Showing papers on "Thin-film transistor published in 2011"
TL;DR: It is shown that mixing fine droplets of an antisolvent and a solution of an active semiconducting component within a confined area on an amorphous substrate can trigger the controlled formation of exceptionally uniform single-crystal or polycrystalline thin films that grow at the liquid–air interfaces.
Abstract: Printing electronic devices using semiconducting 'ink' is seen as a promising route to cheap, large-area and flexible electronics, but the performance of such devices suffers from the relatively poor crystallinity of the printed material. Hiromi Minemawari and colleagues have developed an inkjet-based printing technique involving controlled mixing on a surface of two solutions — the semiconductor (C8-BTBT) in its solvent and a liquid in which the semiconductor is insoluble. The products of this antisolvent crystallization technique are thin semiconductor films with exceptionally high and uniform crystallinity. The use of single crystals has been fundamental to the development of semiconductor microelectronics and solid-state science1. Whether based on inorganic2,3,4,5 or organic6,7,8 materials, the devices that show the highest performance rely on single-crystal interfaces, with their nearly perfect translational symmetry and exceptionally high chemical purity. Attention has recently been focused on developing simple ways of producing electronic devices by means of printing technologies. ‘Printed electronics’ is being explored for the manufacture of large-area and flexible electronic devices by the patterned application of functional inks containing soluble or dispersed semiconducting materials9,10,11. However, because of the strong self-organizing tendency of the deposited materials12,13, the production of semiconducting thin films of high crystallinity (indispensable for realizing high carrier mobility) may be incompatible with conventional printing processes. Here we develop a method that combines the technique of antisolvent crystallization14 with inkjet printing to produce organic semiconducting thin films of high crystallinity. Specifically, we show that mixing fine droplets of an antisolvent and a solution of an active semiconducting component within a confined area on an amorphous substrate can trigger the controlled formation of exceptionally uniform single-crystal or polycrystalline thin films that grow at the liquid–air interfaces. Using this approach, we have printed single crystals of the organic semiconductor 2,7-dioctyl[1]benzothieno[3,2-b][1]benzothiophene (C8-BTBT) (ref. 15), yielding thin-film transistors with average carrier mobilities as high as 16.4 cm2 V−1 s−1. This printing technique constitutes a major step towards the use of high-performance single-crystal semiconductor devices for large-area and flexible electronics applications.
1,505 citations
TL;DR: The formation of amorphous metal oxide semiconducting thin-films using a ‘sol–gel on chip’ hydrolysis approach from soluble metal alkoxide precursors affords unprecedented high field-effect mobilities, reproducible and stable turn-on voltages Von≈0 V and high operational stability at maximum process temperatures as low as 230 °C.
Abstract: A low-temperature, solution-based preparation of amorphous, metal oxide semiconducting thin-films is reported. This ‘sol–gel on chip’ hydrolysis approach yields thin-film transistors with high field-effect mobilities, reproducible and stable turn-on voltages and high operational stability.
895 citations
TL;DR: This work demonstrates an organic channel light-emitting transistor operating at low voltage, with low power dissipation, and high aperture ratio, in the three primary colors, comparable to that of polycrystalline-silicon backplane transistor-driven display pixels.
Abstract: Intrinsic nonuniformity in the polycrystalline-silicon backplane transistors of active matrix organic light-emitting diode displays severely limits display size. Organic semiconductors might provide an alternative, but their mobility remains too low to be useful in the conventional thin-film transistor design. Here we demonstrate an organic channel light-emitting transistor operating at low voltage, with low power dissipation, and high aperture ratio, in the three primary colors. The high level of performance is enabled by a single-wall carbon nanotube network source electrode that permits integration of the drive transistor and the light emitter into an efficient single stacked device. The performance demonstrated is comparable to that of polycrystalline-silicon backplane transistor-driven display pixels.
