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Controllable Synthesis of One-dimensional MoO3/MoS2 Hybrid Composites with their Enhanced Efficient Electromagnetic Wave Absorption Properties
摘要： One-dimensional MoO3/MoS2 hybrid composites were synthesized via hydrothermal synthesis; and the flexible MoO3/MoS2/PVDF nanocomposites were also controllable prepared by combining the composites with polyvinylidene fluoride (PVDF) matrix. The MoO3/MoS2/PVDF hybrids with low filler content (20 wt%) exhibited distinct microwave absorption properties in the range of 2 - 18 GHz. The minimum reflection loss can reach -38.5 dB at 8.7 GHz, and the reflection loss was less than -10 dB in the frequency range from 3.03 to 11.02 GHz with an absorber thickness of 2.0 - 5.0 mm. The MoO3/MoS2/PVDF nanocomposites exhibited better absorption properties than pure MoO3 and MoS2. The possible microwave absorbing mechanism was also discussed in detail.
关键词： microwave absorption,one-dimension,nanocomposites,Molybdenum disulfide,Molybdenum oxide
更新于2025-09-23 15:23:52
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In situ thermal synthesis of molybdenum oxide nanocrystals in thermoresponsive microgels
摘要： In situ formation of nanocrystals within thermoresponsive microgels has become a significant technology in the fields of catalysis and biomedicine to fabricate multifunctional hybrid nanostructures. Usually, the room temperature or cooler was set to control the formation of nanocrystals using microgels as template in such process. Here, the relatively higher temperature was used to synthesize molybdenum oxide nanocrystals where the poly (N-vinyl caprolactam) microgels were found to work as both the stabilizer and the template. Specifically, ethanol was added in the solution of the microgels to raise their volume phase transition temperature (VPTT). Later, a modified hydrothermal process was performed at 70 °C with precursor molybdic acid concentrated in the microgels matrix through the hydrogen bond between molybdic acid and N-vinyl caprolactam units. 2D nanoflakes, nanorods and nanoplatelets of molybdenum oxide were successfully synthesized. Specially, the microgels with the crosslinked degree of 2% exhibited well hybrid with controlled sizes and ideal confine of the molybdenum oxide nanoplatelets within microgels, along with strong photoluminescence intensity. These results emphasized the feasibility of poly(N-vinyl caprolactam) microgels as template and stabilizer at high temperature and provided a novel synthesis strategies for hybrid microgels applicable in wide areas of nanotechnology from catalysis, sensing to therapy.
关键词： In situ,Poly(N-vinyl caprolactam),Hybrid microgel,Molybdenum oxide,Thermoresponsive
更新于2025-09-23 15:23:52
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Effect of thickness and post deposition annealing temperature on the structural and optical properties of thermally evaporated molybdenum oxide films
摘要： In this paper, the influence of thickness and post deposition annealing temperature on thermally evaporated molybdenum oxide films has been studied. The X-ray diffraction (XRD) and Scanning Electron Microscope (SEM) are used for crystal structural and surface morphological characterization of the films, respectively. The XRD analysis showed that the presence of α-MoO3 and MoO2 crystalline phase of the films annealed at elevated temperature ~ 250 °C after deposition. The optical constants are determined from UV–Vis transmission spectra. The optical band gap and Urbach energy is found to be temperature dependent. The refractive index of the films is estimated by the optical method as well as cross-sectional SEM image analysis. It is found that the refractive index of the films increases from ~ 1.70 to 2.03 with the decrease in film thickness from ~ 2.9 to 1.7 μm. It is also observed that the refractive index decreased from ~ 2.03 to 1.61 with the increase in post deposition annealing temperature from room temperature (RT) to ~ 250 °C. Moreover, extinction coefficient, optical conductivity, porosity, and film density are investigated as a function of source-substrate distance and post deposition annealing temperature. The Photoluminescence (PL) properties of the films are also investigated by recording spectra under the excitation wavelength at 250 nm.
