Tailoring the Dielectric Layer Structure for Enhanced Performance of Organic Field-Effect Transistors: The Use of a Sandwiched Polar Dielectric Layer

Abstract

To investigate the origins of hydroxyl groups in a polymeric dielectric and its applications in organic field-effect transistors (OFETs), a polar polymer layer was inserted between two polymethyl methacrylate (PMMA) dielectric layers, and its effect on the performance as an organic field-effect transistor (OFET) was studied. The OFETs with a sandwiched dielectric layer of poly(vinyl alcohol) (PVA) or poly(4-vinylphenol) (PVP) containing hydroxyl groups had shown enhanced characteristics compared to those with only PMMA layers. The field-effect mobility had been raised more than 10 times in n-type devices (three times in the p-type one), and the threshold voltage had been lowered almost eight times in p-type devices (two times in the n-type). The on-off ratio of two kinds of devices had been enhanced by almost two orders of magnitude. This was attributed to the orientation of hydroxyl groups from disordered to perpendicular to the substrate under gate-applied voltage bias, and additional charges would be induced by this polarization at the interface between the semiconductor and dielectrics, contributing to the accumulation of charge transfer.

Synergistic Enhancement of Thermal Conductivity and Dielectric Properties in Al2O3/BaTiO3/PP Composites

“…Ever-increasing demands of modern microelectromechanical systems and high-temperature electronic and energy storage devices have stimulated the research and design on multifunctional polymer composites [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Although polymers such as polypropylene (PP) exhibit excellent processability, insulativity, and are low-cost [ 8 , 9 , 10 ], the lack of dielectric properties restricts their application in dielectric materials and electronic component fields [ 3 , 4 , 5 ]. In the meantime, dielectric ceramic/polymer composites have received special attention due to their excellent combination of processability and the high dielectric performance of polymer and ceramic [ 11 , 12 ].…”

Synergistic Effect of Excited State Property and Aggregation Characteristic of Organic Semiconductor on Efficient Hole‐Transportation in Perovskite Device

“…If the induced dipole moments would be efficiently generated within the organic thin film by the vertical electric field from the gate voltage, those would be helpful to accumulate additional charges at the interface between the semiconductor (e.g., pentacene) and dielectric (e.g., organic layer with Al 2 O 3 ), consequently decreasing the threshold voltage ( V T ) of OFETs and increasing their drain current ( I DS ). [ 33,34 ] Figure 3a,c,e confirms that V T of OFET decreases from 32.7 to 30.3 V after inserting DPI layer and this can be further decreased to 30.0 V after introducing a DNI layer having higher dipole moment instead of DPI. Moreover, to elucidate the alignment effect of excited state dipole moment, UV light was further illuminated, and we observed additional 5.3 V V T decrease (from 30.3 to 25.0 V in Figure 3c) from the DPI‐added OFET and 5.5 V V T decrease (from 30.0 to 24.5 V in Figure 3e) from the DNI‐added OFET.…”

Improved device efficiency and lifetime of perovskite light-emitting diodes by size-controlled polyvinylpyrrolidone-capped gold nanoparticles with dipole formation

“…Furthermore, In 3+ diffusion from indium-tin-oxide (ITO) into the active layer is one of the critical reasons for the degradation of optoelectronic devices 33 . The strong dielectric feature by PVP capping of MNPs can facilitate the prevention of ion-diffusion/migration in the OIHP layer due to the generation of an induced electric dipole to construct highly efficient and stable optoelectronics 34 , 35 . Therefore, a combination of HTL and PVP-capped MNPs can prove to be a useful approach to enhance the performance and stability of PeLEDs.…”