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thermal annealing induced photocarrier radiometry enhancement for ion implanted silicon wafers

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Chinese Physics B 2010年第9期19卷 519-524页

作者：刘显明李斌成黄秋萍 Institute of Optics and Electronics Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences

An experimental study on the photocarrier radiometry signals of As^＋ ion implanted silicon wafers before and after rapid thermal annealing is performed. The dependences of photocarrier radiometry amplitude on ion implantation dose （1×10^11-1×10^16/cm^2）, implantation energy （20-140 keV） and subsequent isochronical annealing temperature （500- 1100℃ are investigated. The results show that photocarrier radiometry signals are greatly enhanced for implanted samples annealed at high temperature, especially for those with a high implantation dose. The reduced surface recombination rate resulting from a high built-in electric field generated by annealing-activated impurities in the pn junction is believed to be responsible for the photocarrier radiometry signal enhancement. Photocarrier radiometry is contactless and can therefore be used as an effective in-line tool for the thermal annealing process monitoring of the ion-implanted wafers in semiconductor industries.

关键词： photocarrier radiometry ion implantation thermal annealing silicon

thermal annealing synthesis of double-shell truncated octahedral Pt-Ni alloys for oxygen reduction reaction of polymer electrolyte membrane fuel cells

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Frontiers in Energy 2020年第4期14卷 767-777页

作者： Xiashuang LUO Yangge GUO Hongru ZHOU Huan REN Shuiyun SHEN Guanghua WEI Junliang ZHANG Institute of Fuel Cells School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China Shanghai Hydrogen Propulsion Technology Co. LtdShanghai 201804China SJTU-Paris Tech Elite Institute of Technology Shanghai Jiao Tong UniversityShanghai 200240China Institute of Fuel Cells School of Mechanical EngineeringMOE Key Laboratory for Power Machinery and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Shape-controlled Pt-Ni alloys usually offer an exceptional electrocatalytic activity toward the oxygen reduction reaction(ORR)of polymer electrolyte membrane fuel ceils(PEMFCs),whose tricks lie in welldesigned structures and surface morphologies.In this paper,a novel synthesis of truncated octahedral PtNi_(3.5) alloy catalysts that consist of homogeneous Pt-Ni alloy cores enclosed by NiO-Pt double shells through thermally annealing defective heterogeneous PtNi35 alloys is reported.By tracking the evolution of both compositions and morphologies,the outward segregation of both PtOv and NiO are first observed in Pt-Ni alloys.It is speculated that the diffusion of low-coordination atoms results in the formation of an energetically favorable truncated octahedron while the outward segregation of oxides leads to the formation of NiO-Pt double shells.It is very attractive that after gently removing the NiO outer shell,the dealloyed truncated octahedral core-shell structure demonstrates a greatly enhanced ORR activity.The asobtained truncated octahedral Pt_(2.1)Ni core-shell alloy presents a 3.4-folds mass-specific activity of that for unannealed sample,and its activity preserves 45.4%after 30000 potential cycles of accelerated degradation test(ADT).The peak power density of the dealloyed truncated octahedral Pt2jNi core-shell alloy catalyst based membrane electrolyte assembly(MEA)reaches 679.8 mW/cm^(2),increased by 138.4 mW/cm^(2) relative to that based on commercial Pt/C.

关键词： dealloyed Pt-Ni alloys truncated octahedron double-shell thermal annealing oxygen reduction reaction(ORR)

thermal annealing behaviour of Al/Ni/Au multilayer on n-GaN Schottky contacts

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Chinese Physics B 2009年第4期18卷 1618-1621页

作者：刘芳王涛沈波黄森林芳马楠许福军王鹏姚建铨 College of Precision Instrument and Opto-Electronics Engineering Institute of Laser and Optoelectronics Tianjin University Key Lab of Optoelectric Information Science and Technology of Ministry of Education Tianjin University State Key Laboratory of Artificial Microstructure and Mesoscopic Physics School of Physics Peking University

Recently GaN-based high electron mobility transistors （HEMTs） have revealed the superior properties of a high breakdown field and high electron saturation velocity. Reduction of the gate leakage current is one of the key issues to be solved for their further improvement. This paper reports that an Al layer as thin as 3 nm was inserted between the conventional Ni/Au Schottky contact and n-GaN epilayers, and the Schottky behaviour of Al/Ni/Au contact was investigated under various annealing conditions by current-voltage （I-V） measurements. A non-linear fitting method was used to extract the contact parameters from the I-V characteristic curves. Experimental results indicate that reduction of the gate leakage current by as much as four orders of magnitude was successfully recorded by thermal annealing. And high quality Schottky contact with a barrier height of 0.875 eV and the lowest reverse-bias leakage current, respectively, can be obtained under 12 min annealing at 450 ℃ in N2 ambience.

