Influence of low temperature annealed ultrathin CYTOP buffer layer on the performance of single crystal organic field-effect transistors

We fabricated the organic field-effect transistors (OFETs) integrating C-8-BTBT single crystalline microribbon arrays as the organic semiconductor. A low temperature (60 degrees C) annealed ultrathin CYTOP buffer layer was inserted between the semiconductor and the electrodes to improve the performance of the OFETs. The charge mobility was increased from 1.7 to 3.6 cm(2) V-1 s(-1) through inserting the buffer layer. The performance enhancement was attributed to the significant decrease of the large contact resistance of the OFETs caused by the thick C-8-BTBT single crystalline microribbons, which was reduced from 1.6 to 0.14 M Omega cm by inserting CYTOP buffer layer with thickness of 6 nm. Meanwhile, the CYTOP buffer layer not only protected the C-8-BTBT single crystalline microribbon arrays from the harm of electrode evaporation, but also had no destructive effect on the C-8-BTBT active layer. The outstanding results show an effective method of reducing the contact resistance to improve the performance of OFETs.