) anthracene
