A low contact resistance achieved on top-gated organic field-effect transistors by using coplanar and pseudo-staggered device architectures, as well as the introduction of a dopant layer, is reported. The top-gated structure effectively minimizes the access resistance from the contact to the channel region and the charge-injection barrier is suppressed by doping of iron(III)trichloride at the metal/organic semiconductor interface. Compared with conventional bottom-gated staggered devices, a remarkably low contact resistance of 0.1-0.2 kΩ cm is extracted from the top-gated devices by the modified transfer line method. The top-gated devices using thienoacene compound as a semiconductor exhibit a high average field-effect mobility of 5.5-5.7 cm 2 V -1 s -1 and an acceptable subthreshold swing of 0.23-0.24 V dec -1 without degradation in the on/off ratio of ≈10 9. Based on these experimental achievements, an optimal device structure for a high-performance organic transistor is proposed.
- contact resistance
- organic field-effect transistors (OFETs)
ASJC Scopus subject areas
- Materials Science(all)
- Condensed Matter Physics