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Facial construction of defected NiO/TiO2 with Z-scheme charge transfer for enhanced photocatalytic performance
摘要： Here we report a defected NiO/TiO2 composite (NiO/TiO2-OV) fabricated by a two-step hydrothermal method with the followed one-step calcination, which induced the in situ generation of Ti3+ and oxygen vacancies, coupled with the construction of a direct Z-scheme band structure. The NiO/TiO2-OV catalyst exhibited a substantially improved performance in the photodegradation of organic pollutant and photocatalytic hydrogen evolution reaction (HER). The sensitization by narrow bandgap semiconductor of NiO enhanced the light response of catalysts. More importantly, the intrinsic defects, the Ti3+ and oxygen vacancies, acted as the mid-gap state in TiO2, and resulted in the direct Z-scheme charge transfer between the Ti3+/oxygen vacancies state and the valance band (VB) of NiO to suppress the recombination of photogenerated electrons and holes. Meanwhile, the realignment of band structure caused by constructing NiO/TiO2 heterojunction made the photogenerated carries more active in the photocatalytic reduction and oxidation reactions.
关键词： Z-scheme charge transfer,NiO/TiO2 hybrid,Photocatalysis,Surface defects,Self-doping of Ti3+
更新于2025-09-09 09:28:46
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Microstructural, optical, and electrical characteristics of Ni/C doped BST thin films
摘要： In the present work the effect of simultaneous doping of carbon and nickel on the microstructural, optical, and electrical properties of barium strontium titanate (BST) is investigated. Thin films of BST were prepared by the sol-gel method in six different compositions ((Ba0.6Sr0.4)(NixCyTi1-x-y)O3): x = y = 0.00 (BST), x = 0.04 y = 0.00 (BST4N), x = 0.04 y = 0.01 (BST4N-1C), x = 0.04 y = 0.02 (BST4N-2C), x = 0.04 y = 0.03 (BST4N-3C), and x = y = 0.04 (BST4N-4C). Structural features and chemical bonds of the films were studied by TGA/DSC, XRD, FT-IR, and FE-SEM. The electrical and optical properties of the films were analysed by impedance spectroscopy and UV–VIS spectroscopy. The results show that addition of Ni and C leads to Ti4+-Ni2+ and Ti4+-C4+ replacements, respectively. These replacements lead to a gradual increase in the band gap energy; from 3.15 eV for BST to 3.44, 3.5, 3.66, 3.73 and 3.76 eV for BST4N, BST4N-1C, BST4N-2C, BST4N-3C, and BST4N-4C, respectively. In contrast, the dielectric loss decreases significantly from 0.055 for BST to 0.031, 0.033, 0.03, 0.022 and 0.01 for BST4N, BST4N-1C, BST4N-2C, BST4N-3C, and BST4N-4C, respectively. At the same time, the quality factor Qf (1/ tanδ) increases substantially from 15 for BST to 32, 30, 33, 44 and 87 for BST4N, BST4N-1C, BST4N-2C, BST4N-3C, and BST4N-4C, respectively. In contrast, the frequency dependence of the capacity decreases in comparison to un-doped BST. Among all films, the BST4N-4C had the highest figure of merit (FOM), least dielectric loss, and very low frequency-dependence, making it the best candidate for tuneable device applications.
关键词： Ion doping,Sol-gel,Thin-film,BaSrTiO3,Dielectric properties,Optical properties
更新于2025-09-09 09:28:46
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Degradation of Rhodamine B Under Visible-Light by Cu-Doped ZnAl Layered Double Hydroxide
摘要： The Cu-doped ZnAl layered double hydroxides (LDH) were papered by coprecipitation. The prepared samples were characterized by mutiple techniques including X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area, scanning electronic microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and UV-vis diffuse-re?ectance spectroscopy (UV-vis DRS). The doping of Cu2+ into the LDH sheets results in formation of the distorted CuO6 octahedrons which contribute for the excitation of electrons under visible light. The doped Cu2+ also serves as photo-generated charges separator and improves the visible-light-driven photocatalytic activity of ZnAl LDH. A degradation mechanism based on the hydroxyl radical as the active species was proposed.
