Quaterthiophene derivative and its preparation method and use

The invention discloses a quaterthiophene derivative and its preparation method and use. The quaterthiophene derivative has a structural formula I, wherein R represents hydrogen, alkyl or aryl. The invention also provides the preparation method of the quaterthiophene derivative having the structural formula I. The preparation method has a simple and effective synthesis route, adopts cheap commercial products as raw materials so that a synthesis cost is low, has universality and can be popularized and used in synthesis of other various substituent-substituted quaterthiophene derivatives. An organic field-effect transistor (OFET) is prepared from the quaterthiophene derivative which is [1] benzothieno[3''. 2'': 4', 5']thieno[2'. 3': 4, 5]thieno[2, 3-b][1]benzothiophene as an organic semiconductor layer has high mobility ratios and a switch ratio, wherein the maximum mobility ratio is 0.05cm Vs and the switch ratio is more than 10 and thus the OFET has good application prospects in OFET devices.