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High photoluminescent InP/ZnS QDs synthesis by in situ H2S interface engineering.

Funding Information: This work was supported by the European Commission (H2020, 1D-NEON, grant agreement ID: 685758). J.M.K. and L.G.O. acknowledge the support from the U.K. Research and Innovation (EPSRC, EP/P027628/1). We thank Y. Bernstein and J. Faulkner for helping with grammar check. Funding Information: Acknowledgments Funding:ThisworkwassupportedbytheEuropeanCommission(H2020,1D-NEON,grant agreementID:685758).J.M.K.andL.G.O.acknowledgethesupportfromtheU.K.Researchand Innovation(EPSRC,EP/P027628/1).W ethankY .BernsteinandJ.Faulknerforhelpingwith grammarcheck.Authorcontributions:S.L.andJ.M.K.conceivedtheproject.S.L.,L.G.O.,P .B., R.Martins,andJ.M.K.supervisedtheproject.S.L.andH.L.developedF-PD.S.L.,Y .-W .L., G.-H.A., D.-W .S., J.I.S.,andS.C.developedF-SC.C.L.F ., A.S.,R.I.,P .B., andR.Martinsdevelopedfiber transistor.S.L.,H.L.,andS.C.developedF-LED.ThefiberdeviceswereevaluatedbyS.L.,H.W .C., D.-W .S., H.L.,S.J.,S.D.H.,S.Y .B., S.Z.,W .H.-C., Y .-H.S., X.-B.F ., T .H.L., J.-W .J., andY .K. The developmentofweavingprocesswasconductedbyS.L.,H.W .C., F .M.M., P .J., andV .G.C. Thelaser interconnectionwasdevelopedbyS.L.,H.W .C., K.U.,M.E.,andM.S.Thetextiledemonstrations werecharacterizedbyS.L.,H.W .C., D.-W .S., J.Y ., S.S.,U.E.,S.N.,A.C.,A.M.,R.Momentè,J.G.,N.D., S.M.,C.-H.K.,M.L.,A.N.,D.J.,M.C.,andY .C. ThismanuscriptwaswrittenbyS.L.andJ.M.K.and reviewed by H.W .C., D.-W .S., M.C.,L.G.O., P .B., E.F ., and G.A.J.A. All authors discussed the results andcommentedonthemanuscript.Competinginterests:Theauthorsdeclarethattheyhave nocompetinginterests.Dataandmaterialsavailability:Alldataneededtoevaluatethe conclusionsinthepaperarepresentinthepaperand/ortheSupplementaryMaterials. Publisher Copyright: Copyright © 2023 The Authors, some rights reserved. An integrated textile electronic system is reported here, enabling a truly free form factor system via textile manufacturing integration of fiber-based electronic components. Intelligent and smart systems require freedom of form factor, unrestricted design, and unlimited scale. Initial attempts to develop conductive fibers and textile electronics failed to achieve reliable integration and performance required for industrial-scale manufacturing of technical textiles by standard weaving technologies. Here, we present a textile electronic system with functional one-dimensional devices, including fiber photodetectors (as an input device), fiber supercapacitors (as an energy storage device), fiber field-effect transistors (as an electronic driving device), and fiber quantum dot light-emitting diodes (as an output device). As a proof of concept applicable to smart homes, a textile electronic system composed of multiple functional fiber components is demonstrated, enabling luminance modulation and letter indication depending on sunlight intensity. publishersversion published

Device architectures of patterned-, stacked-, and mixed-type quantum-dot light-emitting diodes (QD-LEDs) for the next-generation smart white lighting have been analyzed and optimized by computational charge transport simulation and experiments.

Large-scale printed InP RGB quantum dot (QD) light emitting diodes (QLEDs) are realised by an air-processable and stable ink with a photoinitiator (PI) mediating cross-linkage between eco-friendly QDs for next generation self-emissive display.