436 citations
TL;DR: A donor-acceptor polymer semiconductor, PDQT, comprising diketopyrrolopyrrole (DPP) and β-unsubstituted quaterthiophene (QT) for organic thin film transistors (OTFTs) is reported, which forms ordered layer-by-layer lamellar packing with an edge-on orientation in thin films even without thermal annealing.
Abstract: A donor-acceptor polymer semiconductor, PDQT, comprising diketopyrrolopyrrole (DPP) and β-unsubstituted quaterthiophene (QT) for organic thin film transistors (OTFTs) is reported. This polymer forms ordered layer-by-layer lamellar packing with an edge-on orientation in thin films even without thermal annealing. The strong intermolecular interactions arising from the fused aromatic DPP moiety and the DPP-QT donor-acceptor interaction facilitate the spontaneous self-assembly of the polymer chains into close proximity and form a large π-π overlap, which are favorable for intermolecular charge hopping. The well-interconnected crystalline grains form efficient intergranular charge transport pathways. The desirable chemical, electronic, and morphological structures of PDQT bring about high hole mobility of up to 0.97 cm(2)/(V·s) in OTFTs with polymer thin films annealed at a mild temperature of 100 °C and similarly high mobility of 0.89 cm(2)/(V·s) for polymer thin films even without thermal annealing.
387 citations
TL;DR: In this article, the state-of-the-art of metal oxide thin-film transistors (TFTs) is discussed, including the exploration of new channel materials, the realization of low-resistance ohmic contacts and the implementation of high-k dielectric materials as the gate insulator.
Abstract: The purpose of this paper is to give an overview of the state-of-the-art of metal oxide thin-film transistors (TFTs). First, the question of how to achieve high-performance oxide TFTs is addressed, including the exploration of new channel materials, the realization of low-resistance ohmic contacts and the implementation of high-k dielectric materials as the gate insulator. The electrical instability of the oxide TFTs is also discussed, which is critical for their application in flexible backplane electronics: special attention is given to the understanding of the degradation mechanism of oxide TFTs against bias thermal stress (BTS) and light illuminated BTS. Finally, the recent application of oxide TFTs in active matrix displays, such as electronic paper, liquid crystal displays and organic light-emitting diodes, is addressed.
256 citations
TL;DR: In this paper, the electron conduction mechanism in the above-threshold regime in amorphous oxide semiconductor thin film transistors is shown to be controlled by percolation and trap-limited conduction.
Abstract: The electron conduction mechanism in the above-threshold regime in amorphous oxide semiconductor thin film transistors is shown to be controlled by percolation and trap-limited conduction. The band tail state slope controls the field effect mobility, while the average spatial coherence length and potential fluctuation control percolation conduction. In these limits, the field effect mobility is found to follow a power law, from which a universal mobility versus carrier concentration dependence is extracted.
251 citations
TL;DR: The annealing atmosphere of O(2)/O( 3) elevates solution-processed In(2)O(3) TFTs to higher performance at lower processing temperature.
Abstract: Solution-processed In2O3 thin-film transistors (TFTs) were fabricated by a spin-coating process using a metal halide precursor, InCl3, dissolved in acetonitrile. A thin and uniform film can be controlled and formed by adding ethylene glycol. The synthesized In2O3 thin films were annealed at various temperatures ranging from 200 to 600 °C in air or in an O2/O3 atmospheric environment. The TFTs annealed at 500 °C under air exhibited a high field-effect mobility of 55.26 cm2 V−1 s−1 and an Ion/Ioff current ratio of 107. In2O3 TFTs annealed under an O2/O3 atmosphere at temperatures from 200 to 300 °C exhibited excellent n-type transistor behaviors with field-effect mobilities of 0.85−22.14 cm2 V−1 s−1 and Ion/Ioff ratios of 105−106. The annealing atmosphere of O2/O3 elevates solution-processed In2O3 TFTs to higher performance at lower processing temperature.
