- 标题
- 摘要
- 关键词
- 实验方案
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Incorporation of Nickel Ions to Enhance Integrity and Stability of Perovskite Crystal Lattice for High-Performance Planar Heterojunction Solar Cells
摘要： Enhancement of integrity and stability of crystal lattice are highly challenging for poly-crystalline perovskite films. In this work, a nickel (Ni) ions incorporation strategy is presented to modulate the crystal structure of CH3NH3PbI3 perovskite film. A broad range of experimental characterizations reveal that the incorporation of Ni ions can substantially eliminate the intrinsic halide vacancy defects since Ni ions have a strong preference for octahedral coordination with halide ions, resulting in improved integrity and short-range order of crystal lattice significantly. Moreover, it is also demonstrated that the stronger chemical bonding interaction between Ni ions and halide ions as well as organic group can improve the stability of perovskite material. Simultaneously, the surface morphology of perovskite thin film is also improved by incorporation of nickel ions. As a result, the 1.5% Ni-incorporated planar heterojunction perovskite solar cell exhibits a power conversion efficiency of 18.82%, which is improved by 25% compared with 14.92% for the pristine device. Simultaneously, the 1.5% Ni- incorporated device shows remarkable stability with 90% of the initial efficiency after storage in air environment for 800 h. The studies provide a new insight for metal-incorporated perovskite materials for various optoelectronic applications.
关键词： Ni ions,crystal lattice,Perovskite Solar Cells,MAPbI3,iodine vacancy defects
更新于2025-09-11 14:15:04
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IonMonger: a free and fast planar perovskite solar cell simulator with coupled ion vacancy and charge carrier dynamics
摘要： Details of an open-source planar perovskite solar cell simulator, which includes ion vacancy migration within the perovskite layer coupled to charge carrier transport throughout the perovskite and adjoining transport layers in one dimension, are presented. The model equations are discretised in space using a finite element scheme, and temporal integration of the resulting system of differential algebraic equations is carried out in MATLAB. The user is free to modify device parameters, as well as the incident illumination and applied voltage. Time-varying voltage and/or illumination protocols can be specified, e.g. to simulate current–voltage sweeps, or to track the open-circuit conditions as the illumination is varied. Typical simulations, e.g. current–voltage sweeps, only require computation times of seconds to minutes on a modern personal computer. An example set of hysteretic current–voltage curves is presented.
关键词： Perovskite solar cell,Device simulation,Drift–diffusion,Ion vacancy migration
更新于2025-09-11 14:15:04
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Controlled synthesis of nanocrystalline Nb:SrTiO <sub/>3</sub> electron transport layers for robust interfaces and stable high photovoltaic energy conversion efficiency in perovskite halide solar cells
摘要： Perovskite halides are of great attraction as efficient light absorption materials for solid-state solar cells, but the stability and photovoltaic energy conversion efficiency of perovskite solar cells (PSCs) are still limited by the interface structures and defects between their light-absorbing perovskite halides and electron transport layers (ETLs). Here, we report the ultraviolet (UV) light-induced degradation mechanism at the interfaces between perovskite halide and conventional TiO2 ETL materials, and provide a solution to overcome this drawback. UV-induced degradation is shown to be attributed to the formation of oxygen vacancies formed at the perovskite halide-ETL interface under UV light illumination, where the oxygen atoms released at the interface accelerate the decomposition of perovskite halide by inducing chemical reactions. Meanwhile, nanocrystalline SrTiO3 (STO) ETLs are revealed to be tunable in enabling high performance in PSCs under UV light illumination. Indeed, tuning the electronic structure of STO ETLs by Nb doping, in combination with the controllable removal of SrO phases segregated on the Nb-doped STO ETL surfaces, is exhibited to enable robust interface stability and stable high photovoltaic energy conversion efficiency for PSCs. Furthermore, we demonstrate that STO-based PSCs have no hysteresis due to low defect concentrations at the perovskite halide-STO ETL interfaces.
