Push-Pull π-Electron Phosphonic-Acid-Based Self-Assembled Multilayer Nanodielectrics Fabricated in Ambient for Organic Transistors

摘要

Organic thin-film transistors (OTFTs) are of great current interest for future organic electronics applications such as RF-ID cards, flexible displays, and sensors. Despite recent progress, large OTFT operating voltages, reflecting the intrinsically low mobilities of organic semiconductors, remain one of the major challenges to overcome. For portable applications such as RF-ID tags and displays, it is mandatory to achieve high TFT drain currents (I_(SD)) at acceptably low operating voltages. Several approaches have been proposed to achieve these goals, one of which is to reduce channel lengths due to the inverse proportionality between I_(SD) and the channel length. However, this approach requires expensive lithographies to pattern small features and commensurate scaling of the gate dielectric thickness. For the same device geometry and semiconductor material, equivalent OTFT I_(SD) parameters should be achievable at lower operating voltages by increasing the gate dielectric capacitance C_i, given by eq 1, where ε0 is the vacuum permittivity, k is the dielectric constant, and d is the thickness of dielectric layer.