For the fabrication of next-generation flexible metal oxide devices, solution-based methods are considered as a promising approach because of their potential advantages, such as high-throughput, large-area scalability, low-cost processing, and easy control over the chemical composition. However, to obtain certain levels of electrical performance, a high process temperature is essential, which can significantly limit its application in flexible electronics. Therefore, this article discusses recent research conducted on developing low-temperature, solution-processed, flexible, metal oxide semiconductor devices, from a single thin-film transistor device to fully integrated circuits and systems. The main challenges of solution-processed metal oxide semiconductors are introduced. Recent advances in materials, processes, and semiconductor structures are then presented, followed by recent advances in electronic circuits and systems based on these semiconductors, including emerging flexible energy-harvesting devices for self-powered systems that integrate displays, sensors, data-storage units, and information processing functions.

sQuantum dot light-emitting diodes (QD-LEDs) are considered as competitive candidate for next-generation displays or lightings. Recent advances in the synthesis of core/shell quantum dots (QDs) and tailoring procedures for achieving their high quantum yield have facilitated the emergence of high-performance QD-LEDs. Meanwhile, the charge-carrier dynamics in QD-LED devices, which constitutes the remaining core research area for further improvement of QD-LEDs, is, however, poorly understood yet. Here, we propose a charge transport model in which the charge-carrier dynamics in QD-LEDs are comprehensively described by computer simulations. The charge-carrier injection is modelled by the carrier-capturing process, while the effect of electric fields at their interfaces is considered. The simulated electro-optical characteristics of QD-LEDs, such as the luminance, current density and external quantum efficiency (EQE) curves with varying voltages, show excellent agreement with experiments. Therefore, our computational method proposed here provides a useful means for designing and optimising high-performance QD-LED devices.

An efficient photo-annealing approach for high-performance solution-processed metal-oxide thin film transistors (TFTs) was demonstrated by using programmable pulse operation of xenon flash lamp. The flash lamp annealing (FLA) process could offer not only low-temperature (≈100° C) processing but also ultra-fast annealing speed of the order of seconds under air ambient conditions. Solution-processed amorphous indium-gallium-zinc-oxide (α-IGZO) TFTs implemented by the FLA process typically exhibited much improved electrical performance such as saturation mobility of >10.8 cm2V−11s−1, ION/IOPP of >108, and subthreshold slope of as steep as 0.24 V/dec. X-ray photoelectron spectroscopy analysis of a-IGZO films indicates that the FLA can provide sufficient activation energy for rapid formation of solid a-IGZO bonds within 30 s. The high-quality metal-oxide films achieved by an atmospheric and low temperature FLA method may represent a significant advance for scalable fabrication of flexible and printed metal-oxide electronics.

A highly reliable reverse-trapezoid-structured polydimethylsiloxane (PDMS) is demonstrated to achieve mechanically enhanced amorphous indium-gallium-zinc oxide (a-IGZO) thin-film-transistors (TFTs) for skin-compatible electronics. Finite element analysis (FEA) simulation reveals that the stress within a-IGZO TFTs can be efficiently reduced compared to conventional substrates. Based on the results, a conventional photolithography process was employed to implement the reverse-trapezoid homogeneous structures using a negative photoresist (NPR). Simply accessible photolithography using NPR enabled high-resolution patterning and thus large-area scalable device architectures could be obtained. The a-IGZO TFTs on the reverse-trapezoid-structured PDMS exhibited a maximum saturation mobility of 6.06 cm2V−1s−1 under a drain bias voltage of 10 V with minimal strain stress. As a result, the proposed a-IGZO TFTs, including stress-released architecture, exhibited highly enhanced mechanical properties, showing saturation mobility variation within 12% under a strain of 15%, whereas conventional planar a-IGZO TFTs on PDMS showed mobility variation over 10% even under a 1% strain and failed to operate beyond a 2% strain.

