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hexagonal boron nitride nanosheets incorporated antireflective silica coating with enhanced laser-induced damage threshold

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High Power Laser Science and Engineering 2018年第2期6卷 92-97页

作者： Jing Wang Chunhong Li Wenjie Hu Wei Han Qihua Zhu Yao Xu Institute of Coal Chemistry Chinese Academy of SciencesTaiyuan 030001China Research Center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900China State Key Laboratory of Transient Optics and Photonics Xi'an Institute of Optics and Precision MechanicsChinese Academy ofSciencesXi'an 710119China University of Chinese Academy of Sciences Beijing 100049China

boron nitride(BN) nanosheets incorporated silica antireflective(AR) coating was successfully prepared on fused silica substrate to improve the antilaser-damage ability of transmissive optics used in high-power laser systems. The BN nanosheets were obtained by urea assisted solid exfoliation, and then incorporated into basic-catalyzed silica sols without any further treatment. The transmission electron microscope(TEM) images indicated that the BN nanosheets generally consisted of 2–10 layers. The antireflective BN/SiO_2 coating exhibited excellent transmittance as high as 99.89% at351 nm wavelength on fused silica substrate. The thermal conductivity 0.135 W · m^(-1)· K^(-1) of the BN/SiO_2 coating with 10% BN addition was about 23% higher than 0.11 W · m^(-1)· K^(-1) of the pure SiO_2 AR coating. The laser-induced damage threshold(LIDT) of that BN/SiO_2 coating is also 23.1% higher than that of pure SiO_2 AR coating. This research provides a potential application of BN/SiO_2 coatings in high-power laser systems.

关键词： hexagonal boron nitride laser-induced damage silica antireflective coating thermal conductivity

Abnormal anti-oxidation behavior of hexagonal boron nitride grown on copper

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Nano Research 2022年第8期15卷 7577-7583页

作者： Li Wang Jiajie Qi Shuai Zhang Mingchao Ding Wei Wei Jinhuan Wang Zhihong Zhang Ruixi Qiao Zhibin Zhang Zehui Li Kehai Liu Ying Fu Hao Hong Can Liu Muhong Wu Wenlong Wang Jun He Yi Cui Qunyang Li Xuedong Bai Kaihui Liu State Key Laboratory for Mesoscopic Physics Frontiers Science Center for Nano-optoelectronicsSchool of PhysicsPeking UniversityBeijing 100871China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Department of Engineering Mechanics State Key Laboratory of TribologyTsinghua UniversityBeijing 100084China Vacuum Interconnected Nanotech Workstation Suzhou Institute of Nano-Tech and Nano-BionicsChinese Academy of SciencesSuzhou 215123China School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China International Centre for Quantum Materials Collaborative Innovation Centre of Quantum MatterPeking UniversityBeijing 100871China Songshan Lake Materials Laboratory Institute of PhysicsChinese Academy of SciencesDongguan 523808China CAS Center for Excellence in Nanoscience CAS Key Laboratory of Nanosystem and Hierarchical FabricationNational Center for Nanoscience and TechnologyBeijing 100190China School of Physical Sciences University of Chinese Academy of SciencesBeijing 100049China

Atomic-layered hexagonal boron nitride(hBN)is expected to be the best two-dimensional(2D)anti-oxidation layer on metals for its incomparable impermeability,insulativity,and stability,as well as the progressive bottom-up growth techniques to ensure fast coating on metal surface in large area.However,its real anti-oxidation ability in practice is found to be unsatisfactory and nonuniform,and the main obstacle to achieving ideal anti-oxidation performance lies in unclear anti-oxidation behavior at special interface between 2D hBN and three-dimensional(3D)metals.Herein,system of monolayer hBN grown on copper(Cu)foils with various lattice orientations was grown to investigate the anti-oxidation behavior of different interlayer configurations.By using structural characterizations together with analysis of topography,we surprisingly found that stronger interlayer coupling led to worse anti-oxidation performance owing to fast diffusion of O2 through higher hBN corrugations generated at the commensurate hBN/Cu(111)configuration.In view of this,we developed the approach of cyclic reannealing that can effectively flatten corrugations and steps,and therefore improve the anti-oxidation performance to a great extent.This work provides a more indepth understanding of anti-oxidation behavior of 2D materials grown on 3D metals,and a practical method to pave the way for its large-scale applications in future.

