Stability Study of Flexible 6,13-Bis(triisopropylsilylethynyl)pentacene Thin-Film Transistors with a Cross-Linked Poly(4-vinylphenol)/Yttrium Oxide Nanocomposite Gate Insulator

Abstract

Abstract:We investigated the electrical and mechanical stability of flexible 6,13-bis (triisopropylsilylehtynyl)pentacene (TIPS-pentacene) thin-film transistors (TFTs) that were fabricated on polyimide (PI) substrates using cross-linked poly(4-vinylphenol) (c-PVP) and c-PVP/yttrium oxide (Y 2 O 3 ) nanocomposite films as gate insulators. Compared with the electrical characteristics of TIPS-pentacene TFTs with c-PVP insulators, the TFTs with c-PVP/Y 2 O 3 nanocomposite insulators exhibited enhancements in the drain current and the threshold voltage due to an increase in the dielectric capacitance. In electrical stability experiments, a gradual decrease in the drain current and a negative shift in the threshold voltage occurred during prolonged bias stress tests, but these characteristic variations were comparable for both types of TFT. On the other hand, the results of mechanical bending tests showed that the characteristic degradation of the TIPS-pentacene TFTs with c-PVP/Y 2 O 3 nanocomposite insulators was more critical than that of the TFTs with c-PVP insulators. In this study, the detrimental effect of the nanocomposite insulator on the mechanical stability of flexible TIPS-pentacene TFTs was found to be caused by physical adhesion of TIPS-pentacene molecules onto the rough surfaces of the c-PVP/Y 2 O 3 nanocomposite insulator. These results indicate that the dielectric and morphological properties of polymeric nanocomposite insulators are significant when considering practical applications of flexible electronics operated at low voltages.

Hybrid Polymer/Metal Oxide Thin Films for High Performance, Flexible Transistors

“…Yttrium oxide (Y2O3) nanoparticles exhibit a wide band gap of 6.0 eV, which is advantageous to the aspects of illumination stability of TFTs [130]. In this context, TFTs were fabricated on polyimide (PI) substrates using cross-linked poly(4-vinylphenol) (c-PVP)/ Y2O3 nanocomposites as gate insulators [131]. The architecture of the flexible devices was Ag/6,13bis(triisopropylsilylehtynyl)pentacene(TIPS-pentacene)/ c-PVP:Y2O3/c-PVP/PI.…”

“…In greater detail, a TiO2 precursor (titanium(IV) butoxide and acetyl acetone) and poly(4-vinylphenol) (PVP) solution (PVP, poly(melamine-co-formaldehyde) methylated/butylated Yttrium oxide (Y 2 O 3 ) nanoparticles exhibit a wide band gap of 6.0 eV, which is advantageous to the aspects of illumination stability of TFTs [130]. In this context, TFTs were fabricated on polyimide (PI) substrates using cross-linked poly(4-vinylphenol) (c-PVP)/ Y 2 O 3 nanocomposites as gate insulators [131] Kim et al have introduced TiO 2 -polymer composites via cross-linking reactions of these two constituents with low surface energy which allows vertical growth of organic molecules (e.g., pentacene) [132]. In greater detail, a TiO 2 precursor (titanium(IV) butoxide and acetyl acetone) and poly(4-vinylphenol) (PVP) solution (PVP, poly(melamine-co-formaldehyde) methylated/butylated and propylene glycol methyl ether acetate (PGMEA) solvent) mixture were spin-coated on ITO substrates and then annealed at 200 • C for 1 h. Interestingly, poly(melamine-co-formaldehyde) methylated/butylated acts as the cross-linker, which reacts with the hydroxyl group of the PVP and the ligands of the TiO 2 , forming a dense structure.…”

Urbach‐Energy‐Dictated Spatial Propagation of Electrons in Thermodynamically Tuned Amorphous Zirconia Thin Films

“…Metal oxides have recently emerged as a novel class of functional materials with the high potential to replace traditional conductors, semiconductors, and insulators due to their excellent electrical properties, optical transparency, and solution processability. [ 4–8 ] In particular, the solution processability through sol‐gel methods is one of the critical features of metal oxides, since different solution‐based approaches to material solidification have attracted significant interest as a promising next‐generation technique. [ 9–14 ] Among metal oxides used as an insulator, zirconia thin films can offer a better option in a wide variety of applications owing to their solution processability, acceptable relative permittivity (ε r ), low leakage current density ( J leak ), and high transparency in the visible region.…”

Theoretical Study on Synchronous Characterization of Surface and Interfacial Mechanical Properties of Thin-Film/Substrate Systems with Residual Stress Based on Pressure Blister Test Technique

“…Thin-film/substrate systems have found increasing application in many advancing technologies, such as mechanics, civil engineering, and biotechnology [ 1 , 2 , 3 , 4 ]. The reliability of thin-film/substrate systems depends mainly on the interfacial adhesive strength of thin-film/substrate, which is usually from the polymeric adhesives or the generation of thin films.…”