关键词： oxygen vacancy formation,electron transfer layer,perovskite oxides,photo stability,Perovskite solar cells
更新于2025-09-11 14:15:04
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Shape-controlled synthesis of golf-like, star-like, urchin-like and flower-like SrTiO3 for highly efficient photocatalytic degradation and H2 production
摘要： As a typical perovskite-type metal oxide, SrTiO3 has emerged as a prospective candidate for many fields. However, the synthesis of SrTiO3 with controlled morphology, high surface area, and enhanced photocatalytic activity are still lacking. Herein, a series of porous SrTiO3 with well-controlled morphologies including assembled nanoparticles (ANPs), golf-like particles (GLPs), star-like microspheres (SLMs), urchin-like microspheres (ULMs), and flower-like microspheres (FLMs) were successfully prepared via an ethylene glycol-water mixed solvothermal route. The ratio of VEG/VH2O play an important role in the shape-evolution during the solvothermal reaction. A comparative study of photocatalytic H2 production and photodegradation was performed, and a possible photocatalysis mechanism of SrTiO3 has been proposed. Significantly, the ULMs and FLMs photocatalysts of SrTiO3 with optimized low Pt loading amount (0.075wt.%) exhibited outstanding H2 production rates (8.21 and 7.29 mmol·g-1·h-1) due to its unique structure of high-surface area and defect-rich surface. The facile and shape-controlled synthesis of varied SrTiO3 structures is believed to be useful for the design and application of perovskite.
关键词： Mesoporous SrTiO3,Oxygen vacancy,Photocatalysis,Controlled-synthesis,Morphology evolution
更新于2025-09-11 14:15:04
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Sub-GHz linewidths ensembles of SiV centers in a diamond nano-pyramid revealed by charge state conversion
摘要： Producing nano-structures with embedded bright ensembles of lifetime-limited emitters is a challenge with potential high impact in a broad range of physical sciences. In this work, we demonstrate controlled charge transfer to and from dark states exhibiting very long lifetimes in high density ensembles of SiV centers hosted in a diamond nano-pyramid grown by chemical vapor deposition. Further, using a combination of resonant photoluminescence excitation and a frequency-selective persistent hole burning technique that exploits this charge state transfer, we could demonstrate close to lifetime-limited linewidths from the SiV centers. Such a nanostructure with thousands of bright narrow linewidth emitters in a volume much below λ3 will be useful for coherent light-matter coupling, for biological sensing, and nanoscale thermometry.
关键词： Color centers,Diamond,Silicon Vacancy centers,photoionisation,photoluminescence
更新于2025-09-11 14:15:04
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Influence of oxygen vacancy on the response properties of TiO2 ultraviolet detector
摘要： In this paper, the effect of sputtering distance between target and substrate (DTS) on the structural, morphological and optical properties of TiO2 films were investigated. X-ray diffraction (XRD) and scanning electron microscopy (SEM) revealed that crystallite size and surface morphology were strongly dependent on DTS. The X-ray photoelectron spectroscopy (XPS) results showed that obvious three peaks including C1S, Ti2p and O1s could be clearly observed and binding energy was 285, 458 and 531 eV, respectively. For each sample, four peaks at about 386, 462, 527 and 595 nm in photoluminescence (PL) spectrum were observed and produced by intrinsic recombination, F center, F+ center and electrons transferred from 3d Ti3+ states to the deep levels OH?, respectively. Finally, photoresponse properties of UV detector based on TiO2 films were further analyzed and TiO2 UV detector prepared by DTS of 80 mm showed a high responsivity of 2.02 ×10-4 A/W and photosensitivity of 32.25, also, exhibited a fast response with a rise time (τr) of 0.98 s and fall time (τf) of 3.14 s.
关键词： UV detector,oxygen vacancy,TiO2 thin films,X-ray photoelectron spectroscopy
更新于2025-09-11 14:15:04
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UNDERSTANDING Al incorporation into 4H-SiC during epitaxy
摘要： In this paper are reviewed the main reported trends of Al incorporation as a function of the main 4H-SiC epitaxial growth parameters. Al incorporation was found to be limited by its high desorption rate for all the parameters investigated. Due to the lack of a general model describing reasonably the processes of Al incorporation, the concept of surface vacancy induced incorporation was proposed and applied to explain these experimental results. In this model, Al incorporation is mainly driven by the transient formation of Si vacancies at the surface or sub-surface of terraces. It was shown that for increasing Al incorporation, one needs to improve its stability upon adsorption on Si vacancy and/or to reduce its desorption time. In this model, the transient formation of C vacancies at the surface or sub-surface (favored at low C/Si ratio) is proposed to play also a role by destabilizing the incorporated Al atoms.