关键词： Optical constants,Molybdenum oxide,X-ray diffraction,Thermal evaporation,Scanning electron microscope
更新于2025-09-23 15:22:29
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Extrinsic Defects in Crystalline MoO <sub/>3</sub> : Solubility and Effect on the Electronic Structure
摘要： The effect of six potential contaminants (Cu, In, Ga, Se, Sn and Zn) and five potential dopants (Ti, Mn, Sc, V and Y) on the electronic and optical properties of molybdenum oxide (MoO3) contact layers for solar cells was investigated using point defect analysis informed by density functional theory simulations. Of the contaminants investigated, Sn, In and Ga were found to be highly insoluble at all relevant temperatures and pressures, and therefore not a concern for solar cell manufacturing. Zn, Cu and Se exhibit some solubility, with the latter two appearing to introduce detrimental defect states near the valence band. This contamination can be avoided by increasing the O2 partial pressure during MoO3 deposition. Out of five potential aliovalent dopants, Sc, Ti and Y were disregarded due to their limited solubility in MoO3, while V was found to be highly soluble and Mn somewhat soluble. The effect of Mn and V doping was shown to be strongly dependent on the O2 partial pressure during deposition with a high pO2 favoring the formation of substitutional defects (potentially beneficial in the case of Mn doping due to the addition of defects states near the conduction band) while low pO2 favors interstitial defects.
关键词： electronic structure,solubility,solar cells,molybdenum oxide,extrinsic defects,point defect analysis,density functional theory,MoO3
更新于2025-09-23 15:21:21
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Enhancement in the performance of nanostructured CuOa??ZnO solar cells by band alignment
摘要： In this study, we investigated the effect of cobalt doping on band alignment and the performance of nanostructured ZnO/CuO heterojunction solar cells. ZnO nanorods and CuO nanostructures were fabricated by a low-temperature and cost-effective chemical bath deposition technique. The band offsets between Zn1?xCoxO (x = 0, 0.05, 0.10, 0.15, and 0.20) and CuO nanostructures were estimated using X-ray photoelectron spectroscopy and it was observed that the reduction of the conduction band offset with CuO. This also results in an enhancement in the open-circuit voltage. It was demonstrated that an optimal amount of cobalt doping could effectively passivate the ZnO related defects, resulting in a suitable conduction band offset, suppressing interface recombination, and enhancing conductivity and mobility. The capacitance–voltage analysis demonstrated the effectiveness of cobalt doping on enhancing the depletion width and built-in potential. Through impedance spectroscopy analysis, it was shown that recombination resistance increased up to 10% cobalt doping, thus decreased charge recombination at the interface. Further, it was demonstrated that the insertion of a thin layer of molybdenum oxide (MoO3) between the active layer (CuO) and the gold electrode hinders the formation of a Schottky junction and improved charge extraction at the interface. The ZnO/CuO solar cells with 10% cobalt doped ZnO and 20 nm thick MoO3 buffer layer achieved the best power conversion efficiency of 2.11%. Our results demonstrate the crucial role of the band alignment on the performance of the ZnO/CuO heterojunction solar cells and could pave the way for further progress on improving conversion efficiency in oxide-based heterojunction solar cells.
关键词： nanostructured,solar cells,X-ray photoelectron spectroscopy,power conversion efficiency,molybdenum oxide,chemical bath deposition,band alignment,CuO–ZnO,cobalt doping
更新于2025-09-23 15:21:01
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Characterization of sputtered MoOx thin films with different oxygen content and their application as back contact in CdTe solar cells
摘要： Transparent MoOx thin films with varied composition were successfully prepared by sputtering and the effects of oxygen contents on the composition stoichiometry, defect states, work functions, electrical and optical properties of MoOx films were systematically studied. These thin films were then utilized in cadmium telluride solar cells to act as back contact buffers. As compared with the CdTe solar cells with Au back contact, deteriorated performance was witnessed in those with MoOx buffers. The deterioration was demonstrated to be caused by the oxidation of CdTe surface, the large valence band offset and the insufficient work function. Finally, by optimizing the back contacts to form a CuCl/MoOx/ITO composite back contact, the efficiency was improved to 11.8%. This work demonstrates feasible approaches to prepare MoOx thin films with varied oxygen concentrations which could be easily applied to many other thin film solar cells and provide important indications in the preparation and optimization of the performance for bifacial devices.
关键词： Back contact,CdTe solar Cells,Molybdenum oxide,Magnetron sputtering
更新于2025-09-23 15:19:57
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Polyethylene glycol–modified molybdenum oxide as NIR photothermal agent and its ablation ability for HeLa cells
摘要： Molybdenum oxide, as one of the important transition metal semiconductor materials with photothermal property, has received increasing attention in the field of catalysis, sensing, energy storage, and clinical biomedicine. To improve its certain limitations such as poor biocompatibility and easy agglomeration during application as biomaterials and promote its performance as photothermal agent in biomedical fields, polyethylene glycol (PEG)–modified molybdenum oxide was synthesized and the synthesis conditions during the hydrothermal process, including the pH values and the amount of PEG added, were adjusted. Owing to the reduction function of PEG, as-obtained PEG-MoOx showed good photostability and colloidal stability, which were beneficial to its application in long-term clinical photothermal therapy. In addition, cell experiments indicated that PEG-MoOx particles exhibited low cytotoxicity and ability of photothermal killing for HeLa cells. With the increase PEG-MoOx particles in solution, the photothermal ablation ability of PEG-MoOx particles for the HeLa cells was enhanced under an 808-nm NIR laser irradiation. Hence, PEG-MoOx particles have great potential in the photothermal treatment of diseases.
