Organic Thin-film Transistors Research Articles

Surface-Potential-Based Drain Current Model for Ambipolar Organic TFTs

A surface-potential-based drain current model is presented for ambipolar organic thin-film transistors (OTFTs). First, following the multiple trapping and release (MTR) conduction mechanism, a drain current model is presented for unipolar OTFTs considering exponentially distributed trap state density in the energy gap of an organic semiconductor. Next, from the model for unipolar OTFTs, analyzing electrons or (and) holes in different regimes, the model for ambipolar OTFTs is presented. The presented model can describe the drain current by compact expressions and can estimate the trap states density. The model is verified by available experimental data considering temperature characteristics.

Review of recent advances and sensing mechanisms in solid-state organic thin-film transistor (OTFT) sensors

Advances in processing of active layers of organic thin-film transistor (OTFT)-based chemical and biological sensors have enabled significant developments in their performance, achieving part-per-billion molar concentration limits of detection.

Low-temperature crosslinked soluble polyimide as a dielectric for organic thin-film transistors: enhanced electrical stability and performance

We have prepared a low-temperature cross-linked soluble polyimide (SPI) as a dielectric material for organic thin-film transistors (OTFTs) to improve their electrical stability. Two types of SPIs (DOCDA/6FHAB and 6FDA/6FHAB) were synthesized by a one-step polymerization process using 5-(2,5-dioxytetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic anhydride (DOCDA) and hexafluoroisopropylidene diphthalic anhydride (6FDA) as the dianhydrides and 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FHAB) as a diamine. To further enhance the electrical performance, the SPI thin films were crosslinked with methylated/ethylated (hydroxymethyl)benzoguanamine (HMBG) through a low temperature process at 160 °C. Crosslinking considerably improved the insulating properties, resulting in a substantial reduction in leakage current from 10−7 A cm−2 to 10−9 A cm−2 at 2.0 MV cm−1. When crosslinked SPIs were used as gate dielectrics in OTFTs, device stability and reliability, as measured by the off-current, threshold voltage, and hysteresis, improved significantly. Our results demonstrate the potential of crosslinked SPIs as effective gate dielectric materials for advanced organic thin-film transistors.

Microfluidic-organic thin film transistor coupled platform for simple solution exposure

Organic thin film transistors (OTFTs) have been combined with microfluidic in a non distructive process, enabling the simple exposure of the oragnic semicondcutor to different analytes.

Overview of electrohydrodynamic deposition for fabricating organic thin film transistors

This review explores recent advancements in Electrohydrodynamic (EHD) deposition techniques for the fabrication of organic thin-film transistors, highlighting their impact on device performance and potential applications.

High-performance organic thin-film transistors: principles and strategies

Organic thin film transistors (OTFTs) mark a breakthrough in flexible electronics, offering advantages over traditional inorganic semiconductors through their adaptability, cost efficiency, and low-temperature production.

Progress in the Detection of Trap Density of States in Organic Thin Film Transistors

Progress in the Detection of Trap Density of States in Organic Thin Film Transistors

An Organic Thin-Film Transistors (OTFTs) with Steep Subthreshold and Ultra-Low Temperature Solution Processing for Label-Free Biosensing

An Organic Thin-Film Transistors (OTFTs) with Steep Subthreshold and Ultra-Low Temperature Solution Processing for Label-Free Biosensing

Development of degradable networked-organic semiconductors and effects on charge carrier mobility in organic thin-film transistors

Controlling the degradation rates in degradable polymers depends on the type of crosslinker used for transient OTFTs.

Methyl functionalization on polyimide side chains as gate dielectrics for organic transistors

The strategy of methyl functionalization on polyimide side chains may offer new possibilities for achieving high mobility and low threshold voltage in organic thin-film transistors.

(F5PhO)2-F16-SiPc as an air-stable, high-performance n-type semiconductor with poor cannabinoid sensing capabilities

(F5PhO)2-F16-SiPc is an air stable, n-type semiconductor for organic thin-film transistors (OTFTs), however the structural changes that enhance its stability likely cause its lack of response to cannabinoids in a sensor.

Printed organic transistors and complementary ring oscillators operatable at 200 mV

Applications of organic thin-film transistors (OTFTs) include wearable health monitors and next-generation Internet-of-Things systems driven by a small energy-harvesting power supply. Such applications require low voltage and low power consumption organic ICs. In this paper, we demonstrate complementary ICs based on printed p-type and n-type OTFTs operatable at an ultralow supply voltage of 200 mV. For that purpose, threshold voltages were finely tuned by dual-gate structure and self-assembled monolayer. Complementary inverter-based ring oscillators operated at small supply voltages down to 200 mV and exhibited a power consumption as small as 6 pW per stage.

Low-voltage operated organic thin film transistors and integrated devices with photo-cured and patterned siloxane based organic–inorganic hybrid high-k dielectrics

New kinds of UV-patternable organic–inorganic high-k sol–gel materials were synthesized and applied in low-voltage operation organic electronic devices.

Low temperature UV cross-linked fluorinated polyurethane for organic thin film transistors

A FPU dielectric can be cured quickly at low temperature by UV cross-linking, for use in flexible devices; it is suitable for large-area preparation by a solution method and has good solvent resistance. OTFTs with FPU perform better than those with a PU dielectric.

A review on diverse streams of interface engineering for organic thin-film transistors

This review article provides a critical overview of the diverse technological streams of interface engineering formed in the field of OTFTs.

