ELECTRONIC TRANSPORT IN SIGMA-CONJUGATED POLYMERS

Time resolved transport studies which have now been carried out on rep resentative alkyl and aryl substituted Si and Ge backbone polymers dem onstrate that these unipolar systems to transmit holes through the spe cimen bulk with negligible loss of carriers to deep traps, making thes e materials attractive candidates for electronic device applications. Transport has been studied by measuring drift mobilities as a function of field, temperature and composition, using the small signal time-of -flight technique. Transport occurs among chain backbone derived state s, yet exhibits behavior essentially identical to systems in which tra nsiting carriers are known to undergo thermally activated tunneling tr ansitions among discrete molecular sites. Thus it is suggested that di sorder causes the chain backbone to be suborganized into domain like u nits of varying conjugation length. The sensitivity of transport to la rge scale thermodynamic processes, to side group substituent and to th e effect of specific dopants is demonstrated.