NEW JOURNAL OF PHYSICS
·
2021
·Vol. 23
·期 3
·033019
·
IF 3.732
Bingsuo Zou,Lipeng Hou,Ye Tian,Junbo Han,Hui Peng,Xiongtao Yang,Lijie Shi
The magnetic excitons in diluted magnetic semiconductor (DMS) have varied formats due to the inhomogeneous phases out of doping concentration and/or structural relaxations or defects. Here the high quality cobalt-doped zinc blende ZnSe nanoribbons (NRs) were synthesized, showing bright and color-variable emissions from blue, yellow to a little mixed white colors. Their power and temperature dependent micro-photoluminescence (PL) spectra have been obtained in which two emission bands, one magnetic exciton band near the band-edge and a Co2+ high-level d–d transition emission band at 550 nm out of their ferromagnetic (FM) coupled aggregates in ZnSe lattice, both bands could also be reflected by a nonlinear optical absorption enhancement. The easy formed stacking fault defects in a chemical vapor deposition (CVD) grown ZnSe zincblende NR took part in the above optical processes out of magnetic polaronic excitons (PXs). The femtosecond (fs) laser pulse pumping on single ZnSe:Co NR produces obvious lasing behavior but with profile of a complicated magnetic exciton interactions with indication of a crossover from collective exciton magnetic polarons (EMP) to bound magnetic polaron (BMP) scattering in Co doped ZnSe NR. These findings indicate the complication of the magnetic coupling natures in varied DMS structures, whose optical properties have been found to be highly nonlinear, due to the involvement of the spin–spin, spin–exciton and spin–phonon interactions, verified by the theoretic calculation in Yang X-T et al (2019 Interstitial Zn-modulated ferromagnetism in Co-doped ZnSe Mater. Res. Express 6 106121).
研究领域:
材料科学
·
光学
·
半导体物理
·
纳米技术
·
磁学
✓ 已验证
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 8
·1062
·
IF 4.034
Yi Chu,Yingjie Xing,Hongqi Xu
SmB6nanowires, as a prototype of nanostructured topological Kondo insulator, have shown rich novel physical phenomena relating to their surface. Catalyst-assisted chemical vapor deposition (CVD) is a common approach to prepare SmB6nanowires and Ni is the most popular catalyst used to initiate the growth of SmB6nanowires. Here, we study the effect of growth mechanism on the surface of SmB6nanowires synthesized by CVD. Two types of SmB6nanowires are obtained when using Ni as the catalyst. In addition to pure SmB6nanowires without Ni impurity, a small amount of Ni is detected on the surface of some SmB6nanowires by element analysis with transmission electron microscopy. In order to eliminate the possible distribution of Ni on nanowire surface, we synthesize single crystalline SmB6nanowires by CVD without using catalyst. The difference between catalyst-assisted and catalyst-free growth mechanism is discussed.Keywords:nanowires;synthesis;CVD;topological insulators;growth mechanism
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Crystals
·
2022
·Vol. 12
·期 7
·985
·
IF 2.67
Yuhan Feng,Yumin Zhang,Jipeng Liu,Ye Zhang,Yongshuai Xie
Due to its high thermal and chemical stability, excellent dielectric properties, unique optical properties, corrosion resistance, and oxidation resistance, the two-dimensional hexagonal boron nitride (h-BN) is often used in a thermal conductor protective layer in deep ultraviolet light-emitting detector fields. However, due to the complicated growth conditions of h-BN, it is often necessary to prepare h-BN by the CVD method in a high vacuum environment, which is limited to a certain extent in terms of film size and production cost. In order to solve this problem, we proposed a method to prepare h-BN thin films by atmospheric CVD (APCVD). This method does not need a vacuum environment, which reduces energy consumption and cost, and makes the operation simpler and the experimental environment safer. The preparation of high-quality h-BN film was carried out using a Cu-Ni alloy as the growth substrate. The growth process of h-BN film was studied, and the influence of growth parameters on the structure of the h-BN film was explored. The morphological features and elemental composition pairs of the samples were characterized and analyzed, which confirmed that the high-quality h-BN film could be successfully grown on the Cu-Ni alloy substrate by APCVD. The UV detection device prepared by using the prepared h-BN film as the photoresponse material had good photoresponse characteristics and performance stability. It provides a new idea for the low-cost preparation of large-scale h-BN.Keywords:APCVD;h-BN;film;photoelectric devices
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2024
·Vol. 12
·期 32
·12571-12581
·
IF 5.7
Kaiyi Zhang,Fang Wang,Lei Zheng,Junqing Wei,Yongxu Hu,Yangyang Xie,Hongling Guo,Fengpu Zhang,Xin Lin,Zewen Li,Tianling Ren,Zhitang Song,Kailiang Zhang
2D Bi2O2Se is an intriguing building block for next-generation optoelectronic devices owing to its ultrahigh electron mobility and ultrabroadband photodetection capability. However, fully exploiting its advantages in advanced optoelectronic applications remains greatly challenging owing to the lack of in-depth understanding of the morphological evolution of Bi2O2Se crystals and efficient methods for enhancing their photoresponse. Herein, we developed a novel “cage-confinement” technique to achieve dimensionality-tunable growth of Bi2O2Se crystals in a space-confined CVD system. It can effectively control the key parameter of determining the dimensionality of crystals, referred to as the elastic strain energy of nucleation (ΔGs), by tuning the active area size of Bi2O3 seeds at a suitable flow rate of carrier gas. Furthermore, based on an optimized van der Waals transfer technique of crystals and electrodes, a sheet-shaped phototransistor of Bi2O2Se has a high responsivity (R) of ∼74 000 A W−1 and detectivity (D*) of ∼4.0 × 1011 Jones. Meanwhile, a wire-shaped device demonstrates an impressive R value of 300 000 A W−1, D* value of 3.9 × 1012 Jones and photoconductance gain (Gph) of 1.2 × 105. These results surpass most reported Bi2O2Se-based detectors and pave the way for the applications of 2D layered semiconductors in advanced optoelectronic devices and technologies.