247 citations
TL;DR: In this paper, the authors reviewed and summarized recent emerging reports that include potential applications, oxide semiconductor materials, and the impact of the fabrication process on electrical performance of thin film transistors with oxide semiconductors.
Abstract: Thin film transistors (TFTs) with oxide semiconductors have drawn great attention in the last few years, especially for large area electronic applications, such as high resolution active matrix liquid crystal displays (AMLCDs) and active matrix organic light-emitting diodes (AMOLEDs), because of their high electron mobility and spatial uniform property. This paper reviews and summarizes recent emerging reports that include potential applications, oxide semiconductor materials, and the impact of the fabrication process on electrical performance. We also address the stability behavior of such devices under bias/illumination stress and critical factors related to reliability, such as the gate insulator, the ambient and the device structure.
243 citations
TL;DR: The results indicate that the TPD is an excellent building block for constructing high-performance polymers for p-type transistor applications due to the excellent processability, substantial hole mobility, and good device stability.
Abstract: We report a new p-type semiconducting polymer family based on the thieno[3,4-c]pyrrole-4,6-dione (TPD) building block, which exhibits good processability as well as good mobility and lifetime stability in thin-film transistors (TFTs). TPD homopolymer P1 was synthesized via Yamamoto coupling, whereas copolymers P2–P8 were synthesized via Stille coupling. All of these polymers were characterized by chemical analysis as well as thermal analysis, optical spectroscopy, and cyclic voltammetry. P2–P7 have lower-lying HOMOs than does P3HT by 0.24–0.57 eV, depending on the donor counits, and exhibit large oscillator strengths in the visible region with similar optical band gaps throughout the series (∼1.80 eV). The electron-rich character of the dialkoxybithiophene counits in P8 greatly compresses the band gap, resulting in the lowest Egopt in the series (1.66 eV), but also raising the HOMO energy to −5.11 eV. Organic thin-film transistor (OTFT) electrical characterization indicates that device performance is very...
235 citations
TL;DR: Radio-frequency identifi cation (RFID) tags, [ 4,5 ] and biosensors, [ 6,7 ] OTFTs usually exhibit very low switching speed and are diffi cult to use instead of inorganic thin-fi lm transistors (TFTs), although they possess the merits of fl exibility and low cost.
Abstract: radio-frequency identifi cation (RFID) tags, [ 4,5 ] and biosensors. [ 6,7 ] OTFTs usually exhibit very low switching speed and are diffi cult to use instead of inorganic thin-fi lm transistors (TFTs), although they possess the merits of fl exibility and low cost. Several challenges for OTFTs of large area are high fi eld-effect mobility ( μ FE ), low operating voltage, and solution processing. The μ FE value and operating voltage of pentacene OTFTs strongly depend on the gate dielectric material. [ 8–10 ]
232 citations
TL;DR: In this article, the fabrication of solution processed aluminum-oxide gate dielectric at the maximum process temperature of 300 °C for a solution based zinc-tin-oxide (ZTO) thin-film transistor was studied.
Abstract: We have studied the fabrication of solution processed aluminum-oxide (AlOx) gate dielectric at the maximum process temperature of 300 °C for a solution based zinc-tin-oxide (ZTO) thin-film-transistor (TFT). An AlOx layer was spin-coated from a solution of aluminum chloride (AlCl3) and then annealed at 300 °C for 1 h. The breakdown electrical field and leakage current density of the AlOx were found to be ∼4 MV cm−1 and 63 μA cm−2 at 1 MV cm−1, respectively. The ZTO layer was prepared by spin-coating or inkjet printing as an active layer of the TFT with AlOx gate dielectric and then annealed at 300 °C for 1 h. The TFT made using spin coating exhibited the field-effect mobility of 33 cm2 V−1s−1 in the saturation region, a gate swing of 96 mV dec.−1 and a threshold voltage of ∼1.2 V and the inkjet printed TFT showed a field-effect mobility of 24 cm2 V−1s−1.