关键词： RhB Degradation,Visible Light,Copper-Doping,Layered Double Hydroxides
更新于2025-09-09 09:28:46
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Optical study of p-doping in GaAs nanowires for low-threshold and high-yield lasing
摘要： Semiconductor nanowires suffer from significant non-radiative surface recombination, however, heavy p-type doping has proven to be a viable option to increase the radiative recombination rate and hence quantum efficiency of emission, allowing demonstration of room-temperature lasing. Using a large-scale optical technique, we have studied Zn-doped GaAs nanowires to understand and quantify the effect of doping on growth and lasing properties. We measure the non-radiative recombination rate (knr) to be (0.14 ± 0.04) ps?1 by modelling the internal quantum efficiency (IQE) as a function of doping level. By applying a correlative method, we identify doping and nanowire length as key controllable parameters determining lasing behavior, with reliable room-temperature lasing occurring for p ?3 × 1018 cm?3 and lengths ? 4 μm. We report a best-in-class core-only near-infrared nanowire lasing threshold of ～ 10 μJ cm?2 , and using a data-led filtering step, we present a method to simply identify sub-sets of nanowires with over 90% lasing yield.
关键词： Doping,PL,III-V Nanowire lasers
更新于2025-09-09 09:28:46
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A dynamic bipolar electrode array for visualized screening of electrode materials in light-emitting electrochemical cells
摘要： Charge injection at a metal/semiconductor interface is of paramount importance for many chemical and physical processes. The dual injection of electrons and holes, for example, is necessary for electroluminescence in organic light-emitting devices. In an electrochemical cell, charge transfer across the electrode interface is responsible for redox reactions and faradic current flow. In this work, we use polymer light-emitting electrochemical cells (PLECs) to visually assess the ability of metals to inject electronic charges into a luminescent polymer. Silver, aluminum or gold micro-discs are deposited between the two driving electrodes of the PLEC in the form of a horizontal array. When the PLEC is polarized, the individual discs functioned as bipolar electrodes (BPEs) to induce redox p- and n-doping reactions at their extremities, which are visualized as strongly photoluminescence-quenched growth in the luminescence polymer. The three metals initially generate highly distinct doping patterns that are consistent with differences in their work function. Over time, the doped regions continue to grow in size. Quantitative analysis of the n/p area ratio reveals an amazing convergence to a single value for all 39 BPEs, regardless of their metal type and large variation in the size of individual doped areas. We introduce the concept of a dynamic BPE, which transforms from an initial metal disc of fixed size to one that is a composite of p- and n-doped polymer joined by the initial metallic BPE. The internal structure of the dynamic BPE, as measured by the n/p area ratio, reflects only the properties of the mixed conductor of the PLEC active layer itself when the area ratio converges.
关键词： electrochemical doping,bipolar electrodes,light-emitting electrochemical cells,work function,electrode screening
更新于2025-09-09 09:28:46
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Impact of Mg doping contents on the n-type and p-type ZnO by first-principles calculations
摘要： The effect of Mg doping on the electrical properties of pure ZnO and Al-doped ZnO, Al-2N co-doped ZnO have been investigated. It was found that after Mg doping, the bandgap values increased with the increase of Mg doping concentration. After Mg was doped into the Al doped ZnO structure, it was found that as the Mg doping contents increased, the CBM gradually moved toward the higher energy direction, the VBM gradually moved toward the lower energy direction, resulting in an increase of the band gap. After Mg was doped into the Al-2N co-doped structure, the band structure of Al-2N-Mg co-doped ZnO had a shallow acceptor level, indicating that the incorporation of Mg is beneficial for the electrical properties of p-type ZnO. The absorption of Al-2N-Mg co-doped ZnO is higher than that of Al-2N co-doped ZnO in the range of the visible region, which has a significant meaning for the applications on solar cell devices.
