Molecular Self‐Assembled Monolayers and Multilayers for Organic and Unconventional Inorganic Thin‐Film Transistor Applications

Abstract

Principal goals in organic thin‐film transistor (OTFT) gate dielectric research include achieving: (i) low gate leakage currents and good chemical/thermal stability, (ii) minimized interface trap state densities to maximize charge transport efficiency, (iii) compatibility with both p‐ and n‐ channel organic semiconductors, (iv) enhanced capacitance to lower OTFT operating voltages, and (v) efficient fabrication via solution‐phase processing methods. In this Review, we focus on a prominent class of alternative gate dielectric materials: self‐assembled monolayers (SAMs) and multilayers (SAMTs) of organic molecules having good insulating properties and large capacitance values, requisite properties for addressing these challenges. We first describe the formation and properties of SAMs on various surfaces (metals and oxides), followed by a discussion of fundamental factors governing charge transport through SAMs. The last section focuses on the roles that SAMs and SAMTs play in OTFTs, such as surface treatments, gate dielectrics, and finally as the semiconductor layer in ultra‐thin OTFTs.

Influence of Molecular Aggregation on Electron Transfer at the Perylene Diimide/Indium-Tin Oxide Interface

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Fundamental Performance Limits of Carbon Nanotube Thin-Film Transistors Achieved Using Hybrid Molecular Dielectrics

“…Toward this end, we report here the integration of >99% pure semiconducting CNTs with a new class of nanoscopic high-capacitance (630 nF/cm 2 ) hybrid inorganic-organic gate dielectrics 23 to achieve TFT performance unconstrained by traditional trade-offs. The resulting devices simultaneously exhibit low operating voltages (4 V), low sub-threshold swings (150 mV/decade), high normalized on-state conductance (8.5 µS/µm), high transconductance (6.5 µS/µm), and high intrinsic field-effect mobilities (147 cm 2 /Vs) with high on/off ratios (5 x 10 5 ) in ambient conditions.…”

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