Among various wearable health-monitoring electronics, electronic textiles (e-textiles) have been considered as an appropriate alternative for a convenient self-diagnosis approach. However, for the realization of the wearable e-textiles capable of detecting subtle human physiological signals, the low-sensing performances still remain as a challenge. In this study, a fiber transistor-type ultra-sensitive pressure sensor (FTPS) with a new architecture that is thread-like suspended dry-spun carbon nanotube (CNT) fiber source (S)/drain (D) electrodes is proposed as the first proof of concept for the detection of very low-pressure stimuli. As a result, the pressure sensor shows an ultra-high sensitivity of ~3050 Pa&minus, 1 and a response/recovery time of 258/114 ms in the very low-pressure range of &lt, 300 Pa as the fiber transistor was operated in the linear region (VDS = &minus, 0.1 V). Also, it was observed that the pressure-sensing characteristics are highly dependent on the contact pressure between the top CNT fiber S/D electrodes and the single-walled carbon nanotubes (SWCNTs) channel layer due to the air-gap made by the suspended S/D electrode fibers on the channel layers of fiber transistors. Furthermore, due to their remarkable sensitivity in the low-pressure range, an acoustic wave that has a very tiny pressure could be detected using the FTPS.

The development of novel dielectric materials with reliable dielectric properties and low-temperature processibility is crucial to manufacturing flexible and high-performance organic thin-film transistors (OTFTs) for next-generation roll-to-roll organic electronics. Here, we investigate the solution-based fabrication of high-k aluminum oxide (Al2O3) thin films for high-performance OTFTs. Nanocluster-based Al2O3 films fabricated by highly energetic photochemical activation, which allows low-temperature processing, are compared to the conventional nitrate-based Al2O3 films. A wide array of spectroscopic and surface analyses show that ultralow-temperature photochemical activation (2O3 dielectric layer from Al-13 nanocluster-based solutions. The fabricated nanocluster-based Al2O3 films exhibit a low leakage current density (–7 A/cm2) at 2 MV/cm and high dielectric breakdown strength (>6 MV/cm). Using this dielectric layer, precisely aligned microrod-shaped 2,7-dioctyl[1]benzothieno [3,2-b][1] benzothiophene (C8-BTBT) single-crystal OTFTs were fabricated via solvent vapor annealing and photochemical patterning of the sacrificial layer.

Solution-processed oxide gate dielectrics play an important in thin-film transistors (TFTs), determining their operation voltage, device performance and power consumption. Up to now, various solution-processed oxide gate dielectrics such as aluminum oxide (Al2O3) have been surveyed, however, they generally exhibit relatively high leakage current, low dielectric constant, and hysteresis which are unfavorable for stable device operation. Here, we demonstrate solution-processed lanthanum (La)-doped Al2O3 (LAO) gate dielectrics which exhibit low leakage current density, high dielectric constant, and relatively small frequency-dependent capacitance variation. In order to find the optimal doping concentration of lanthanum in Al2O3 film, various electrical, morphological, and spectroscopic analyses were carried out. We found that the addition of lanthanum in Al2O3 film effectively reduced the defective metal hydroxide bonding states within the film and significantly enhanced its dielectric characteristics. At an optimal doping concentration of lanthanum (20 at.%), gate dielectrics showing leakage current density, dielectric constant, and breakdown field of ~10−8 A/cm2 (at 2 MV/cm), 10.5, and >5 MV/cm were obtained. Using the LAO film as a gate dielectric, solution-processed indium-zinc-oxide TFTs having a field-effect mobility of 11.9 cm2/V-s, subthreshold slope of 0.38 V/dec, and on/off ratio of 104–105 were demonstrated.

