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Naibo Lin Fan Hu Yilin Sun Chenxu Wu Hongyao Xu Xiang Yang Liu 《Advanced functional materials》2014,24(33):5284-5290
The fabrication of bio‐hybrid functional films is demonstrated by applying a materials assembly technique. Based on the hierarchical structures of silk fibroin materials, functional molecular/materials, i.e., quantum dots (QDs), can be fixed to amino acid groups in silk fibroin films. It follows that white‐light‐emitting QD silk hybrid films are obtained by hydrogen bond molecular recognition to the –COO– groups functionalized to blue luminescent ZnSe (5.2 nm) and yellow luminescent CdTe (4.1 nm) QDs in a molar ratio of 30:1 of ZnSe to CdTe QDs. Simultaneously, a systematic blue shift in the emission peak is observed from the QD solution to QDs silk fibroin films. The significant blue shift hints the appearance of the strong interaction between QDs and silk fibroins, which causes strong white‐light‐emitting uniform silk films. The molecular recognized interactions are confirmed by high resolution transmission electron microscopy, field scanning electron microscope, and attenuated total internal reflectance Fourier transform infrared spectroscopy. The QD silk films show unique advantages, including simple preparation, tunable white‐light emission, easy manipulation, and low fabrication costs, which make it a promising candidate for multicomponent optodevices. 相似文献
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Niu Zhichuan Han Qin Ni Haiqiao Yang Xiaohong Xu Yingqiang Du Yun Zhang Shiyong Peng Hongling Zhao Huan Wu Donghai Li Sh 《半导体学报》2005,26(9):1860-1864
Material growth and device fabrication of the first 1.3μm quantum well (QW) edge emitting laser diodes in China are reported.Through the optimization of the molecular beam epitaxy (MBE) growth conditions and the tuning of the indium and nitrogen composition of the GaInNAs QWs,the emission wavelengths of the QWs can be tuned to 1.3μm.Ridge geometry waveguide laser diodes are fabricated.The lasing wavelength is 1.3μm under continuous current injection at room temperature with threshold current of 1kA/cm2 for the laser diode structures with the cleaved facet mirrors.The output light power over 30mW is obtained. 相似文献
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半导体材料研究的新进展 总被引：7，自引：0，他引：7
首先对作为现代信息社会的核心和基础的半导体材料在国民经济建设、社会可持续发展以及国家安全中的战略地位和作用进行了分析,进而介绍几种重要半导体材料如,硅材料、GaAs和InP单晶材料、半导体超晶格和量子阱材料、一维量子线、零维量子点半导体微结构材料、宽带隙半导体材料、光学微腔和光子晶体材料、量子比特构造和量子计算机用材料等目前达到的水平和器件应用概况及其发展趋势作了概述.最后,提出了发展我国半导体材料的建议.本文未涉及II-VI族宽禁带与II-VI族窄禁带红外半导体材料、高效太阳电池材料Cu(In,Ga)Se.CuIn(Se,S)等以及发展迅速的有机半导体材料等. 相似文献
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Martin Esmann Stephen C. Wein Carlos Antón-Solanas 《Advanced functional materials》2024,34(30):2315936
In this review, the current landscape of emergent quantum materials for quantum photonic applications is described. The review focuses on three specific solid-state platforms: single emitters in monolayers of transition metal dichalcogenides (TMDs), defects in hexagonal boron nitride (hBN), and colloidal quantum dots in perovskites (PQDs). These platforms share a unique technological accessibility, enabling the rapid implementation of testbed quantum applications, all while being on the verge of becoming technologically mature enough for a first generation of real-world quantum applications. The review begins with a comprehensive overview of the current state-of-the-art for relevant single-photon sources in the solid-state, introducing the most important performance criteria and experimental characterization techniques along the way. Progress for each of the three novel materials is then benchmarked against more established (yet complex) platforms, highlighting performance, material-specific advantages, and giving an outlook on quantum applications. This review will thus provide the reader with a snapshot on latest developments in the fast-paced field of emergent single-photon sources in the solid-state, including all the required concepts and experiments relevant to this technology. 相似文献
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Stefano Cecchi Daniele Dragoni Dominik Kriegner Elisa Tisbi Eugenio Zallo Fabrizio Arciprete Vclav Holý Marco Bernasconi Raffaella Calarco 《Advanced functional materials》2019,29(2)
