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- 实验方案
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One-step synthesis of nitrogen-doped graphene from a sole aromatic precursor
摘要： A cheap aromatic precursor (1,10-phenanthroline) with heteroatom and planar-structure was designed to synthesize large-scale, continuous and mostly single-layer nitrogen-doped graphene (NG) films by one-step chemical vapor deposition method. The NG sheets can be obtained even at 600 ℃. The results indicated that the content and type of doped N are intensely relied on the growth temperature. Our fabrication approach provides an economic synthetic route and potentially promotes the practical application of graphene-based materials.
关键词： chemical vapor deposition,thin films,graphene,nitrogen-doped
更新于2025-09-23 15:21:01
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Sputtered cobalt doped CuO nano-structured thin films for photoconductive sensors
摘要： Pure and cobalt (Co) doped CuO thin films have been deposited by DC and AC reactive magnetron sputtering technique. The doping ratio has been controlled by the RF power of the AC sputtering unit. The sputtering power ranges from 0 to 50 W. The crystal structure of the films has been identified by X-ray diffraction. One of the peaks has been shifted toward the high diffraction angle. Energy dispersive analysis shows cationic deficiency of the pure and doped samples. Morphology of the films has been investigated by atomic force microscopy. Film roughness decrease with the increase of sputtering power. Spectrophotometry studies reveal that films darken with the increase of sputtering power. The current–voltage curves show Ohmic contacts and an enhancement in the conductivity with the increase of Co concentrations. Photoresponse measurements have shown that the film doped at 50 W is the best photodetector sensor.
关键词： photoconductive sensors,thin films,magnetron sputtering,Co doped CuO
更新于2025-09-23 15:21:01
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Thermochromism from Ultrathin Colloidal Sb <sub/>2</sub> Se <sub/>3</sub> Nanowires Undergoing Reversible Growth and Dissolution in an Amine-Thiol Mixture
摘要： Thermochromism from Ultrathin Colloidal Sb2Se3 Nanowires Undergoing Reversible Growth and Dissolution in an Amine–Thiol Mixture. Liquid-based thermochromics can be incorporated into an arbitrarily shaped container and provide a visual map of the temperature changes within its volume. However, photochemical degradation, narrow temperature range of operation, and the need for stringent encapsulation processes are challenges that can limit their widespread use. Here, a unique solution-based thermochromic comprising ultrathin colloidal Sb2Se3 nanowires in an amine–thiol mixture is introduced. The nanowires undergo reversible growth and dissolution with repeated cycles of heating and cooling between 20 and 160 °C, exhibiting intense and contrasting color changes during these processes. Furthermore, the transition temperature in which a change in color first appears can be continuously tuned over a range larger than 100 °C by introducing controlled amounts of Sn2+. The colloidal nanowire dispersion in the amine–thiol mixture retains its thermochromic properties over hundreds of temperature cycles, continuous heating at 80 °C over months, and shelf life of up to 2 years in an open container under ambient conditions. To illustrate its utility as a robust liquid thermochromic, the nanowire solution is coated onto standard filter paper and its uses as a rewritable surface by thermal scribing, as well as an inexpensive means of visualizing the temperature distribution of an anisotropically heated block are demonstrated.
关键词： tin-doped antimony selenide,colloidal nanowires,thermochromic materials,liquid-based,reversible growth and dissolution
更新于2025-09-23 15:21:01
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Decent efficiency improvement of organic photovoltaic cell with low acidic hole transport material by controlling doping concentration
摘要： Presently, poly (3, 4-ethylenedi-oxythiophene): polystyrene sulfonic acid (PEDOT:PSS) is most commonly used hole transport material (HTM) in photovoltaic (PV) cells but its higher acidity, hygroscopicity, high price have motivated people to develop a good substitute. Here, we prepare a series of PSS-doped polyaniline (PANI) with synergic (around 90%) transmittance and work function value (within 5.09-5.16 eV) varying PSS concentrations to check the possible utility as HTM in a poly (3-hexylthiophene): [6, 6]-indene-C60 bisadduct based organic photovoltaic (OPV) cell. Here, it is observed that, because of change in conductivity, the PV performance of those OPV devices is strongly dependent on the doping concentration of the HTM and, at optimized PSS concentration, PANI:PSS has higher conductivity. This facilitates better hole extraction efficiency into the PV device and results in higher short circuit current density (JSC). Therefore, the PANI:PSS-based OPV device with optimized PSS concentration exhibits same level of power conversion efficiency (PCE: 4.5±0.2 %) as a PEDOT:PSS based OPV device. Thus, a lower acidic (pH = 2.2) p-type semiconductor PANI:PSS (weight ratio = 1:1 and) can be a good alternative to highly acidic (pH = 1.7) PEDOT:PSS ( weight ratio = 1:6, Clevious Al 4083) for using as HTM in an OPV device.
