This study exploits the carrier transport of an organic semiconductor composite incorporated with carbon nanomaterials. Carbon nanotubes (CNTs) were employed as a conductive inorganic nanofiller, and 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS) was applied as an organic semiconducting material to evaluate gate-voltage (V-Gs) of field effect transistors (FETs). The direct current (DC) electrical conductivity was controlled by adding the CNTs into the composite, and the resulting characteristics of terminals, sources and drain-source voltage (VIA) of transistors were evaluated. Our experimental results revealed that the TIPS/CNT composites offered enhanced DC electrical conductivity, e.g., above 0.195 S/m. These findings demonstrated that the carrier trapping of the organic semiconductor significantly increased by embedding CNTs. The TIPS and TIPS/CNT OFETs were analyzed using the Maxwell-Wagner model to understand the carrier mechanisms in the CNTs embedded OFET device. (C) 2017 Elsevier Ltd. All rights reserved.