研究领域:
材料科学
·
光电子学
✓ 已验证
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 10
·2190
·
IF 3.1
Xuemin Luo,Yanhui Jiao,Hang Li,Qi Liu,Jinfeng Liu,Mingwei Wang,Yong Liu
Transition metal dichalcogenides (TMDs), particularly monolayer TMDs with direct bandgap properties, are key to advancing optoelectronic device technology. WSe2stands out due to its adjustable carrier transport, making it a prime candidate for optoelectronic applications. This study explores monolayer WSe2synthesis via H2-assisted CVD, focusing on how carrier gas flow rate affects WSe2quality. A comprehensive characterization of monolayer WSe2was conducted using OM (optical microscope), Raman spectroscopy, PL spectroscopy, AFM, SEM, XPS, HRTEM, and XRD. It was found that H2incorporation and flow rate critically influence WSe2’s growth and structural integrity, with low flow rates favoring precursor concentration for product formation and high rates causing disintegration of existing structures. This research accentuates the significance of fine-tuning the carrier gas flow rate for optimizing monolayer WSe2synthesis, offering insights for fabricating monolayer TMDs like WS2, MoSe2, and MoS2, and facilitating their broader integration into optoelectronic devices.
研究领域:
材料科学
·
化学工程
·
光学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Communications
·
2024
·
IF 3.7
Jie You,Yang Wang,Hongwei Wang,Jian Yang,Quan Li,Jian Gu
In this paper, a new process for preparing porous SiC foam with three-dimensional network structure is presented. A certain thickness of SiC coating is deposited on the surface of ultra-light carbon skeleton by CVD process, so as to achieve effective control of its structure and mechanical properties. The effects of CVD deposition time on the density, porosity and skeleton thickness rates of SiC foams were explored. By increasing the CVD deposition time, the structure of SiC foams can be effectively regulated, and the mechanical properties of SiC foams can be significantly improved. The porosity of the prepared SiC foam can be adjusted in a wide range (26.9%∼94.68%). When the density of SiC foam increases from 0.67 g/cm 3 to 2.36 g/cm 3 , its bending strength increases from 27.4 MPa to 136.9 MPa, which is significantly improved. After high temperature oxidation treatment (800–1200 °C), the mechanical properties of SiC foam will be further improved. However, when the oxidation temperature reaches 1400 °C, its mechanical properties will be reduced. This research provides a new idea for the preparation of high-performance porous SiC ceramics, and lays a foundation for its structural design, manufacture and application.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2025
·Vol. 60
·期 6
·2804-2817
·
IF 3.9
Tang Kai,Chen Siyuan,Wang Xuchun,Zhang Xueru,Zhang Yong,Ke Xiang,Xu Xinru,Wu Tao,Wang Bingxin,Li Shasha
MoO 2 is a promising material for efficient and cost-effective electrocatalytic water splitting, particularly for the oxygen evolution reaction (OER) in alkaline media. Modifying the morphology, composition, or oxidation state of MoO 2 can enhance its active surface area and performance. In this study, Mo-coated carbon paper was used as a substrate to synthesize well-organized MoO 2 nanowires and nanosheets via a one-step CVD method without any catalyst. The nanosheets and nanowires grow perpendicularly to the substrate. MoO 2 nanowire arrays exhibit superior OER performance, characterized by a lower onset potential (1.54 V), a smaller Tafel slope, and enhanced durability compared to nanosheets. This improvement is likely attributed to the increased number of exposed active sites, reduced presence of oxidized Mo 4+ , and smaller crystalline size. Graphical abstract Here, well-organized MoO 2 nanowires and nanosheets have been fabricated on carbon paper using a one-step CVD method by reducing MoO 3 with Mo powder to investigate the intrinsic relationship between morphology, elemental composition and state, and their electrocatalytic properties. The obtained nanosheets presented as a flower-like structure, while nanowires formed into well-aligned arrays. MoO 2 nanowires contained higher amounts of Mo 4+ , were composed of smaller crystal grains, and possessed a lower onset potential for OER (oxygen evolution reaction) at about 1.54 V, a smaller Tafel slope at about 110 mV/dec, and better durability when compared to MoO 2 nanosheets.