关键词： Hole transport layer,Organic photovoltaic cell,Doping concentration,Poly (4-styrenesulfonic acid) doped poly (3, 4-ethylenedi-oxythiophene),Poly (4-styrenesulfonic acid) doped polyaniline
更新于2025-09-23 15:19:57
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Multifunctional behavior of Ca-doped niobium-based double perovskite for photovoltaic/solar cell devices
摘要： Smart materials of oxide ceramics are usually in the form of single- or polycrystalline. The present ceramic belongs to the polycrystalline compound of Pb1.5Ca0.5BiNbO6 which has a double perovskite structure with the general form of A1.5A′0.5BB′O6. For synthesis and characterization of the sample, a solid solution casting method, X-ray diffraction, scanning electron micrography, Infra-red spectroscopy, etc., have been utilized. Different characterization reveals that the material has a higher value of room-temperature dielectric constant remnant polarization useful for energy storage devices. Optical equities of the ceramic were further analysed by UV–Vis and PL spectroscopy analysis which reveals that the material can be useful for energy harvesting devices like photovoltaic/solar cells. The estimated thermistor parameter suggests that the material can also be useful for thermal sensor devices.
关键词： Photovoltaic/solar cell devices,Energy storage devices,Ca-doped niobium-based double perovskite,Multifunctional behavior,Thermal sensor devices
更新于2025-09-23 15:19:57
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Switchable multi-wavelength linearly-polarized lasing oscillations in a figure eight EDF laser based on spatial-mode beating by means of weakly-coupled FMF
摘要： A switchable multi-wavelength figure eight Erbium-doped fiber (EDF) laser with linearly-polarized (LP) beam generation in the C-band region is proposed and experimentally demonstrated. Spatial-mode beating occurs owing to effect of multi-mode interference in the weakly-coupled few-mode fiber (FMF). A bandpass filter of multiple specific wavelengths is created by incorporating a weakly-coupled FMF with a Sagnac fiber loop. The LP modes are generated by cascaded mode-selective couplers (MSCs), which are designed and fabricated by tapering the proposed FMF with single-mode fiber (SMF). Combination of the cascaded MSCs and a simple N × 1 optical switch is employed to switch the LP modes. In experiments, the proposed fiber laser delivers versatile lasing outputs in states of single-, dual-, triple-wavelength oscillations for LP01, LP11 and LP21 modes. We investigate the stabilities for LP01, LP11, LP21 modes in 24-min. Moreover, the mode intensity profiles, optical signal-noise ratios (OSNRs) of lasing output and slope efficiencies are also measured. The proposed fiber laser has promising applications in WDM-MDM optical fiber communication systems, optical fiber sensor systems, optical instruments and spectroscopy.
关键词： Weakly-coupled FMF,Mode selective coupler,Sagnac fiber loop,Erbium-doped fiber laser
更新于2025-09-23 15:19:57
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Designed synthesis of microstructure and defect-controlled Cu-doped ZnO-Ag nanoparticles: exploring high-efficiency sunlight-driven photocatalysts
摘要： Cu-doped ZnO nanoparticles composited with Ag were synthesized by one-step sol-gel method in this work, aiming at highly photocatalytic activity and possible application under sunlight (especially near ultraviolet and visible light regions, 300-760 nm) irradiation. Scanning electron microscopy (SEM) shows that the introduction of Cu inhibits particle aggregation. X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) reveal that Zn(Cu)O-Ag nanoparticles (CZA NPs) are composed of metallic Ag (Ag0) and Zn(Cu)O nanocrystals; while at the Cu concentration of higher than 2%, a little CuO nanocrystals appear. Transmission electron microscopy (TEM) results evidenced the well-defined formation of Zn(Cu)O-Ag and/or CuO-ZnO-Ag heterojunctions. UV–vis spectra display that the visible absorption of the samples is obviously enhanced after the Cu introduction. At a low Cu doping level (0.2%) and moderate Cu concentration (3~5%), the blue and green photoluminescence (PL) emission strength of the samples become very weak in comparison to other samples, indicative of the high separation of photogenerated electron-hole pairs. Reasonably, the higher photocatalytic degradation (complete degradation of methylene blue (MB) and methyl orange (MO) within 40 minutes under the simulated sunlight irradiation) are achieved in these cases: low Cu doping level (0.2%) and moderate Cu concentration (3~5%) in CZA NPs. Further, we checked the effects of other factors on the photocatalytic degradation for possible application. Our results suggest that one well-designed composite type such as element-doped Zn(M)O-Ag nano-heterojunction or complicated metal oxide-ZnO-Ag nanocomposites possessing suitable band structures for the separation and utilization of photo-generated carriers, will remarkably improve the photocatalytic performance of nano-ZnO under sunlight irradiation.
