Dependence of field-effect mobility and contact resistance on nanostructure in regioregular poly(3-hexylthiophene) thin film transistors

作者：Singh K A^*; Sauve G; Zhang R; Kowalewski T; McCullough R D; Porter L M

来源：Applied Physics Letters, 2008, 92(26): 263303.

DOI：10.1063/1.2955515

The mobility and contact resistance of transistors based on regioregular poly(3-hexylthiophene) (P3HT) with Ti/Pt electrodes were investigated as a function of the molecular weight (M(W)) of P3HT. For an increase in M(W) from 5.5 to 11 kDa, the mobility increased from 0.04 to 0.16 cm(2) V(-1) s(-1), whereas the contact resistance decreased from 1.7 to 0.6 M Omega. Further increases in M(W) yielded an apparent saturation in both the mobility and the contact resistance. A nanofibrilar morphology was observed where the width of the nanofibrils increases with M(W). A qualitative model based on polymer chain folding is proposed to explain the electrical results.

• 出版日期2008-6-30