Effect of a p-6P Induced Layer on the Optoelectronic Performance of Organic Field-Effect Transistors

Abstract

This study investigated the electrical and photosensitive properties of organic field-effect transistors (OFETs) using para-hexaphenyl (p-6P) as induction layers. The widely researched pentacene was employed as the active layer in these devices. Pentacene thin films were epitaxially grown on p-6P template layers, which effectively reduced interfacial disorder and increased the crystalline domain size. Consequently, the pentacene/p-6P transistors exhibited high-quality saturation characteristics along with a negative shift threshold voltage, resulting in a significant enhancement in on-current and a reduction in turn-on voltage. Furthermore, the thickness dependence of template layers on device performance was systematically investigated. At p-6P thickness of 4 nm, Hole mobility increased to 0.1452 cm² V^-1 s^-1, which was about 7 times higher than that of the device without inducted layer (0 nm), The threshold voltage was reduced from -24 V to -6 V. A maximum photoresponsivity (Rmₐₓ) of 1.72 A/W was achieved. Therefore, these results demonstrate that the p-6P template layer provides an effective approach for significantly enhancing the performance of OFETs, offering valuable insights for future device optimization through interfacial engineering.