In recent years strain engineering is proposed in chalcogenide superlattices (SLs) to shape in particular the switching functionality for phase change memory applications. This is possible in Sb2Te3/GeTe heterostructures leveraging on the peculiar behavior of Sb2Te3, in between covalently bonded and weakly bonded materials. In the present study, the structural and thermoelectric (TE) properties of epitaxial Sb2+xTe3 films are shown, as they represent an intriguing option to expand the horizon of strain engineering in such SLs. Samples with composition between Sb2Te3 and Sb4Te3 are prepared by molecular beam epitaxy. A combination of X‐ray diffraction and Raman spectroscopy, together with dedicated simulations, allows unveiling the structural characteristics of the alloys. A consistent evaluation of the structural disorder characterizing the material is drawn as well as the presence of both Sb2 and Sb4 slabs is detected. A strong link exists among structural and TE properties, the latter having implications also in phase change SLs. A further improvement of the TE performances may be achieved by accurately engineering the intrinsic disorder. The possibility to tune the strain in designed Sb2+xTe3/GeTe SLs by controlling at the nanoscale the 2D character of the Sb2+xTe3 alloys is envisioned. 相似文献
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Kum Hee Lee Lee Kyung Kang Jin Yong Lee Sunwoo Kang Soon Ok Jeon Kyoung Soo Yook Jun Yeob Lee Seung Soo Yoon 《Advanced functional materials》2010,20(8):1345-1358
Blue fluorescent materials based on silicone end‐capped 2‐diphenylaminofluorene derivatives are synthesized and characterized. These materials are doped into a 2‐methyl‐9,10‐di‐[2‐naphthyl]anthracene host as blue dopant materials in the emitting layer of organic light‐emitting diode devices bearing a structure of ITO/DNTPD (60 nm)/NPB (30 nm)/emitting layer (30 nm)/Alq3 (20 nm)/LiF (1.0 nm)/Al (200 nm). All devices exhibit highly efficient blue electroluminescence with high external quantum efficiencies (3.47%–7.34% at 20 mA cm?2). The best luminous efficiency of 11.2 cd A?1 and highest quantum efficiency of 7.34% at 20 mA cm?2 are obtained in a device with CIE coordinates (0.15, 0.25). A deep‐blue OLED with CIE coordinates (0.15, 0.14) exhibits a luminous efficiency of 3.70 cd A?1 and quantum efficiency of 3.47% at 20 mA cm?2. 相似文献
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本课程改革从新工科的视角进行研究,提出基于OBE理念实现从教师中心向学生中心转变,通过信息化教学手段辅助教学的教学模式和对分课堂的教学方法,实现学生求知欲、学习兴趣的提高,在教学内容上跟踪企业和科研发展,使学生所学知识与技能满足用人单位需求标准,采用多元化评价方法,分析评价反馈结果,推动课程教学质量的可持续性改进及提高。 相似文献
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Quantum cascade lasers (QCLs) represent the most fascinating achievement of quantum engineering, showing how artificial materials can be generated through quantum design, with tailor-made properties. Their inherent quantum nature deeply affects their core physical parameters. QCLs indeed display intrinsic linewidths approaching the quantum limit, and show spontaneous phase-locking of their emitted modes via intracavity four-wave-mixing, meaning that they can naturally operate as miniaturized metrological frequency rulers, also in frontier frequency domains, as the far-infrared, yet unexplored in quantum science. Here, the authors discuss the fundamental quantum properties of QCLs operating at terahertz frequencies and their key technological performances, highlighting future perspectives of this frontier research field in disruptive areas of quantum technologies such as quantum sensing, quantum metrology, quantum imaging, and photonic-based quantum computation. 相似文献
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用半导体激光(3.97 mW/mm2)和相干光及非相干光转换器(专利:CN2555523Y)将半导体激光转换为同功率、同波长和同光斑大小的非相干红光辐照小麦种子.通过分析幼苗期叶片DNA及生理变化,考察低剂量激光防护紫外线-B(UV-B)辐射损伤小麦幼苗的光效应.半导体激光预处理使10.08 kJ/m2UV-B辐射损伤小麦幼苗超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性,紫外吸收物含量、可溶性蛋白质含量、叶绿素a和叶绿素b含量及根长显著增加,丙二醛(MDA)含量显著降低.而非相干红光则不能.用酶联免疫(ELISA)方法检测小麦叶片DNA受UV-B辐射损伤产生的环丁烷嘧啶二聚体(CPD)含量,发现半导体激光能显著降低UV-B辐射损伤小麦细胞DNA中环丁烷嘧啶二聚体的含量,而非相干红光却不能使其降低.说明半导体激光防护UV-B辐射损伤小麦幼苗中光效应不起作用. 相似文献
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Materials with hierarchical porosity and structures have been heavily involved in newly developed energy storage and conversion systems. Because of meticulous design and ingenious hierarchical structuration of porosities through the mimicking of natural systems, hierarchically structured porous materials can provide large surface areas for reaction, interfacial transport, or dispersion of active sites at different length scales of pores and shorten diffusion paths or reduce diffusion effect. By the incorporation of macroporosity in materials, light harvesting can be enhanced, showing the importance of macrochannels in light related systems such as photocatalysis and photovoltaics. A state‐of‐the‐art review of the applications of hierarchically structured porous materials in energy conversion and storage is presented. Their involvement in energy conversion such as in photosynthesis, photocatalytic H2 production, photocatalysis, or in dye sensitized solar cells (DSSCs) and fuel cells (FCs) is discussed. Energy storage technologies such as Li‐ions batteries, supercapacitors, hydrogen storage, and solar thermal storage developed based on hierarchically porous materials are then discussed. The links between the hierarchically porous structures and their performances in energy conversion and storage presented can promote the design of the novel structures with advanced properties. 相似文献