Recently, with the increased importance of low-power human-based wearable technology incorporating multiple sensory systems, room-temperature operating sensory devices are of significant interest. In this work, we demonstrate a versatile approach to realize room-temperature operable and fast recovery amorphous oxide semiconductor (AOS)-based gas sensors using multi-wavelength ultraviolet (UV) illumination. Particularly, illumination of UV light with different wavelengths enabled an amorphous indium-gallium-zinc oxide (a-IGZO) thin film transistor (FET)-based gas sensor to monitor the sensing behaviours of nitrogen dioxide (NO2) at various concentrations down to sub-ppm level. Our systematic investigation exhibited that time period taken for reacting and detaching the NO2 gas from the surface of AOS could be significantly controlled down to 32 s and several minutes, respectively, without any thermal energy. The key point of the variable properties of NO2 sensing performances in the a-IGZO FET is the generation of diverse electron-hole-pairs owing to the difference of the photonic energy applied to the sensor. Our work introduced in this research may provide a simple and efficient way for enhancing gas-sensing properties of AOS FET gas sensors by enabling programmable multi-spectral UV illumination approaches.

In this paper, we investigated the effects of crystalline structure of indium-gallium-zinc-oxide (IGZO) thin films on the electrical and photo-stability of metal-oxide thin-film transistors (TFTs). It was found that the TFTs with c-axis aligned crystalline (CAAC) IGZO channels exhibited enhanced stability under various combinations of electrical, temperature, and light-stressed conditions compared to those with amorphous (a) and nanocrystalline (nc) IGZO channels. From various electrical and spectroscopic studies, it is suggested that the low deep-level defects in CAAC-IGZO channels allowed high electrical performance and enhanced stability. Meanwhile, the a- and nc-IGZO TFTs showed relatively poor stability owing to the higher levels of deep-level defects in the channel layers. To explain the origin of the enhanced light-stability in CAAC-IGZO TFTs, we investigated the transient photo-response characteristics and it was found that the low activation energy for recombination and/or neutralization of photo-generated carriers was responsible for the enhanced stability.

Oxide dielectric materials play a key role in a wide range of high-performance solid-state electronics from semiconductor devices to emerging wearable and soft bioelectronic devices. Although several previous advances are noteworthy, their typical processing temperature still far exceeds the thermal limitations of soft materials, impeding their wide utilization in these emerging fields. Here, we report an innovative route to form highly reliable aluminum oxide dielectric films using an ultralow-temperature (60 °C) solution process with a class of oxide nanocluster precursors. The extremely low-temperature synthesis of oxide dielectric films was achieved by using low-impurity, bulky metal-oxo-hydroxy nanoclusters combined with a spatially controllable and highly energetic light activation process. It was noteworthy that the room-temperature light activation process was highly effective in dissociating the metal-oxo-hydroxy clusters, enabling the formation of a dense atomic network at low temperature. The ultralow-temperature solution-processed oxide dielectrics demonstrated high breakdown field (6 MV cm

The low-temperature electrical passivation of an amorphous oxide semiconductor (AOS) thin-film transistor (TFT) is achieved by a deep ultraviolet (DUV) light irradiation-water treatment-DUV irradiation (DWD) method. The water treatment of the first DUV-annealed amorphous indium-gallium-zinc-oxide (a-IGZO) thin film is likely to induce the preferred adsorption of water molecules at the oxygen vacancies and leads to subsequent hydroxide formation in the bulk a-IGZO films. Although the water treatment initially degraded the electrical performance of the a-IGZO TFTs, the second DUV irradiation on the water-treated devices may enable a more complete metal-oxygen-metal lattice formation while maintaining low oxygen vacancies in the oxide films. Overall, the stable and dense metal-oxygen-metal (M-O-M) network formation could be easily achieved at low temperatures (below 150 °C). The successful passivation of structural imperfections in the a-IGZO TFTs, such as hydroxyl group (OH-) and oxygen vacancies, mainly results in the enhanced electrical performances of the DWD-processed a-IGZO TFTs (on/off current ratio of 8.65 × 10(9), subthreshold slope of 0.16 V/decade, an average mobility of >6.94 cm(2) V(-1) s(-1), and a bias stability of ΔVTH < 2.5 V), which show more than a 30% improvement over the simple DUV-treated a-IGZO TFTs.

