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Organic-inorganic hybrid light-emitting devices have garnered significant attention in the last few years due to their potential. These devices integrate the superior electron mobility of inorganic semiconductors with the remarkable optoelectronic characteristics of organic semiconductors. The inquiry focused on analyzing the optical and electrical properties of a light-emitting heterojunction that combines p-type GaN with organic materials (PEDOT, PSS, and PMMA). This heterojunction is an organic-inorganic hybrid. The procedure entailed utilizing a spin-coating technique to apply a layer of either poly(methyl methacrylate) (PMMA) or a mixture of PMMA and poly(3,4ethylenedioxythiophene)-poly(styrene sulfonate) (PEDOT: PSS) onto an indium tin oxide (ITO) substrate. Subsequently, different Nd:YAG laser pulses (200, 250, and 300 pulses) were used to administer a GaN inorganic layer onto the prepared organic layer using a pulsed laser deposition approach. Subsequently, the thermal evaporation technique was employed to deposit an aluminum electrode on the top of the organic and inorganic layers, while laser pulses were fine-tuned for optimal performance. The Hall effect investigation verifies the p-type conductivity of the GaN material. The electroluminescence studies confirmed the production of blue light by the GaN-based devices throughout a range of voltage situations, spanning from 45 to 72 V.

RESUMEN

Despite numerous studies on broadband photodetectors, the problematic query that remains unaddressed is the limited photoresponsivity while broadening the spectral regime. Here, for the first time, a rational design of a hybrid 1D CdSe nanobelt/2D PbI2 flake heterojunction device is constructed, which substantially boosts the photocurrent while significantly attenuating the dark current, resulting in improved photodetector figures-of-merit. Thanks to the excellent quality of the nanobelt/flake and built-in electric field at the CdSe/PbI2 interface heterojunction, photogenerated carriers are promptly segregated and more photoexcitons are accumulated by the respective electrodes, enabling a high responsivity of ∼106 A/W, making this one of the highest values among similar reported hybrid heterojunction photodetectors, together with a large linear dynamic range, superior sensitivity, excellent detectivity and external quantum efficiency, an ultrafast response, and a broadband spectral response range. The similar 1D/2D hybrid heterojunction device architecture assembled on the flexible polyimide tape substrate exhibits excellent folding endurance and mechanical, flexural, and long-term environmental stability. The present device architecture and robust operational stability in an ambient environment reveals that the combination of the present 1D/2D hybrid heterojunction has incredible potential for future flexible photoelectronic devices.

RESUMEN

Ethanol is a harmful volatile organic compound (VOC) for human health. Currently, zinc oxide (ZnO) is one of the most popular metal oxide semiconductors for VOCs detection but suffering from a lack of selectivity, poor response, and slow response/recovery speeds. Herein, we successfully synthesized the ZnO/Ti3C2Txnanocomposites via a facile hydrothermal method, in which ZnO nanoparticles were uniformly grown on two-dimensional (2D) Ti3C2Txnanosheets. As a result, the ZnO/Ti3C2Txnanocomposites showed a significant improvement in the ethanol-sensing performance, when it compared to the pure ZnO and Ti3C2Txsamples. In particular, ZnO doped with 5 mg of Ti3C2Txshowed an ultra-high response (79) to 100 ppm ethanol, a short response/recovery time (22 s/34 s to 50 ppm ethanol), a low limit of detection (1 ppm) and a long-term stability. The excellent ethanol sensing properties are mainly attributed to the coupling effect between ZnO and Ti3C2Txof composites. The ZnO nanoparticles are uniformly distributed on the 2D Ti3C2Txplatform, which can provide more gas adsorption sites. Simultaneously, the presence of hybrid heterojunctions further enhances the response in the sensing process.

RESUMEN

Nitrogen dioxide (NO2) gas has emerged as a severe air pollutant that causes damages to the environment, human life and global ecosystems etc. However, the currently available NO2 gas sensors suffers from insufficient selectivity, sensitivity and long response times that impeding their practical applicability for room temperature (RT) gas sensing. Herein, we report a high performance langasite (LGS) based surface acoustic wave (SAW) RT NO2 gas sensor using 2-dimensional (2D) g-C3N4@TiO2 nanoplates (NP) with {001} facets hybrid nanocomposite as a chemical interface. The g-C3N4@TiO2 NP/LGS SAW device showed a significant negative frequency shift (∆f) of ~19.8 kHz which is 2.4 fold higher than that of the pristine TiO2 NP/LGS SAW sensor toward 100 ppm of NO2 at RT. In addition, the hybrid SAW device fascinatingly exhibited a fast response/recovery time with a low detection limit, high selectivity, and an effective long term stability toward NO2 gas. It also exhibited an enhanced and robust negative frequency shifts under various relative humidity conditions ranging from 20% to 80% for 100 ppm of NO2 gas. The high performance of the g-C3N4 @TiO2 NP/LGS SAW gas sensor can be attributed to the enhanced mass loading effect which was assisted by the large surface area, oxygen vacancies, OH and amine functional groups of the n-n hybrid heterojunction of g-C3N4@TiO2 NP that provide abundant active sites for the adsorption and diffusion of NO2 gas molecules. These results emphasize the significance of the integration of 2D materials with metal oxides for SAW based RT gas sensing technology holds great promise in environmental protection.

