P-type Nanocomposite Thin-Film Transistors based on Pentacene and Silver Nanowires: Fabrication and Electrical Characterization

Abstract

The work of this thesis reports the fabrication of a nanocomposite p-type semiconductor material as a new approach for p-type organic thin-film transistors (TFTs) with potential applications in transparent and flexible electronics. The nanocomposite is based on the combination of a thin-film of Pentacene, as the organic p-type semiconductor, with metallic silver nanowires (AgNWs), as conductivity booster nanostructures, embedded inside the Pentacene matrix. This approach has never been reported yet in the literature with this choice of materials, but it is inspired by other similar works published in the literature that used n-type oxide semiconductor based TFTs. A nowadays need of well performing p-type TFTs is what motivated this thesis work, to proof the aforementioned observed concept in a p-type semiconductor, like Pentacene, for the first time.

Fabricated nanocomposite devices exhibited field-effect mobilities in saturation regime (𝜇SAT) of 3.4x10^-3 cm^2V^-1s^-1 and On-Off current ratios in the order of 10^3, which are low values compared to the ones demonstrated in the literature for other materials. Nevertheless, as a proof of concept, this results already show an improvement of the carrier mobility in one order of magnitude in comparison with other fabricated TFT devices of Pentacene, without the presence of the AgNWs, which achieved saturation mobilities of 4.5x10^-4 cm^2V^-1s^-1. Proving, therefore, the interest of the nanocomposite approach with further optimization in the fabrication processes to be done in the future.