An ultra-thin and large-area skin-compatible heterogeneous organic/metal-oxide photosensor array is demonstrated which is capable of sensing and boosting signals with high detectivity and signal-to-noise ratio. For the realization of ultra-flexible and high-sensitive heterogeneous photosensor arrays on a polyimide substrate having organic sensor arrays and metal-oxide boosting circuitry, solution-processing and room-temperature alternating photochemical conversion routes are applied.

Conventional von Neumann–based computing systems have inherent limitations such as high hardware complexity, relatively inferior energy efficiency, and low bandwidth. As an alternative, neuromorphic computation is emerging as a platform for next‐generation artificial intelligence computing systems due to their potential advantages such as highly energy‐efficient computing, robust learning, fault tolerance, and parallel processing. Moreover, to further enhance the energy efficiency and processing speed, photonic‐based neuromorphic systems have gathered significant interest in the past few years. Herein, the recent progress and development of optoelectronic and all‐optical neuromorphic devices is summarized, focusing on their structures, materials, and potential applications. Particularly, for optoelectronic neuromorphic devices, devices with planar and vertical structures are described along with their key strategies in materials and device structures. Next, all‐optical memory and neuromorphic devices for neuromorphic computing are reviewed. Finally, the applications of optoelectronic neuromorphic devices are discussed for their potential utilization in neuromorphic computing systems.

The increasing interest in flexible and wearable electronics has demanded a dramatic improvement of mechanical robustness in electronic devices along with high-resolution implemented architectures. In this study, a site-specific stress-diffusive manipulation is demonstrated to fulfill highly robust and ultraflexible amorphous indium-gallium-zinc oxide (a-IGZO) thin-film transistors (TFTs) and integrated circuits. The photochemically activated combustion sol-gel a-IGZO TFTs on a mesa-structured polyimide show an average saturation mobility of 6.06 cm2 V-1 s-1 and a threshold voltage of -0.99 V with less than 9% variation, followed by 10 000 bending cycles with a radius of 125 μm. More importantly, the site-specific monolithic formation of mesa pillar-structured devices can provide fully integrated logic circuits such as seven-stage ring-oscillators, meeting the industrially needed device density and scalability. To exploit the underlying stress-diffusive mechanism, a physical model is provided by using a variety of chemical, structural, and electrical characterizations along with multidomain finite-element analysis simulation. The physical models reveal that a highly scalable and robust device can be achieved via the site-specific mesa architecture, by enabling generation of multineutral layers and fine-tuning the accumulated stresses on specific element of devices with their diffusion out into the boundary of the mesa regions.

A new strategy is reported to achieve high-mobility, low-off-current, and operationally stable solution-processable metal-oxide thin-film transistors (TFTs) using a corrugated heterojunction channel structure. The corrugated heterojunction channel, having alternating thin-indium-tin-zinc-oxide (ITZO)/indium-gallium-zinc-oxide (IGZO) and thick-ITZO/IGZO film regions, enables the accumulated electron concentration to be tuned in the TFT off- and on-states via charge modulation at the vertical regions of the heterojunction. The ITZO/IGZO TFTs with optimized corrugated structure exhibit a maximum field-effect mobility >50 cm2 V-1 s-1 with an on/off current ratio of >108 and good operational stability (threshold voltage shift

Chalco-gel–based metal-chalcogenide semiconductors and scalable high-performance electronic devices were demonstrated., We report a general strategy for obtaining high-quality, large-area metal-chalcogenide semiconductor films from precursors combining chelated metal salts with chalcoureas or chalcoamides. Using conventional organic solvents, such precursors enable the expeditious formation of chalco-gels, which are easily transformed into the corresponding high-performance metal-chalcogenide thin films with large, uniform areas. Diverse metal chalcogenides and their alloys (MQx: M = Zn, Cd, In, Sb, Pb; Q = S, Se, Te) are successfully synthesized at relatively low processing temperatures (107 and good operational stability (threshold voltage shift < 0.5 V at a positive gate bias stress of 10 ks). In addition, metal chalcogenide–based phototransistors with a photodetectivity of >1013 Jones and seven-stage ring oscillators operating at a speed of ~2.6 MHz (propagation delay of < 27 ns per stage) are demonstrated.