关键词： optical properties,band structure,first-principles,p-type ZnO,Mg doping
更新于2025-09-09 09:28:46
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Chemical Bath Deposition of Undoped and Bi-doped n-Cu2Se Films and their Optoelectrical Properties
摘要： Introduction: The effluence of Bi3+ doping on the microstructure and property of the undoped and Bi3+-doped Cu2Se films deposited by chemical bath deposition were studied. Methods: The films showed average UV-visible transmittances of ~73.29-84.10 % that increased with increasing Bi3+ content. The optical bandgaps calculated from optical spectra increased with increasing Bi3+ content. Strong bandgap emission at ~629 nm was also observed. Moreover, the films had actual Se/Cu<2 and n-type conductive. Result: The sheet resistance of ~4.13-96.44×10-3 Ω·cm first decreased and then increased with the increase in Bi content. Conclusion: Various optical constants of the films were estimated with the UV-visible light spectra.
关键词： film deposition,optical property,electrical property,doping,Cu2Se,semiconductor
更新于2025-09-09 09:28:46
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8.2: <i>Invited Paper:</i> Research on the Effects of Different Doping Methods on Top-Gate IGZO TFT
摘要： By N2O/N2/O2 doped the active layer and He/Ar/Al/SiNx doped the S/D of Top-Gate IGZO TFT, we have summarized the effects of different doping modes on the properties of Top-Gate IGZO TFT, including doping the active layer of Top-Gate IGZO TFT with N2O can obviously improve the electrical uniformity of devices , and doping the S/D of Top-Gate IGZO TFT with aluminum(Al) can significantly improve the NBTIS/ PBTIS of devices, etc. By optimizing the doping method, we have fabricated a device with both good electrical uniformity and good electrical properties, with threshold voltage shift (ΔVth ) of 18 points less than 1V, Mobility=8.6 cm2/V.S,Subthreshold Swing(SS) =0.26 V/dec ,Threshold Voltage（Vth）=2.9V ,ΔVth=1.54 V (NBTIS, Bias=-30V,T=80 ℃ ,Backlight=4500Nit,2000S,W/L=6/12),ΔVth= 5.28V(PBTIS,Bias=+30V，T=80℃, Backlight=4500Nit, 2000S， W/L=6/12) .
关键词： Active layer,Ion Bombardment,Top-Gate IGZO TFT,S/D,H* Diffusion,Defect state,Doping,Oxygen Concentration,Al Seize oxygen
更新于2025-09-09 09:28:46
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Investigation of half-metallic ferromagnetism in hafnium and tantallum doped NiO for spintronic applications: A DFT study
摘要： Full Potential Linearised Augmented Plane Wave (FP-LAPW) method was used to investigate the electronic and magnetic properties of NiO doped with Hf and Ta within the frame work of density functional theory(DFT). NiO is found to be stable in rock salt structure. NiO shows metallic character for the lattice constant of 4.155?. Doping Hf and Ta in the metallic super cell of NiO separately in the doping concentration of 12.5%, the compounds Hf0.125Ni0.875O and Ta0.125Ni0.875O are formed. These compounds of Hf0.125Ni0.875O and Ta0.125Ni0.875O are found to be stable in the ferromagnetic phase. The density of states and band structure plots predict that these compounds exhibit half metallic character with formation of energy gap in one of the spins at the Fermi level. The total spin magnetic moments found in these compounds are 12.00689 μB and 10.97628 μ B.
关键词： DFT,Hf and Ta doping,spintronics,Half-metallic ferromagnetism,NiO
更新于2025-09-09 09:28:46
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doping
摘要： Results obtained on the visible light mediated photocatalytic properties of Al2O3 nanoparticles doped with Zn2+ ions synthesized by precipitation method is given in this paper. XRD, SEM, TEM, XPS, FT-IR and PL studies were performed to bring out the properties of the synthesized nanoparticles. Peaks related to monoclinic Al2O3 (θ -phase) was observed from the XRD patterns of the undoped and doped samples. A decrement of band gap from 3.86 eV to 3.71 eV with Zn doping has been observed. Oxygen vacancy related peaks were observed in the PL spectra of the samples. Enhanced degradation efficiency through Zn-doping has been observed for the Al2O3 nanoparticles against methyl orange. The maximum degradation efficiency of 90.69% observed for the 4 wt% Zn-doped Al2O3 catalyst was well acknowledged from its maximum degradation rate constant of 0.0273 min?1. The more stable nature of the Zn-doped Al2O3 photocatalysts confirmed their use as efficient photocatalysts for practical applications.
关键词： Photoluminescence,Doping,Photocatalyst,Visible light
更新于2025-09-09 09:28:46