π-σ-Phosphonic Acid Organic Monolayer/Sol-Gel Hafnium Oxide Hybrid Dielectrics for Low-Voltage Organic Transistors

Anthryl-alkyl-PA (pi-sigma-PA) self-assembled monolayers (SAMs)/hafnium oxide (HfO2) hybrid dielectrics have been integrated into organic thin film transistors (OTFTs) to achieve operating voltages under -1.5V. Using pi-sigma-PA SAMs on sol-gel processed HfO2, pentacene-based OTFTs possess low subthreshold slopes (100 mV dec(-1)), high on-off current ratios (10(5)-10(6)), and hole mobilities as high as 0.22 cm(2) V-(1) s(-1).