关键词： hexagonal boron nitride anti-oxidation of metals nanoscale corrugation cyclic reannealing method

N-hydroxyphthalimide anchored on hexagonal boron nitride as a metal-free heterogeneous catalyst for deep oxidative desulfurization

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Petroleum Science 2022年第3期19卷 1382-1389页

作者： Lin-Jie Lu Pei-Wen Wu Jing He Ming-Qing Hua Yan-Hong Chao Ning Yang Lin-Lin Chen Wei Jiang Lei Fan Hong-Bing Ji Wen-Shuai Zhu School of Chemistry and Chemical Engineering Institute for Energy ResearchJiangsu UniversityZhenjiangJiangsu212013PR China School of Pharmacy Jiangsu UniversityZhenjiangJiangsu212013PR China Yangzhou University YangzhouJiangsu225002PR China Fine Chemical Industry Research Institute School of ChemistrySun Yat-sen UniversityGuangzhouGuangdong510275PR China

A metal-free N-hydroxyphthalimide/hexagonal boron nitride(NHPI/h-BN)catalytic system was developed for deep oxidative desulfurization(ODS)of fuel oils.Detailed experiments find that the heterogenization process of loading NHPI on h-BN not only benefits to the dispersion and utilization of NHPI,but also can significantly promote the catalytic performance.By employing NHPI/h-BN as the catalyst,azodiisobutyronitrile(AIBN)as the metal-free initiator,a 95%conversion of dibenzothiophene(DBT)can be acquired under the reaction conditions of 120°C and atmospheric pressure with molecular oxygen(O_(2))as oxidant.Moreover,the heterogenization is convenient for the regeneration of the catalyst with>94%DBT conversion after being recycled seven times.Characterizations illustrate that the promoted catalytic activity along with the regenerability originate from the interactions between NHPI and h-BN.The catalytic mechanism study shows that molecular oxygen is readily activated by the NHPI/h-BN to form a superoxide radical(O_(2)^(·-)),which oxidize DBT to DBTO2 for desulfurization.

关键词： N-hydroxyphthalimide hexagonal boron nitride Oxidative desulfurization Heterogeneous catalysis

Ultrafast battery heat dissipation enabled by highly ordered and interconnected hexagonal boron nitride thermal conductive composites

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Green Energy & Environment 2022年第6期7卷 1401-1410页

作者： Zhuoya Wang Kaihang Zhang Bing Zhang Zheming Tong Shulan Mao Hao Bai Yingying Lu State Key Laboratory of Chemical Engineering Institute of Pharmaceutical EngineeringCollege of Chemical and Biological EngineeringZhejiang UniversityHangzhou310027China Brook Byers Institute of Sustainable Systems and School of Civil and Environmental Engineering Georgia Institute of TechnologyAtlantaGA30332USA ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou311200China State Key Laboratory of Fluid Power and Mechatronic Systems College of Mechanical EngineeringZhejiang UniversityHangzhou310027China

Heat dissipation involved safety issues are crucial for industrial applications of the high-energy density battery and fast charging technology.While traditional air or liquid cooling methods suffering from space limitation and possible leakage of electricity during charge process,emerging phase change materials as solid cooling media are of growing interest.Among them,paraffin wax(PW)with large latent heat capacity and low cost is desirable for heat dissipation and thermal management which mainly hindered by their relatively low thermal conductivity and susceptibility to leakage.Here,highly ordered and interconnected hexagonal boron nitride(h-BN)networks were established via ice template method and introduced into PW to enhance the thermal conductivity.The composite with 20 wt%loading amount of h-BN can guarantee a highly ordered network and exhibited high thermal conductivity(1.86 W m^(-1) K^(-1))which was 4 times larger compared with that of random dispersed h-BN involved PW and nearly 8 times larger compared with that of bare PW.The optimal thermal conductive composites demonstrated ultrafast heat dissipation as well as leakage resistance for lithium-ion batteries(LIBs),heat generated by LIBs can be effectively transferred under the working state and the surface temperature kept 6.9℃ lower at most under 2–5℃ continuous charge-discharge process compared with that of bare one which illustrated great potential for industrial thermal management.