关键词： ZnO-Ag nanocomposites,heterojunction,sunlight irradiation,Cu-doped ZnO,photocatalytic degradation
更新于2025-09-23 15:19:57
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Q-switched fiber laser based on CdS quantum dots as a saturable absorber
摘要： In this work, a Q-switched fiber laser is demonstrated using quantum dots (QDs) cadmium sulfide (CdS) as a saturable absorber (SA) in an erbium-doped fiber laser (EDFL) system. The QD CdS is synthesized via the microwave hydrothermal assisted method and embedded into polyvinyl alcohol (PVA). The QD CdS/PVA matrix film is sandwiched in between two fiber ferrules by a fiber adapter. The generation of Q-switched fiber laser having a repetition rate, a pulse width, and a peak-to-peak pulse duration of 75.19 kHz, 1.27 μs, and 13.32 μs, respectively. The maximum output power of 3.82 mW and maximum pulse energy of 50.8 nJ are obtained at the maximum pump power of 145.9 mW. The proposed design may add to the alternative material of Q-switched fiber laser generation, which gives a high stability output performance by using quantum dots material as a saturable absorber.
关键词： CdS Quantum Dots,erbium-doped fiber laser,microwave hydrothermal assisted method,saturable absorber,Q-switched fiber laser
更新于2025-09-23 15:19:57
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Enhanced photocatalytic activity under visible light by the synergistic effects of plasmonics and Ti3+-doping at the Ag/TiO2- heterojunction
摘要： A heterojunction of plasmonic Ag particles on Ti3+-doped macro-/meso-porous TiO2 framework consisting of parallel microchannels, denoted as Ag/TiO2-x, has been fabricated by a simple microwave-assisted process employing vitamin C as the reducing agent for forming TiO2-x framework followed by photochemical deposition of Ag particles. Charge transport and recombination processes were detected through transient photocurrent responses. The visible-light photocatalytic hydrogen production rate and the apparent reaction rate constant of RhB photodegradation with 3%-Ag/TiO2-x catalyst are about 5.3 and 14.0 fold higher than those with the pristine macro-/meso-porous TiO2 framework, respectively. A mechanism based on the synergistic effects of Ag plasmonics and Ti3+-doping at the Ag/TiO2-x heterojunction is proposed, which consistently explains the high photocatalytic performance in hydrogen evolution and the improved photocatalytic decomposition of RhB under visible light. This study demonstrates the effective route to synthesize new heterojunction photocatalytic materials with multifunctional properties using low-cost and rapid microwave processes.
关键词： Macroporous/mesoporous TiO2 microchannel,Ag/TiO2-x heterojunction,Ti3+-doped TiO2,Photocatalysis,Surface plasmon resonance
更新于2025-09-23 15:19:57
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Tungsten-Doped Zinc Oxide and Indiuma??Zinc Oxide Films as High-Performance Electron-Transport Layers in Na??Ia??P Perovskite Solar Cells
摘要： Perovskite solar cells (PSCs) have attracted tremendous research attention due to their potential as a next-generation photovoltaic cell. Transition metal oxides in N–I–P structures have been widely used as electron-transporting materials but the need for a high-temperature sintering step is incompatible with flexible substrate materials and perovskite materials which cannot withstand elevated temperatures. In this work, novel metal oxides prepared by sputtering deposition were investigated as electron-transport layers in planar PSCs with the N–I–P structure. The incorporation of tungsten in the oxide layer led to a power conversion efficiency (PCE) increase from 8.23% to 16.05% due to the enhanced electron transfer and reduced back-recombination. Scanning electron microscope (SEM) images reveal that relatively large grain sizes in the perovskite phase with small grain boundaries were formed when the perovskite was deposited on tungsten-doped films. This study demonstrates that novel metal oxides can be used as in perovskite devices as electron transfer layers to improve the efficiency.
关键词： transparent metal oxide,zinc–oxynitride,perovskite solar cell,tungsten-doped InZnO
更新于2025-09-23 15:19:57