| The synthesis of 1,4-bis(2-thienyl)-2,5-dicyclohexyl methyloxybenzene (BTCMB), 3,4-ethylenedioxythiophene (EDOT), 5-octyldioxeno (2,3-c) thiophene (EDOT-C8) and 5-tetradecyldioxeno (2,3-c) thiophene (EDOT-C;Poly(3,4-ethylenedioxythiophene) and its alkyl derivatives show high absorbance (dark blue, opaque) in the visible region in their reduced, insulating state and significantly lower absorbance (light blue, relatively transparent) in their oxidized, conducting state. The band gaps (Eg) of poly (5-octyldioxeno (2,3-c) thiophene) (PEDOT-C8) and poly (5-tetradecyldioxeno (2,3-c) thiophene) (PEDOT-C14) are 1.77 and 1.75 eV respectively. When these polymers are oxidized, at intermediate doping level, bipolarons are observed. In the highly oxidized state, these polymers also show only a single absorbance in the NIR suggesting metallic-like charge carriers. Long term switching studies of PEDOT and its derivatives were conducted in 0.1 M TBAP/CH... |
