Influence of processing conditions on the stability of poly(3-hexylthiophene)-based field-effect transistors

Abstract

Bottom-contact organic field-effect transistors (OFETs) based on poly(3-hexylthiophene)-2,5-diyl were fabricated under different process conditions. The devices displayed drastic differences in their ambient-air stability. Whereas it took only about 10min in air for the off current to increase by one order of magnitude in OFETs prepared with chloroform and hexamethyldisilazane, a 120min exposure to air caused only a slight degradation of OFETs prepared using 1,2,4-trichlorobenzene, n-octadecyltrichlorosilane, and a heat treatment. The differences in the film surface morphology were analyzed and possible mechanisms for the enhanced stability are discussed.