In this paper, we demonstrate high-performance and hysteresis-free solution-processed indium–gallium–zinc oxide (IGZO) thin-film transistors (TFTs) and high-frequency-operating seven-stage ring oscillators using a low-temperature photochemically activated Al2O3/ZrO2 bilayer gate dielectric. It was found that the IGZO TFTs with single-layer gate dielectrics such as Al2O3, ZrO2, or sodium-doped Al2O3 exhibited large hysteresis, low field-effect mobility, or unstable device operation owing to the interfacial/bulk trap states, insufficient band offset, or a substantial number of mobile ions present in the gate dielectric layer, respectively. To resolve these issues and to explain the underlying physical mechanisms, a series of electrical analyses for various single- and bilayer gate dielectrics was carried out. It is shown that compared to single-layer gate dielectrics, the Al2O3/ZrO2 gate dielectric exhibited a high dielectric constant of 8.53, low leakage current density (∼10–9 A cm–2 at 1 MV cm–1), and sta...

Despite intensive research on photochemical activation of sol–gel metal oxide materials, the relatively long processing time and lack of deep understanding of the underlying chemical courses have limited their broader impact on diverse materials and applications such as thin-film electronics, photovoltaics, and catalysts. Here, in-depth studies on the rapid photochemical activation of diverse sol–gel oxide films using various spectroscopic and electrical investigations for the underlying physicochemical mechanism are reported. Based on the exhaustive chemical and physical analysis, it is noted that deep ultraviolet-promoted rapid film formation such as densification, polycondensation, and impurity decomposition is possible within 5 min via in situ radical-mediated reactions. Finally, the rapid fabrication of all-solution metal oxide thin-film-transistor circuitry, which exhibits stable and reliable electrical performance with a mobility of >12 cm2 V−1 s−1 and an oscillation frequency of >650 kHz in 7-stage ring oscillator even after bending at a radius of

Incorporation of Zr into an AlOx matrix generates an intrinsically activated ZAO surface enabling the formation of a stable semiconducting IGZO film and good interfacial properties. Photochemically annealed metal-oxide devices and circuits with the optimized sol-gel ZAO dielectric and IGZO semiconductor layers demonstrate the high performance and electrically/mechanically stable operation of flexible electronics fabricated via a low-temperature solution process.

Here, we report static and dynamic water motion-induced instability in indium-gallium-zinc-oxide (IGZO) thin-film transistors (TFTs) and its effective suppression with the use of a simple, solution-processed low-k (e ∼ 1.9) fluoroplastic resin (FPR) passivation layer. The liquid-contact electrification effect, in which an undesirable drain current modulation is induced by a dynamic motion of a charged liquid such as water, can cause a significant instability in IGZO TFTs. It was found that by adopting a thin (∼44 nm) FPR passivation layer for IGZO TFTs, the current modulation induced by the water-contact electrification was greatly reduced in both off- and on-states of the device. In addition, the FPR-passivated IGZO TFTs exhibited an excellent stability to static water exposure (a threshold voltage shift of +0.8 V upon 3600 s of water soaking), which is attributed to the hydrophobicity of the FPR passivation layer. Here, we discuss the origin of the current instability caused by the liquid-contact electrification as well as various static and dynamic stability tests for IGZO TFTs. On the basis of our findings, we believe that the use of a thin, solution-processed FPR passivation layer is effective in suppressing the static and dynamic water motion-induced instabilities, which may enable the realization of high-performance and environment-stable oxide TFTs for emerging wearable and skin-like electronics.