研究领域:
材料科学
·
电催化
✓ 已验证
DOI
高影响因子
Crystals
·
2016
·Vol. 6
·期 11
·151
·
IF 2.075
Di Wu,Han Huang,Xupeng Zhu,Yanwei He,Qiliang Xie,Xiaoliu Chen,Xiaoming Zheng,Huigao Duan,Yongli Gao
Molybdenum disulfide (MoS2) has recently attracted considerable interests due to its unique properties and potential applications. Chemical vapor deposition (CVD) method is used widely to grow large-area and high-quality MoS2single crystals. Here, we report our investigation on thermal strain-fractured (SF) single crystalline MoS2, oxidation-fractured MoS2, and normal MoS2by atomic force microscopy (AFM), Raman and photoluminescence (PL) measurements. Several new Raman modes are observed for SF-MoS2. The band gap of SF-MoS2is enlarged by 150 meV and the PL intensity is reduced substantially. These results imply that a structural transformation occurs in SF-MoS2. Our findings here are useful for the design of MoS2-based nanocatalysts with relative high catalytic activity.Keywords:thermal strain-fractured MoS2;defect;Raman spectrum;photoluminescence spectrum;structural transformation
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
Physica Status Solidi-Rapid Research Letters
·
2016
·Vol. 10
·期 7
·549-553
·
IF 2.578
Song Hao,Bingchu Yang,Yongli Gao
We report a simple and effective way of fabricating molybdenum disulfide (MoS 2 ) nanoscrolls by self-rolling up fractured monolayer CVD-grown MoS 2 microflakes. Morphological results reveal that MoS 2 nanoscrolls are formed only at newly formed edges, owing to an orientation-specific fracture behavior. Using Raman spectroscopy, we show that the E 1 2g Raman peak (A 1g peak) for MoS 2 nanoscrolls significantly red-shifts (blue-shifts), indicating structural change. The proposed mechanism is that the newly formed edges induced by fracture behavior self-roll up to nanoscrolls to minimize the surface free energy, meanwhile, the serious lattice contradiction of upper sulfur plane controls the rolling directions. (© 2016 WILEY-VCH Verlag GmbH &Co. KGaA, Weinheim)
✓ 已验证
DOI
高影响因子
Nano Research
·
2016
·Vol. 10
·期 5
·1608-1617
·
IF 8.893
Zafar Amina,Nan Haiyan,Zafar Zainab,Wu Zhangting,Jiang Jie,You Yumeng,Ni Zhenhua
Optical emission efficiency of two-dimensional layered transition metal dichalcogenides (TMDs) is one of the most important parameters affecting their optoelectronic performance. The optimization of the growth parameters by chemical vapor deposition (CVD) to achieve optoelectronic-grade quality TMDs is, therefore, highly desirable. Here, we present a systematic photoluminescence (PL) spectroscopic approach to assess the intrinsic optical and crystalline quality of CVD grown MoS 2 (CVD MoS 2 ). We propose the use of the intensity ratio between the PL measured in air and vacuum as an effective way to monitor the intrinsic optical quality of CVD MoS 2 . Low-temperature PL measurements are also used to evaluate the structural defects in MoS 2 , via defect-associated bound exciton emission, which well correlates with the field-effect carrier mobility of MoS 2 grown at different temperatures. This work therefore provides a sensitive, noninvasive method to characterize the optical properties of TMDs, allowing the tuning of the growth parameters for the development of optoelectronic devices.
研究领域:
材料科学
·
光电子学
·
纳米技术
·
半导体物理
✓ 已验证
DOI
高影响因子
Coatings
·
2022
·Vol. 12
·期 3
·329
·
IF 3.236
Rong Tu,Chengyin Liu,Qingfang Xu,Kai Liu,Qizhong Li,Xian Zhang,Marina L. Kosinova,Takashi Goto,Song Zhang
SiC epitaxial wafers offer enormous potential for a wide range of telecom technologies due to their excellent properties. The experimental process was simulated by software, and the contour of gas flow velocity and raw material mass fraction inside the chamber were obtained. SiC films were epitaxially grown on 4H-SiC single crystalline substrates at different temperatures for one batch, using SiCl4, CH4, and H2as precursors. With increasing temperature, the crystal phase changed from 4H-SiC at 1773 K to a mixture of 4H- and 3C-SiC, and then a mixture of 3C-SiC and graphite at higher than 1923 K. The film was mainly (004)-oriented 4H-SiC and (111)-oriented 3C-SiC.Keywords:SiC film;high-frequency induction-heated halide CVD;crystalline phases distribution;microstructure;orientation
研究领域:
材料科学
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL COMMUNICATIONS
·
2025
·
IF 4.2
Shu Li,Chuanhe Ma,Fushuai Li,Jinchun Jiang,Hailong Wang
In this study, we successfully synthesized Cs3MnBr5 films via vapor deposition for the first time using CsBr and MnBr2 raw materials. The optimal deposition temperature is 900°C, achieving a maximum PLQY of 63.5%, an emission peak at 520 nm and a FWHM of 31.9 nm. Additionally, TG and DSC measurements indicate the films possess excellent thermal stability up to 600°C.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）