TL;DR: In this paper, the photoreaction properties of amorphous indium-gallium-zincoxide (a-IGZO) thin-film transistors related to the oxygen vacancies VO are discussed.
Abstract: The electrical and photosensitive characteristics of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) related to the oxygen vacancies VO are discussed. With the filling of VO of ratio from 14 to 8, the electron density of the a-IGZO channel decreases from 7.5 to 3.8 ( ×1016 cm-3); the saturation mobility of the TFT decreases from 3.1 to 1.4 cm-2/(V · s); the threshold voltage increases from 7 to 11 V for the TFT with a lower on-current; and the subthreshold slope increases from 2.4 to 4.4 V/dec for the TFT with a higher interface defect density of 4.9 × 1011 cm-2, the worst electrical stability of Vth ~ 10 V, and a hysteresis-voltage decrease from 3.5 to 2 V. The photoreaction properties of a-IGZO TFTs are also sensitive to the oxygen-content-related absorption of the a-IGZO channel. With the lowest content of oxygen in the channel, the TFT has the largest photocurrent gain of 50 μA (Vg = 30 V; Vd = 10 V) and decrease in Vth ( Vth V) at a high light intensity. The light-induced change of TFT characteristics is totally reversible with the time constant for recovery of about 2.5 h.
01 Dec 2011
TL;DR: In this article, the discovery of ferroelectricity in crystalline hafnium silicon oxide was reported, at a composition where the tetragonal phase is not yet stable, are crystallized in presence of a cap.
Abstract: We report the discovery of ferroelectricity in crystalline hafnium silicon oxide If HfO 2 based thin films, at a composition where the tetragonal phase is not yet stable, are crystallized in presence of a cap, the formation of an orthorhombic phase is observed o-HfO 2 shows a piezoelectric response, while a polarization measurements exhibit a remanent polarization above 10 µC/cm2 at a coercive field of 1 MV/cm, confirming this phase to be ferroelectric Transistors fabricated with this material exhibit a permanent and switchable shift of the threshold voltage, allowing the realization of CMOS-compatible ferroelectric field effect transistors (FeFET) with sub 10 nm gate insulators for the first time
TL;DR: In this paper, the authors improved the operation characteristics of amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) to a sub-threshold voltage swing (S) of 217 mV (decade)−1, a mobility of ∼11.4 cm2 (Vs) −1, and a threshold voltage (Vth) of 0.1 V by O3 annealing at a temperature as low as 150 °C.
Abstract: Operation characteristics of amorphous In-Ga-Zn-O (a-IGZO) thin-film transistors (TFTs) were improved to a subthreshold voltage swing (S) of 217 mV (decade)−1, a mobility of ∼11.4 cm2 (Vs)−1, and a threshold voltage (Vth) of 0.1 V by O3 annealing at a temperature as low as 150 °C. However, the O3 annealing at 300 °C caused serious deterioration and exhibited a bistable transition between a large S state and a large Vth state. This transition is attributed to incorporation of excess oxygen and associated subgap defects with a negative-U characteristic. It also explains why a-IGZO channels deposited at high oxygen pressures do not produce operating TFTs.
TL;DR: The advantages of printed electronics and semiconducting single-walled carbon nanotubes (SWCNTs) are combined for the first time for display electronics and the successful control over external OLED is demonstrated.
Abstract: The advantages of printed electronics and semi- conducting single-walled carbon nanotubes (SWCNTs) are combined for the first time for display electronics. Conductive silver ink and 98% semiconductive SWCNT solutions are used to print back-gated thin film transistors with high mobility, high on/off ratio, and high current carrying capacity. In addition, with printed polyethylenimine with LiClO4 as the gating material, fully printed top-gated devices have been made to work as excellent current switches for organic light emitting diodes (OLEDs). An OLED driving circuit composed of two top-gated fully printed transistors has been fabricated, and the successful control over external OLED is demonstrated. Our work demonstrates the significant potential of using printed carbon nanotube electronics for display backplane applications.