关键词： Photothermal ablation,PEG,Molybdenum oxide,Near-infrared absorption,HeLa cells
更新于2025-09-19 17:15:36
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Use of Hydrogen Molybdenum Bronze in Vacuum‐Deposited Perovskite Solar Cells
摘要： Herein, the dehydration of a hydrogen molybdenum bronze (HYMoO3), converting it to molybdenum oxide (MoOX), is explored toward the development of perovskite solar cells (PSCs) for the ?rst time. H0.11MoO3 bronze is synthesized, characterized, and deposited on indium tin oxide (ITO) under different concentrations and annealing conditions for in situ conversion into MoOX with appropriate oxygen vacancies. Vacuum-deposited PSCs are fabricated using the as-produced MoOX hole injection layers, achieving a power conversion ef?ciency of 17.3% (average) for the optimal device. The latter has its stability and reproducibility tested, proving the robustness and affordability of the developed hole transport layer in PSCs.
关键词： hydrogen molybdenum bronzes,perovskite solar cells,molybdenum oxide
更新于2025-09-19 17:13:59
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Tailoring Oxidation State of Solution‐Processed MoO <sub/>3–</sub><i> <sub/>x</sub></i> Layer Using Laser‐Irradiation and Its Application in Organic Solar Cells
摘要： Solution-processed molybdenum oxide (MoO3–x) is a promising material for charge transport layer in optoelectronic devices. However, no clear relationship between oxidation state and electrical properties has been experimentally derived to guide the optimization of MoO3–x. Here, oxidation state of solution-processed MoO3–x is controlled by both a photoassisted reduction and a spontaneous reduction. The photoassisted reduction proceeds by absorbing the incoming high flux photons, resulting in oxygen vacancies. Moreover, the spontaneous reduction occurs when MoO3–x layer is in contact with indium-tin oxide (ITO) electrode and affects for several nanometers away from the interface. Thus, both the photon flux and the thickness of MoO3–x layer play a key role in determining the oxidation state. Synchrotron radiation photoelectron spectroscopy confirms a relationship that the oxidation state gradually decreases with increasing the photon flux and thinning the MoO3–x layer. As a result, at an optimized photon flux and thickness of MoO3–x layer, both high work function (>4.7 eV) and high electrical conductivity (29.1 μS cm-1) could be simultaneously obtained. These beneficial electronic properties make the solution-processed MoO3–x thin films to be an efficient hole transport layers in organic solar cells.
关键词： photoassisted reduction,molybdenum oxide,spontaneous reduction,organic solar cells,interface
更新于2025-09-19 17:13:59
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Investigation of anomalous behaviour in J-V and Suns-Voc characteristics of carrier-selective contact silicon solar cells
摘要： Process and configuration dependent carrier-selective Ag/ITO/MoOx/n-Si/LiFx/Al silicon solar cells having conversion efficiencies from 6.5% to 14.5% are investigated. Some of the cells’ anomalous characteristics in light J-V and Suns-VOC graphs are analysed by photo-induced capacitance-voltage (C-V), impedance spectroscopy (IS), and voltage- plus light-biased (white, blue and infrared) quantum efficiency (QE). Correlated analysis of cells revealed the physical origin of S-shape in light J-V and turnaround in Suns-VOC graphs. After air exposure of the MoOx film, the charge carrier accumulation at the front interface and inefficient transport through the MoOx layer have led to the anomalous features in light J-V and Suns-VOC graphs of the cell. This is reflected as an additional peak and arc in C-V and IS graphs, respectively. In the absence of the LiFx layer, the cell has shown the only turnaround in Suns-VOC graph due to the Schottky barrier. The IS analysis resolved carrier transport issues at the front junction and back contact of the cells with a distinguished response. The light-bias dependent QE analysis has confirmed the presence of carrier collection barrier at the MoOx/c-Si interface, and the Schottky contact at the back with a different response in EQE spectra.
关键词： Silicon,Turnaround,S-shape,Heterojunction,Molybdenum oxide,Solar cells,Lithium Fluoride,Carrier-selective contacts
更新于2025-09-19 17:13:59