关键词： Silicon Carbide,model,epitaxy,surface vacancy,Aluminum doping
更新于2025-09-10 09:29:36
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-limited sensing of static magnetic fields via fast rotation of quantum spins
摘要： Diamond-based quantum magnetometers are more sensitive to oscillating (ac) magnetic fields than static (dc) fields because the crystal impurity-induced ensemble dephasing time T ? 2 , the relevant sensing time for a dc field, is much shorter than the spin coherence time T2, which determines the sensitivity to ac fields. Here we demonstrate measurement of dc magnetic fields using a physically rotating ensemble of nitrogen-vacancy centers at a precision ultimately limited by T2 rather than T ? 2 . The rotation period of the diamond is comparable to T2 and the angle between the nitrogen-vacancy (NV) axis and the target magnetic field changes as a function of time, thus upconverting the static magnetic field to an oscillating field in the physically rotating frame. Using spin-echo interferometry of the rotating NV centers, we are able to perform measurements for over 100 times longer compared to a conventional Ramsey experiment. With modifications our scheme could realize dc sensitivities equivalent to demonstrated NV center ac magnetic field sensitivities of order 0.1 nT Hz?1/2.
关键词： spin-echo interferometry,nitrogen-vacancy centers,T2-limited sensing,dc magnetic fields,quantum magnetometers
更新于2025-09-10 09:29:36
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DFT Calculation about Oxygen Vacancy to Promote Adsorption of a CO Molecule on Single Au-Supported Titanium Dioxide
摘要： The properties and behavior of a single Au atom supported anatase TiO2(001) surface are calculated using density functional theory (DFT) methods. The structures and energies of adsorbed single Au on an anatase TiO2(001) surface with surface oxygen vacancy, as well as subsurface oxygen vacancy, are systematically determined. Initially, the surface threefold coordinated oxygen vacancy adjacent to a single Au atom, rather than the surface two-fold coordinated oxygen vacancy and subsurface threefold coordinated oxygen vacancy, results in more stability for anatase TiO2(001) surface with an Au adatom. Afterwards, the CO molecule is more strongly adsorbed on the single Au-supported TiO2(001) surface with surface threefold coordinated oxygen vacancy when comparing to other structures. This is attributed to the more negatively charged Au single-atom caused by a surface threefold coordinated oxygen vacancy presents concededly active for CO adsorption.
关键词： surface,anatase TiO2,adsorption,oxygen vacancy,Au,CO molecule
更新于2025-09-10 09:29:36
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Polyoxometalates/TiO2 Fenton-like photocatalysts with rearranged oxygen vacancies for enhanced synergetic degradation
摘要： Oxygen vacancy modulation has emerged as a prevalent strategy to improve the performance of heterogeneous catalysts. By far, the impact of oxygen vacancy rearrangement on the efficiency of Fenton-like reaction remains largely unknown. In this paper, Fe-containing polyoxometalates were coupled with defect-rearranged TiO2 to construct defective Fenton-like photocatalysts. Experimental characterizations revealed that defect rearrangement facilitated the interfacial transfer of electrons from TiO2 to polyoxometalate molecules. Fenton-like photocatalysts with rearranged defects exhibited 5 and 3.5 times higher activity for the synergetic degradation of toxic dye and 5-Sulfosalicylic acid than pristine TiO2. This enhancement was ascribed to the beneficial role of oxygen vacancy modulation for activating oxygen and H2O2 molecules into ?O2- and ?OH radicals. Our work provides new opportunities for exploring efficient Fenton-like photocatalysts for environmental remediation.
关键词： Photocatalytic reaction,Polyoxometalates,Fenton-like reaction,Titanium Dioxide,Oxygen vacancy rearrangement
更新于2025-09-10 09:29:36