关键词： hexagonal boron nitride Paraffin wax Lithium-ion batteries Thermal conductive network Battery heat dissipation

Influence of metal support in-plane symmetry on the corrugation of hexagonal boron nitride and graphene monolayers

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Nano Research 2018年第9期11卷 4643-4653页

作者： Antonio d. Martinez-Galera Jose M. Gomez-Rodriguez Departamento de Fisica de la Matefia Condensada Universidad Autonoma de Madrid Madrid E-28049 Spain Condensed Matter Physics Center (IFIMAC) UniversidadAutdnoma de Madrid Madrid E-28049 Spain Instituto Nicolds Cabrera Universidad Autonoma de Madrid Madrid E-28049 Spain

Predicting the properties of two-dimensional （2D） materials as graphene and hexagonal boron nitride （h-BN） monolayers after their growth on any given substrate is a major challenge. While the influence of the electron configuration of the atoms of the underlying surface is well-understood, the effect of substrate geometry still remains unclear. The structural properties of h-BN monolayers grown on a rectangularly packed Rh（110） surface were characterized in situ by ultrahigh vacuum scanning tunneling microscopy and were compared to those that this material exhibits when grown on substrates showing different crystallographic orientations. Although the h-BN monolayer grown on Rh（110） was dominated by a unique quasiunidimensional moir6 pattern, suggesting considerable interface interaction, the moir6 corrugation was unexpectedly smaller than those reported for strongly interacting interfaces with hexagonal-terminated substrates, owing to differences in the possible binding landscapes at interfaces with differently oriented substrates. Moreover, a rule was derived for predicting how interface corrugation and the existence and extent of subregions within moir6 supercells containing favorable sites for orbital mixing between h-BN monolayers and their supports depend on substrate symmetry. These general symmetry considerations can be applied to numerous 2D materials, including graphene, thereby enabling the prediction of how substrate choice determines the properties of these materials. Furthermore, they could also provide new routes for tuning 2D material properties and for developing nanotemplates showing different geometries for Krowing adsorbate superlattices.

关键词： hexagonal boron nitride graphene two-dimensional materials scanning tunneling microscopy moire superstructures nanotemplates

Intrinsic excitonic emission and valley Zeeman splitting in epitaxial MS2(M=Mo and W)monolayers on hexagonal boron nitride

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Nano Research 2018年第12期11卷 6227-6236页

作者： Chunxiao Cong Chenji Zou Bingchen Cao Lishu Wu Jingzhi Shahg Haomin Wang Zhijun Qiu Laigui Hu Pengfei Tian Ran Liu Ting Yu State Key Laboratory of ASIC and System School of Information Science and TechnologyFudan UniversityShanghai 200433China Division of Physics and Applied Physics School of Physical and Mathematical SciencesNanyang Technological UniversitySingapore 637371Singapore State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information TechnologyChinese Academy of Sciences865Changning RoadShanghai200050China

Two-dimensional (2D) semiconductors, represented by 2D transition metal dichalcogenides (TMDs), exhibit rich valley physics due to strong spin-orbit/spin-valley coupling. The most common way to probe such 2D systems is to utilize optical methods, which can monitor light emissions from various excitonic states and further help in understanding the physics behind such phenomena. Therefore, 2D TMDs with good optical quality are in great demand. Here, we report a method to directly grow epitaxial WS2 and MoS2 monolayers on hexagonal boron nitride (hBN) flakes with a high yield and high optical quality; these monolayers show better intrinsic light emission features than exfoliated monolayers from natural crystals. For the first time, the valley Zeeman splitting of WS2 and MoS2 monolayers on hBN has been visualized and systematically investigated. This study paves a new way to produce high optical quality WS2 and MoS2 monolayers and to exploit their intrinsic properties in a multitude of applications.

关键词： transition metal dichalcogenides intrinsic excitonic emission valley Zeeman splitting hexagonal boron nitride chemical vapor deposition

Remote heteroepitaxy of transition metal dichalcogenides through monolayer hexagonal boron nitride

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Nano Research 2024年第4期17卷 3224-3231页

作者： Jidong Huang Jingren Chen Junhua Meng Siyu Zhang Ji Jiang Jingzhen Li Libin Zeng Zhigang Yin Jinliang Wu Xingwang Zhang Key Lab of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Faculty of Science Beijing University of TechnologyBeijing 100124China

