POS5-1189
Cross-linked Polyimide Gate Dielectric through Thermal Click Chemistry for Low Temperature Processable Organic Thin Film Transistor
When and Where
Nov 30, -0001
00:00 - 00:00
Presenter(s)
Chae Yeong Lim (Kyungsung Univ.)
Co-Author(s)
Abstract
Organic thin-film transistors (OTFTs) have attracted considerable attention in recent years. The OTFTs can be directly deposited on plastic substrates at low temperature by solution processes. This enables low-cost electronic circuits on flexible substrates. OTFTs could have broad applications in technology such as wearable electronics and radio-frequency identification tags. Dielectric materials play a key role in OTFT device performance. Polyimide polymers have been considered as promising materials for gate-dielectric applications because of their tunable structures, good film-forming properties, interfacial compatibility with organic semiconductors, and solution processability. However, in the fabrication of OTFT devices, the deposition of two or more organic layers sequentially by solution processes could cause dissolution or swelling of the underlayer. Cross linking not only can enhance solvent resistance, but also can improve the electrical robustness of dielectric materials. Cross-linking in the dielectric layer can be achieved by photo or thermal reaction. So far, most of the thermal cross-linking processes for polymer dielectrics were carried out at high curing temperatures (>150 oC), which are not compatible with plastic substrates for flexible electronic applications. Here, we report a new cross-linker, 1,3,5-tris(2-propynyloxy)benzene (TYB), which can be cross-linkable at very low temperature 100 oC. Firstly, azide functionalized soluble polyimide is synthesized, and then cross-linking occurs through azide-alkyne cycloaddition reaction with 1,3,5-tris(2-propynyloxy)benzene (TYB) cross-linker. The metal-insulator-metal (MIM) devices show that they exhibit good leakage current density (3.09x10-8 A/cm2 at 1MV/cm) and dielectric constant (3.42) even when cross-linked at very low temperature. Also, it shows good field effect mobility (0.404 cm2/Vs) and on/off ratio (1.25x105) through the pentacene TFT.