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采用分子束外延技术,在GaAs衬底上生长GaAs,AlAs和AlGaAs时,实现RHEED图像和RHEED强度振荡的实时监测已被证明是一种有效工具。通过RHEED可讨论GaAs表面结构和生长机制,并可以估算衬底温度,更重要的是能计算出材料的生长速率。RHEED强度振荡周期决定生长速率,每一个周期对应一个单层。实验测量GaAs的生长周期为0.82s,每秒沉积1.22单分子层,AlAs的生长周期为2.35s,每秒沉积0.43单分子层。 相似文献
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摘 要：“电工学”是高等院校非电类专业的一门重要的专业基础课程。多年来,在传统课堂教学过程中存在着课时缩减、授课班级多、师生互动受限等问题。教学改革的目标不应是给学生灌输更多的知识,而是更多地关注学生的好奇心、想象力,从而激发他们自主学习的热情。 相似文献
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对激光三角法在生物医学工程中的应用进行了讨论、分类和总结,对激光三角法在生物医学领域中的更进一步应用具有实际指导意义. 相似文献
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Huikai Zhong Jun Xia Fengchao Wang Hongsheng Chen Hengan Wu Shisheng Lin 《Advanced functional materials》2017,27(5)
Recently, liquid flow over monolayer graphene has been experimentally demonstrated to generate an induced voltage in the flow direction, and various physical mechanisms have been proposed to explain the electricity‐generating process between liquid and graphene. However, there are significant discrepancies in the reported results with non‐ionic liquid: the observed voltage responses with deionized (DI) water vary from lab to lab under presumably similar flowing conditions. Here, a graphene‐piezoelectric material heterostructure is proposed for harvesting energy from water flow; it is shown that the introduction of a piezoelectric template beneath graphene results in an obvious voltage output up to 0.1 V even with DI water. This potential arises from a continuous charging–discharging process in graphene, which is suggested to be a result of a relatively retarded screening effect of the water for the generated piezoelectric charges than that of the graphene layer, as revealed by first‐principles calculations. This work considers a dynamic charge interaction among water, graphene, and the substrate, highlighting the crucial role of the underlying substrate in the electricity‐generating process, which will greatly enhance understanding of the flow‐induced voltage and push the graphene‐water nanogenerator close to practical applications. 相似文献
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Mohammed Sayyad Ying Qin Jan Kopaczek Adway Gupta Naim Patoary Shantanu Sinha Emmie Benard Austin Davis Kentaro Yumigeta Cheng-Lun Wu Han Li Shize Yang Ivan Sanchez Esqueda Arunima Singh Sefaattin Tongay 《Advanced functional materials》2023,33(42):2303526
2D Janus transition metal dichalcogenides (TMDs) have attracted attention due to their emergent properties arising from broken mirror symmetry and self-driven polarization fields. While it has been proposed that their vdW superlattices hold the key to achieving superior properties in piezoelectricity and photovoltaic, available synthesis has ultimately limited their realization. Here, the first packed vdW nanoscrolls made from Janus TMDs through a simple one-drop solution technique are reported. The results, including ab initio simulations, show that the Bohr radius difference between the top sulfur and the bottom selenium atoms within Janus (M = Mo, W) results in a permanent compressive surface strain that acts as a nanoscroll formation catalyst after small liquid interaction. Unlike classical 2D layers, the surface strain in Janus TMDs can be engineered from compressive to tensile by placing larger Bohr radius atoms on top (to yield inverted C scrolls. Detailed microscopy studies offer the first insights into their morphology and readily formed Moiré lattices. In contrast, spectroscopy and FETs studies establish their excitonic and device properties and highlight significant differences compared to 2D flat Janus TMDs. These results introduce the first polar Janus TMD nanoscrolls and introduce inherent strain-driven scrolling dynamics as a catalyst to create superlattices. 相似文献
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生物医用钛合金的激光表面改性 总被引：1，自引：0，他引：1
生物医用钛及其合金是外科植入首选的替代材料,激光表面改性是改善钛合金表面磨损和腐蚀性能的有效方法。采用高功率连续波Nd:YAG激光在Ti6Al4V合金表面进行激光气体氮化改性,获得了均匀致密、无孔洞裂纹等缺陷的氮化物改性层,合金表面对人体有害元素Al、V含量明显降低。利用扫描电子显微镜(SEM)、显微硬度计、振动摩擦磨损实验机及恒电位仪对Ti6Al4V合金气体氮化改性层的组织、磨损及在模拟人体体液中的电化学腐蚀性能进行研究。实验结果表明,激光气体氮化改善了Ti6Al4V合金作为生物医学材料使用的表面性能,其抗磨损及腐蚀性能显著提高。 相似文献