TL;DR: In this article, the authors implemented a high-performance amorphous-indium-gallium-zincoxide thin-film transistors (TFTs) on polyimide/polyethylene-terephthalate plastic substrates.
Abstract: Circuits implemented with high-performance amorphous-indium-gallium-zinc-oxide thin-film transistors (TFTs) are realized on polyimide/polyethylene-terephthalate plastic substrates. The TFTs on plastic exhibit a saturation mobility of 19 cm2/V·s and a gate voltage swing of ~0.14 V/dec. For an input of 20 V, an 11-stage ring oscillator operates at 94.8 kHz with a propagation delay time of 0.48 μs. A shift register, consisting of ten TFTs and one capacitor, operates well with good bias stability. AC driving of pull-down TFTs gives the gate driver an improved lifetime of over ten years.
TL;DR: In this paper, a donor-acceptor based solution processable low band gap polymer semiconductor, PDPP-TNT, was synthesized via Suzuki coupling using condensed diketopyrrolopyrrole (DPP) as an acceptor moiety with a fused naphthalene donor building block in the polymer backbone.
Abstract: In this work, we report a novel donor–acceptor based solution processable low band gap polymer semiconductor, PDPP–TNT, synthesized via Suzuki coupling using condensed diketopyrrolopyrrole (DPP) as an acceptor moiety with a fused naphthalene donor building block in the polymer backbone. This polymer exhibits p-channel charge transport characteristics when used as the active semiconductor in organic thin-film transistor (OTFT) devices. The hole mobilities of 0.65 cm2 V−1s−1 and 0.98 cm2 V−1s−1 are achieved respectively in bottom gate and dual gate OTFT devices with on/off ratios in the range of 105 to 107. Additionally, due to its appropriate HOMO (5.29 eV) energy level and optimum optical band gap (1.50 eV), PDPP–TNT is a promising candidate for organic photovoltaic (OPV) applications. When this polymer semiconductor is used as a donor and PC71BM as an acceptor in OPV devices, high power conversion efficiencies (PCE) of 4.7% are obtained. Such high mobility values in OTFTs and high PCE in OPV make PDPP–TNT a very promising polymer semiconductor for a wide range of applications in organic electronics.
Patent•
13 Jan 2011TL;DR: In this article, a planarization pattern is used to fill the via hole in which the first pixel electrode is located and exposes the portion of the firstpixel electrode on the passivation layer.
Abstract: Provided is an organic light-emitting display device (OLED) and method of manufacturing the same. The OLED comprises a substrate and a thin film transistor, with source/drain electrodes, located at a predetermined area on the substrate. A passivation layer is located on the source/drain electrodes with a via hole exposing one of the source/drain electrodes. A first pixel electrode is located at the bottom of the via hole, electrically coupled to the exposed source/drain electrode, and extending onto the side wall of the via hole and the passivation layer. A planarization pattern fills the via hole in which the first pixel electrode is located and exposes the portion of the first pixel electrode on the passivation layer.
TL;DR: In this article, the authors showed that deep defects located above the valence band top are formed at a high density to a depth of ∼2 nm in the surface layer of the a-IGZO channel.
Abstract: Highly stable amorphous-In-Ga-Zn-O (a-IGZO) thin film transistors (TFTs) against constant current stress and negative bias light illumination stress were realized by forming a Y2O3 passivation layer. A recent photoemission study revealed that deep defects located above the valence band top are formed at a high density to a depth of ∼2 nm in the surface layer of the a-IGZO channel. Here, we present that these deep defects are responsible for the instability of a-IGZO TFTs, and the instability can be much improved by passivation with Y2O3, which effectively eliminates the deep subgap defects from the surface of a-IGZO.
Patent•
12 Aug 2011TL;DR: An organic light-emitting display device and a method of its manufacture are provided in this article, whereby manufacturing processes are simplified and display quality may be enhanced, whereby display quality can be enhanced.
