Biphenyl heterocyclic-fused polymer and preparing method and application of biphenyl heterocyclic-fused polymer

The invention discloses biphenyl heterocyclic-fused polymer and a preparing method and application of the biphenyl heterocyclic-fused polymer. The structure of the biphenyl heterocyclic-fused polymer is shown as the formula I, wherein R is branched-chain-contained alkyl chains like 2-decyl myristyl, and X and Y are one or two of sulphur atoms, selenium atoms, nitrogen atoms or C-H. The invention further provides a method for preparing a compound in the formula I. A synthetic route of the biphenyl heterocyclic-fused polymer is simple, and the cost is low; the synthetic method has universality, can be popularized to synthesize various kinds of substitute group biphenyl heterocyclic-fused polymer, and is also suitable for preparing higher-molecular-weight polymer semiconductor materials which have indissolvable monomers and are difficult to obtain with other methods. The migration rate and the switch ratio of OFETs prepared with the biphenyl heterocyclic-fused polymer as organic semiconductor layers are relatively high, the maximum migration rate of the compound in the formula I excesses 10 cm V s , and the switch ratio is larger than 10 ; the biphenyl heterocyclic-fused polymer has a certain application prospect in the OFETs.