Theoretical designing of copolymers of donor-acceptor polymers based on polysilole

Abstract

The electronic structures and conduction properties of quasi-one-dimensional superlattices (copolymers) (A_mB_n)<i>_x</i> of two silole based donor-acceptor polymers PSICO (A)<i>_x</i> and PSICN (B)<i>_x</i> calculated on the basis of the negative factor counting method in the tight-binding approximation arc reported. The repeat unit of PSICO and PSICN consists of

bicyclopentadisilole unit bridged by an electron-accepting group Y(Y= >C=O in PSICO and Y= >C=C(CN)₂ in PSICN). The copolymers, on the basis of the band positions of PSICO and PSICN, arc found to belong to the class of type-II staggered superlattices. The trends in the electronic properties of the copolymers as a function of (i) the block size m of A, (ii) the

block size n of B, (iii ) the block sizes m and n keeping m/n constant and (iv) the arrangement of units in the copolymer chain (periodic or aperiodic) are discussed.