Abstract: An organic light-emitting display device and a method of its manufacture are provided, whereby manufacturing processes are simplified and display quality may be enhanced. The display device includes: an active layer of a thin film transistor (TFT), on a substrate and including a semiconducting material; a lower electrode of a capacitor, on the substrate, doped with ion impurities, and including a semiconducting material; a first insulating layer on the substrate to cover the active layer and the lower electrode; a gate electrode of the TFT, on the first insulating layer; a pixel electrode on the first insulating layer; an upper electrode of the capacitor, on the first insulating layer; source and drain electrodes of the TFT, electrically connected to the active layer; an organic layer on the pixel electrode and including an organic emission layer; and a counter electrode facing the pixel electrode, the organic layer between the counter electrode and the pixel electrode.
TL;DR: In this article, the authors demonstrate the importance of the graphene/metal interface on the ohmic contacts of high-frequency graphene transistors grown by chemical vapor deposition (CVD) on copper.
Abstract: This letter demonstrates the importance of the graphene/metal interface on the ohmic contacts of high-frequency graphene transistors grown by chemical vapor deposition (CVD) on copper. Using an Al sacrificial layer during ohmic lithography, the graphene surface roughness underneath the ohmic contacts is reduced by fourfold, resulting in an improvement in the contact resistance from 2.0 to 0.2-0.5 kΩ·μm. Using this technology, top-gated CVD graphene transistors achieved direct-current transconductances of 200 mS/mm, maximum on current densities in excess of 1000 mA/mm, and hole mobilities ~ 1500-3000 cm2/(V·s) on silicon substrates. Radio-frequency device performance yielded an extrinsic current-gain cutoff frequency fT of 12 GHz after pad capacitance de-embedding resulting in an fT - LG product of 24 GHz·μm.
TL;DR: In this paper, a self-aligned coplanar amorphous indium-gallium-zincoxide (a-IGZO) thin-film transistor (TFT) using an a-SiO2 stack layer was presented.
Abstract: We report a self-aligned coplanar amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistor (TFT) using an a-IGZO/SiO2 stack layer. From the channel-length dependence of the total resistance for the TFTs, the channel and parasitic resistances were found to be 8.4 kΩ/μm and 9.7 kΩ/sq, respectively. The fabricated a-IGZO TFT exhibits field-effect mobility of 23.3 cm2/V ·s, threshold voltage of 3.6 V, and gate voltage swing of 203 mV/dec. A 23-stage ring oscillator made of the self-aligned TFTs exhibits a propagation delay time of 17 ns/stage at a supply voltage of 22 V.
TL;DR: In this article, a solution-processed ZnO-TFTs were obtained at 140 °C by microwave irradiation and showed enhanced device characteristics of ∼1.7 cm2 V−1s−1 mobility and a ∼107 on/off current ratio with good air stability.
Abstract: Oxide semiconductors afford a promising alternative to organic semiconductors and amorphous silicon materials in applications requiring transparent thin film transistors (TFTs). We synthesized an aqueous inorganic precursor by a direct dissolution of zinc hydroxide in ammonium hydroxide solution from which a dense and uniform ZnO semiconducting layer is achieved. Solution-processed ZnO-TFTs prepared at 140 °C by microwave irradiation have shown enhanced device characteristics of ∼1.7 cm2 V−1s−1 mobility and a ∼107 on/off current ratio, with good air stability. Spectroscopic analyses confirmed that such a device improvement originates from accelerated dehydroxylation and better crystallization at low temperature by microwave irradiation. Our results suggest that solution-processable oxide semiconductors have potential for low-temperature and high-performance applications in transparent devices.
TL;DR: In this article, the authors discuss the reason for the instability of amorphous indium-gallium-zincoxide (a-IGZO) thin-film transistors (TFTs) under both positive and negative bias stresses.