RESUMEN

Hybrid heterojunction solar cells (HHSCs) using crystalline Si nanowires (SiNWs) as the absorber and conducting polymer poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) as the hole-selective transport layer (HTL) show great potential in both low-cost and high-power conversion efficiency (PCE). However, due to the poor wettability of the PEDOT:PSS solution on SiNWs, conformal coverage of PEDOT:PSS on SiNWs is not easy to achieve. Here, an effective method was developed to decrease the surface tension of the PEDOT:PSS and increase the wettability between PEDOT:PSS and SiNWs by incorporating organosilane into the PEDOT:PSS solution. Two kinds of organosilanes including tetramethoxysilane (TMOS) and vinyltrimethoxysilane (VTMO) were selected as the additives. The surface passivation quality of the SiNWs was dramatically enhanced. The HHSCs utilizing VTMO as the additive show a higher open circuit voltage and higher PCE compared with the TMOS adding ones. By spin-coating Ag nanowires onto the PEDOT:PSS HTL layer and using spin-coated phenyl-C61-butyric acid methyl ester as the electron-selective transport layer, a champion PCE up to 18.12% and a fill factor of 80.1% have been achieved on the full solution processed PEDOT:PSS/n-type SiNWs HHSCs. The findings provide a simple and promising method to achieve high-performance PEDOT:PSS/SiNWs HHSCs.

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The construction of manufacturable, stable, high-quality metal/semiconductor junction structures is of fundamental importance to implement higher-level devices and circuit systems. Owing to the unique features of two-dimensional (2D) materials, namely, that intralayer atoms are covalently bonded, whereas interlayer atoms are held together by weak attractive interactions, there are several studies on the fabrication and identification of the peculiar properties of various 2D heterostructures. However, large-scale 2D lateral metal/semiconductor junction structures with acceptable levels of manufacturability and quality have not yet been demonstrated, which is among the critical technological hurdles to overcome for the realization of 2D material-based electronic and photonic devices. This paper reports the fabrication of a manufacturable large-scale metal (Mo2C)/semiconductor (MoS2) junction via selective synthetic integration and a lithographically patterned SiO2 masking layer. It is demonstrated that whereas chemical conversion to Mo2C occurs in the exposed chemical vapor deposition-grown MoS2 part, the MoS2 layer under the SiO2 masking layer is protected from chemical conversion, so that a scalable Mo2C/MoS2 heterostructure is integrated down to nanometer-scale dimensions. Excellent contact resistance of 2.1 kΩ·µm is achieved from this lateral junction structure, providing a manufacturable and highly stable metal/semiconductor building block for real implementation of 2D material-based nanoscale device integration.

RESUMEN

Just as biological synapses provide basic functions for the nervous system, artificial synaptic devices serve as the fundamental building blocks of neuromorphic networks; thus, developing novel artificial synapses is essential for neuromorphic computing. By exploiting the band alignment between 2D inorganic and organic semiconductors, the first multi-functional synaptic transistor based on a molybdenum disulfide (MoS2 )/perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) hybrid heterojunction, with remarkable short-term plasticity (STP) and long-term plasticity (LTP), is reported. Owing to the elaborate design of the energy band structure, both robust electrical and optical modulation are achieved through carriers transfer at the interface of the heterostructure, which is still a challenging task to this day. In electrical modulation, synaptic inhibition and excitation can be achieved simultaneously in the same device by gate voltage tuning. Notably, a minimum inhibition of 3% and maximum facilitation of 500% can be obtained by increasing the electrical number, and the response to different frequency signals indicates a dynamic filtering characteristic. It exhibits flexible tunability of both STP and LTP and synaptic weight changes of up to 60, far superior to previous work in optical modulation. The fully 2D MoS2 /PTCDA hybrid heterojunction artificial synapse opens up a whole new path for the urgent need for neuromorphic computation devices.

Asunto(s)

Materiales Biomiméticos , Transistores Electrónicos , Anhídridos , Biomimética , Disulfuros , Diseño de Equipo , Humanos , Molibdeno , Inhibición Neural , Redes Neurales de la Computación , Plasticidad Neuronal , Neuronas/fisiología , Perileno/análogos & derivados , Sinapsis/fisiología , Transmisión Sináptica

RESUMEN

The interface at the metal oxide-carbon hybrid heterojunction is the source to the well-known "synergistic effect" in catalysis. Understanding the structure-function properties is key for designing more advanced catalyst-support systems. Using a model MnIII-O x single-layer catalyst on carbon, we herein report a full elucidation to the catalytic synergism at the hybrid heterojunction in the oxygen reduction reaction (ORR). The successful fabrication of the single-layer catalyst from bottom-up is fully characterized by the X-ray absorption fine structure and high-resolution transmission electron microscopy. For oxygen electrocatalysis over this model hybrid heterostructure, our results, from both theory and experiment, show that the synergistic ORR truly undergoes a cooperated two-step electrocatalysis with catalytic promotion (Δ Eonset = 60 mV) near the heterojunction and over the single-layer catalyst through an interfacial electronic interplay, rather than an abstruse transition towards a one-step dissociative pathway. Finally, we report a superior peroxide-reducing activity of 432.5 mA cm-2 mg(M)-1 over the MnIII-O x single-layer.