Although transparent conducting oxides (TCOs) have played a key role in a wide range of solid-state electronics from conventional optoelectronics to emerging electronic systems, the processing temperature and conductivity of solution-processed materials seem to be far exceeding the thermal limitations of soft materials and insufficient for high-perfomance large-area systems, respectively. Here, we report a strategy to form highly conductive and scalable solution-processed oxide materials and their successful translation into large-area electronic applications, which is enabled by photoassisted postfunctionalization at low temperature. The low-temperature fabrication of indium-tin-oxide (ITO) thin films was achieved by using photoignited combustion synthesis combined with photoassisted reduction process under hydrogen atmosphere. It was noteworthy that the photochemically activated hydrogens on ITO surface could be triggered to facilitate highly crystalline oxygen deficient structure allowing significant increase of carrier concentration and mobility through film microstructure modifications. The low-temperature postfunctionalized ITO films demonstrated conductivity of1607 S/cm and sheet resistance of104 Ω/□ under the process temperature of less than 300 °C, which are comparable to those of vacuum-deposited and high-temperature annealed ITO films. Based on the photoassisted postfunctionalization route, all-solution-processed transparent metal-oxide thin-film-transistors and large-area integrated circuits with the ITO bus lines were demonstrated, showing field-effect mobilities of6.5 cm

In this paper, we demonstrate high mobility solution-processed metal-oxide thin-film transistors (TFTs) by using a high-frequency-stable ionic-type hybrid gate dielectric (HGD). The HGD gate dielectric, a blend of sol-gel aluminum oxide (AlOx) and poly(4-vinylphenol) (PVP), exhibited high dielectric constant (epsilon similar to 8.15) and high-frequency-stable characteristics (1 MHz). Using the ionic-type HGD as a gate dielectric layer, an minimal electron-double-layer (EDL) can be formed at the gate dielectric/InOx interface, enhancing the field-effect mobility of the TFTs. Particularly, using the ionic-type HGD gate dielectrics annealed at 350 degrees C, InOx TFTs having an average field-effect mobility of 16.1 cm(2)/Vs were achieved (maximum mobility of 24 cm(2)/Vs). Furthermore, the ionic-type HGD gate dielectrics can be processed at a low temperature of 150 degrees C, which may enable their applications in low-thermal-budget plastic and elastomeric substrates. In addition, we systematically studied the operational stability of the InOx TFTs using the HGD gate dielectric, and it was observed that the HGD gate dielectric effectively suppressed the negative threshold voltage shift during the negative-illumination-bias stress possibly owing to the recombination of hole carriers injected in the gate dielectric with the negatively charged ionic species in the HGD gate dielectric.

The combination of a neuromorphic architecture and photonic computing may open up a new era for computational systems owing to the possibility of attaining high bandwidths and the low-computation-power requirements. Here, the demonstration of photonic neuromorphic devices based on amorphous oxide semiconductors (AOSs) that mimic major synaptic functions, such as short-term memory/long-term memory, spike-timing-dependent plasticity, and neural facilitation, is reported. The synaptic functions are successfully emulated using the inherent persistent photoconductivity (PPC) characteristic of AOSs. Systematic analysis of the dynamics of photogenerated carriers for various AOSs is carried out to understand the fundamental mechanisms underlying the photoinduced carrier-generation and relaxation behaviors, and to search for a proper channel material for photonic neuromorphic devices. It is found that the activation energy for the neutralization of ionized oxygen vacancies has a significant influence on the photocarrier-generation and time-variant recovery behaviors of AOSs, affecting the PPC behavior.

Solution-processed organic single crystals with high carrier mobility have been actively investigated for diverse applications such as displays, sensors, and next generation electronics on a flexible platform. However, the lack of precise alignment and growth control of organic single crystals impedes the widespread adoption of organic materials in an industrial perspective. Here, a photochemical modification approach is reported tailoring the solubility and molecular diffusivity of polymeric sacrificial layer and sequential batch-type vapor annealing to implement high-performance (average saturation mobility: 8.01 cm2 V-1 s-1 ) organic single-crystal thin film transistors with large channel width including multiple aligned single crystals. Additionally, the mechanical properties of the organic single crystals are systematically investigated with extreme strain conditions such as bending radius of 150 μm.