Abstract: This letter discusses the reason for the instability of amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors (TFTs) under both positive and negative bias stresses. This instability is significantly influenced by the oxygen content in the bulk IGZO and the surrounding environment. The as-fabricated low-temperature devices can only endure a single polarized bias stress. An a-IGZO TFT that is stable toward both positive and negative bias stresses with large relaxation times of 95 × 104 and 371 × 104 s, respectively, is achieved by annealing and passivation.
TL;DR: In this article, an all-inkjet-printed inverter using two p-type organic thin-film transistors (OTFTs) on a flexible plastic substrate was reported.
Abstract: We report an all-inkjet-printed inverter using two p-type organic thin-film transistors (OTFTs) on a flexible plastic substrate. Metal-organic precursor-type silver ink, poly-4-vinylphenol solution, and 6,13-bis (triisopropylsilylethynyl)-pentacene solution were used to print gate and source/drain electrodes, gate-dielectric layer, and active semiconductor layer, respectively. By optimizing fabrication conditions, we obtained OTFTs with a mobility of 0.02 cm2/V·s, an on/off ratio of 104, and a threshold voltage of -1.2 V, and inverters with good switching performance showing a gain of 7.8 at a supply voltage of VDD = -40 V .
Patent•
16 Mar 2011TL;DR: In this paper, a thin film transistor and a method of manufacturing the same are provided. But they do not specify the active layer of the transistor and do not describe the source and drain electrodes.
Abstract: A thin film transistor and a method of manufacturing the same are provided. The thin film transistor includes a first gate electrode and an active layer including a crystalline oxide semiconductor which is insulated from the first gate electrode by a first insulating layer and the active layer is arranged to overlap the first gate electrode. A source electrode is formed including at least a portion overlaps the active layer, and a drain electrode is arranged being spaced apart from the source electrode and at least a portion of the drain electrode overlaps the active layer, wherein the source electrode and the drain electrode are insulated from the first gate electrode by the first insulating layer.
TL;DR: In this paper, preseparated, high purity semiconducting carbon nanotubes hold great potential for thin-film transistors (TFTs) and integrated circuit applications.
Abstract: Due to extraordinary electrical properties, preseparated, high purity semiconducting carbon nanotubes hold great potential for thin-film transistors (TFTs) and integrated circuit applications. One ...
TL;DR: The integration of a natural protein into electronic and optoelectronic devices by using silk fibroin as a thin film dielectric in an organic thin film field-effect transistor (OFET) ad an organic light emitting transistor device (OLET) structures is presented.
TL;DR: In this paper, the role of channel layer composition on the electrical performance and stability exhibited by thin-film transistors was investigated by magnetron sputtering using ceramic targets of different compositions.
TL;DR: In this paper, a pixel circuit for AMOLED displays based on amorphous-oxide semiconductor TFTs is proposed, which consists of four switching TFT and one driving TFT.
Abstract: — Amorphous-oxide thin-film-transistor (TFT) arrays have been developed as TFT backplanes for large-sized active-matrix organic light-emitting-diode (AMOLED) displays. An amorphous-IGZO (indium gallium zinc oxide) bottom-gate TFT with an etch-stop layer (ESL) delivered excel lent electrical performance with a field-effect mobility of 21 cm2/V-sec, an on/off ratio of >108, and a subthreshold slope (SS) of 0.29 V/dec. Also, a new pixel circuit for AMOLED displays based on amorphous-oxide semiconductor TFTs is proposed. The circuit consists of four switching TFTs and one driving TFT. The circuit simulation results showed that the new pixel circuit has better performance than conventional threshold-voltage (VTH) compensation pixel circuits, especially in the negative state. A full-color 19-in. AMOLED display with the new pixel circuit was fabricated, and the pixel circuit operation was verified in a 19-in. AMOLED display. The AMOLED display with a-IGZO TFT array is promising for large-sized TV because a-IGZO TFTs can provide a large-sized backplane with excellent uniformity and device reliability.