Optimization of thin-film formation of naphthalene tetracarboxylic diimide derivatives with head and tail structure and application to transistors

Herein, we characterized vacuum-evaporated thin-films of several new naphthalene tetracarboxylic diimide derivatives (C12-NTCDI-R) as n-type organic thin-film transistor (TFT) materials. They have head and tail structure with dodecyl chain and phenylalkyl (benzyl or phenylethyl) groups. By introducing fluorine groups into the phenylalkyl groups, the electron transport properties were enhanced. In addition, modifying the substrate surfaces with a fluorine-rich polymer material and annealing at the appropriate temperature allowed the TFT devices with C12-NTCDI-F2Bn (R = 3,5-difluorobenzyl) to reach a maximum electron mobility (μ e) of 0.11 cm2 V−1 s−1. Furthermore, the alteration of the number of methylene carbons in the side chain of phenylalkyl groups in C12-NTCDI-R (namely, phenylethyl was used as R) affected the thermal behavior of their molecules during the thin-film formation. For the TFT device with C12-NTCDI-PhEt (R = phenylethyl), the μ e reached the maximum value of 0.16 cm2 V−1 s−1 by just surface modification, without annealing.

Stretchable Semiconducting Polymers with Hydrogen-Bonding-Capable Conjugation Breakers: Synthesis and Application in Organic Thin-Film Transistors.

Diketopyrrolopyrrole (DPP)-based conjugated copolymers are important organic semiconductors for applications in high-efficiency organic thin-film transistors (OTFTs). However, the direct application of these polymers with rigid backbones in stretchable devices has limitations. In this study, we designed and synthesized three kinds of DPPBT-based copolymers, DPPBT-A1, DPPBT-A3, and DPPBT-A5, which have amide-coupled alkylene conjugation breakers capable of hydrogen bonding. Linkers with different segment lengths were copolymerized with DPP and bithiophene (BT) backbone units. A DPP-based copolymer with alternating BT moieties, DPPBT, was synthesized as a reference fully conjugated copolymer. The synthesized polymers with freely rotational backbone linkers have sufficient flexibility to develop ordered phase domains, even in thin films, in comparison to the reference copolymer. However, the introduction of the conjugation breakers, which disconnect the intramolecular π-π overlapping, tends to decrease the hole mobility (μ) from 0.76 to 0.20 cm2 V-1 s-1 in the corresponding OTFT devices. The TFT fabricated using DPPBT-A3 showed a mobility of 0.50 cm2 V-1 s-1, and the mobility value did not show a significant change even when elongated by more than 50%. Therefore, the molecular design strategy of introducing amide-coupled alkylene conjugation breakers into conjugated polymer chains can contribute significantly to the development of high-mobility stretchable conjugated polymers in future.

Ultrahigh-gain organic transistors based on van der Waals metal-barrier interlayer-semiconductor junction.

Intrinsic gain is a vital figure of merit in transistors, closely related to signal amplification, operation voltage, power consumption, and circuit simplification. However, organic thin-film transistors (OTFTs) targeted at high gain have suffered from challenges such as narrow subthreshold operating voltage, low-quality interface, and uncontrollable barrier. Here, we report a van der Waals metal-barrier interlayer-semiconductor junction-based OTFT, which shows ultrahigh performance including ultrahigh gain of ~104, low saturation voltage, negligible hysteresis, and good stability. The high-quality van der Waals-contacted junctions are mainly attributed to patterning EGaIn liquid metal electrodes by low-energy microfluidic processes. The wide-bandgap semiconductor Ga2O3 as barrier interlayer is achieved by in situ surface oxidation of EGaIn electrodes, allowing for an adjustable barrier height and expected thermionic emission properties. The organic inverters with a high gain of 5130 and a simplified current stabilizer are further demonstrated, paving a way for high-gain and low-power organic electronics.

Simulation of Interaction Processes of C20 Fullerene with Graphene

Graphene, a carbon sheet one atom thick, with carbon atoms arranged in a two-dimensional honeycomb configuration, has a number of intriguing properties. Fullerenes are a promising material for creating electro-active elements in solar cells and active layers in thin-film organic transistors. A computer model of the C20 fullerene molecule was constructed using the energy minimization method with the second-generation Brenner potential (REBO). A computer model of "infinite" defect-free graphene was built, designed to consider the process of adsorption of a C20 fullerene molecule on its surface. To study adsorption process computer models of fullerene and "infinite" graphene were approached to the required distance with a different set of geometric arrangement of fullerene with respect to the graphene surface. It has been established that the adsorption of fullerene C20 on the surface of graphene can be carried out in three different ways, differing in the number of interacting fullerene and graphene atoms. The binding energies and adsorption lengths for C20 fullerene molecules adsorbed on the graphene surface in different ways are calculated. The way of adsorption corresponding to the highest binding energy and the shortest adsorption length was revealed.

Trend Synthesis Thin Film Research as Electronic Device (A Review)

A thin film is a material with optical properties highly dependent on the dielectric constant, refractive index, and gap energy. This research aims to identify and analyze research trends in thin-layer synthesis as electronic devices. This research is qualitative. The data used in this research was obtained from documents indexed by Google Scholar from 2014-2023 using Publish or Perish and Dimension.ai. Research procedures use PRISMA guidelines. The data identified and analyzed included the type of publication, author on thin layer synthesis, source of publication, and the title of research on thin layer synthesis that was widely cited. The data analysis method uses bibliometric analysis assisted by VOSviewer software. The results of the study show that the research trend in thin-layer synthesis has experienced a fluctuating increase from 2014 to 2020. The journal containing the most thin-layer synthesis articles is ECS Meeting Abstracts with 676. The results of the density mapping analysis show that the theme that is rarely researched is organic semiconductors, organic thin film transistors, and green synthesis.