As a very promising epitaxy technology,the remote epitaxy has attracted extensive attention in recent years,in which graphene is the most used interlayer material.As an isomorphic of graphene,two-dimensional(2D)hexagonal boron nitride(h-BN),is another promising interlayer for the remote epitaxy.However,there is a current debate on the feasibility of using h-BN as interlayer in the remote epitaxy.Herein,we demonstrate that the potential field of sapphire can completely penetrate monolayer h-BN,and hence the remote epitaxy of ZrS_(2) layers can be realized on sapphire substrates through monolayer h-BN.The field of sapphire can only partially penetrate the bilayer h-BN and result in the mixing of remote epitaxy and van der Waals(vdWs)epitaxy.Due to the weak interfacial scattering and high crystalline quality of ZrS_(2) epilayer,the ZrS_(2) photodetector with monolayer h-BN shows the best performance,with an on/off ratio of more than 2×10^(5) and a responsivity up to 379 mA·W^(-1).This work provides an efficient approach to prepare single-crystal transition metal dichalcogenides and their heterojunctions with h-BN,which have great potential in developing large-area 2D electronic devices.

关键词： remote epitaxy hexagonal boron nitride transition metal dichalcogenides chemical vapor deposition photodetectors

Direct growth of hexagonal boron nitride films on dielectric sapphire substrates by pulsed laser deposition for optoelectronic applications

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Fundamental Research 2021年第6期1卷 677-683页

作者： Gaokai Wang Jingren Chen Junhua Meng Zhigang Yin Ji Jiang Yan Tian Jingzhen Li Jinliang Wu Peng Jin Xingwang Zhang Key Lab of Semiconductor Materials Science Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Faculty of Science Beijing University of TechnologyBeijing 100124China

Recently,hexagonal boron nitride(h-BN),an ultra-wide bandgap semiconductor,has attracted considerable atten-tion owing to its excellent properties.In thin films grown on metal catalysts,contamination and damage induced by a transfer process cannot be avoided.Therefore,synthesizing h-BN films on non-catalytic dielectric substrates is desirable for electronic applications.In this study,we demonstrate the direct growth of high-quality h-BN films with a controllable thickness on sapphire substrates by using the pulsed laser deposition(PLD)technique.The effects of the deposition conditions and laser parameters on the growth of the h-BN films are systematically investigated by evaluating their characteristic Raman peaks.Among the various growth parameters studied,the substrate temperature has the greatest influence on the crystalline quality of the h-BN films,and the optimal pres-sure varies depending on the target-substrate distance.The h-BN film grown under optimal conditions exhibits a narrow Raman line width of∼30 cm^(−1),indicating a high crystalline quality.The photodetectors fabricated from the PLD-grown h-BN films exhibit superior deep-ultraviolet detection performance with a large on/offratio of>104,high photoresponsivity,and a sharp cut-offwavelength of 220 nm.This study presents the possibility of producing high-quality h-BN films by applying PLD on dielectric substrates for optoelectronic applications.

关键词： hexagonal boron nitride Pulsed laser deposition Raman spectroscopy Photodetectors

Understanding the Thermal Impedance of Silicone Rubber/hexagonal boron nitride Composites as Thermal Interface Materials

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Chinese Journal of Polymer Science 2024年第3期42卷 352-363,I0008页

作者： Yuan Ji Shi-Da Han Hong Wu Shao-Yun Guo Feng-Shun Zhang Jian-Hui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of Plastic/Rubber Complex Processing TechnologyPolymer Research InstituteSichuan UniversityChengdu 610065China Institute of Chemical Materials China Academy of Engineering PhysicsMianyang 621900China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Silicone rubber(SR) composites are most widely used as thermal interface materials(TIMs) for electronics heat dissipation. Thermal impedance as the main bottleneck limiting the performance of TIMs is usually neglected. Herein, the thermal impedance of SR composites loaded with different levels of hexagonal boron nitride(h-BN) as TIMs was elaborated for the first time by the ASTM D 5470 standard test and finite element analysis. It was found that elastic modulus and surface roughness of SR composites increased with the increase of h-BN content, indicating that the conformity was reduced. When the assembly pressure was 0.69 MPa, there existed an optimal h-BN content at which the contact resistance was minimum(0.39 K·cm^(2)·W^(-1)). Although the decreased bond line thickness(BLT) by increasing the assembly pressure was beneficial to reduce the thermal impedance, the proper assembly pressure should be selected to prevent the warpage of the contact surfaces and the increase in contact resistance, according to the compression properties of the SR composites. This study provides valuable insights into fabrication of high-performance TIMs for modern electronic device applications.

关键词： Thermal interface materials hexagonal boron nitride Thermal impedance Surfaces