关键词： Schottky contact barrier height ideality factor thermal annealing

Design and fabrication of GeAsSeS chalcogenide waveguides with thermal annealing

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Chinese Physics B 2021年第3期30卷 320-325页

作者：张李萌陈锦波顾杰荣高一骁沈祥陈益敏徐铁峰 Laboratory of Infrared Materials and Devices&Key Laboratory of Photoelectric Detection Materials and Devices of Zhejiang Province Research Institute of Advanced TechnologyNingbo UniversityNingbo 315211China Ningbo Institute of Oceanography Ningbo 315832China Department of Microelectronic Science and Engineering School of Physical Science and TechnologyNingbo UniversityNingbo 315211China

We reported a chalcogenide glass-based rib waveguide fabricated using photolithography and dry etching method. A commercial software(COMSOL Multiphysics) was used to optimize the waveguide structure and the distribution of the fundamental modes in the waveguide based on the complete vector finite component. We further employed thermal annealing to optimize the surface and sidewalls of the rib waveguides. It was found that the optimal annealing temperature for Ge As Se S films is 220℃, and the roughness of the films could be significantly reduced by annealing. The zero-dispersion wavelength(ZDW) could be shifted to a short wavelength around ~2.1 μm via waveguide structural optimization, which promotes supercontinuum generation with a short wavelength pump laser source. The insertion loss of the waveguides with cross-sectional areas of 4.0 μm×3.5 μm and 6.0 μm×3.5 μm was measured using lens fiber and the cut-back method. The propagation loss of the 220℃ annealed waveguides could be as low as 1.9 d B/cm at 1550 nm.

关键词： chalcogenide film dispersion engineering optical waveguide thermal annealing

Effect of thermal annealing on Mid-Infrared Transmission in Semiconductor Alloy-Core Glass-Cladded Fibers

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Advanced Fiber Materials 2020年第3期2卷 178-184页

作者： Mustafa Ordu Jicheng Guo Ahmet E.Akosman Shyamsunder Erramilli Siddharth Ramachandran Soumendra N.Basu Department of Mechanical Engineering Boston UniversityBostonMA 02215USA UNAM‑National Nanotechnology Research Center and Institute of Materials Science and Nanotechnology Bilkent UniversityAnkara 06800Turkey Division of Materials Science and Engineering Boston UniversityBrooklineMA 02446USA Argonne National Laboratory LemontIL 60439USA School of Engineering Roger Williams UniversityBristolRI 02809USA Department of Physics Boston UniversityBostonMA 02215USA Photonics Center Boston UniversityBostonMA 02215USA Department of Electrical and Computer Engineering Boston UniversityBostonMA 02215USA

We report a study investigating the effects of thermal annealing on the optical properties of Si-Ge alloy-core silica-cladded fibers.Low temperature fiber draw was performed with a laboratory-made draw tower at 1760°C that minimizes impurity diffusion from cladding to the core.As a post-drawing process,Si-Ge core fibers were annealed in a box furnace to alter the core structure.Microstructural and optical properties of fibers were investigated,and transmission losses were measured as 28 dB/cm at 6.1μm.Numerical studies were performed to analyze the experimental results and to find the optimum structure for low loss semiconductor-core glass-cladded fibers.

关键词： Semiconductor-core fibers Mid-IR fibers thermal annealing Si-Ge alloys

Controlled Fabrication of Uniform Digital Nanorods from Precise Sequence-Defined Amphiphilic Polymers in Aqueous Media

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Chinese Journal of Polymer Science 2023年第5期41卷 768-777,I0010页

作者： Qiang-Qiang Shi Xin Zhou Jie Xu Ning Wang Jia-Lin Zhang Xiang-Long Hu Shi-Yong Liu CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China School of Biomedical Engineering and Suzhou Institute for Advanced Research University of Science and Technology of ChinaSuzhou 215123China

Compared with spherical micelles,rod/worm-like micelles not only have extended blood circulation duration,but also exhibit favorable cellular uptake behavior,which is promising for next-generation nanomedicine and biomaterials.However,the controllable fabrication of narrowly dispersed nanorods in aqueous media is still challenging.Herein,the methodology of thermal annealing was developed for the fabrication of helical nanorods as well as a series of nanorods with different lengths.The thermal annealing process generally consisted of adding a percentage of organic solvent(10%(V/V)or 20%(V/V))to the digital micellar aqueous dispersion,followed by heating at 90℃for 1 h,then cooling naturally to room temperature,and dialyzing against water to remove the organic solvent.Right-handed helical nanorods were afforded by the treatment of 45 nm digital micelles in the presence of 10%(V/V)dioxane,while left-handed helical nanorods were obtained in the presence of 20%(V/V)dioxane.Meanwhile,the controlled growth of rod-like digital micelles was achieved after thermal annealing in the presence of different types of organic solvents,and the length of the annealed nanorods was correlated with the types of organic solvent.Furthermore,no matter the size of initial digital micelles,they all exhibited similar trend of rod growth in the presence of a certain amount of organic solvent,allowing for controllable formulation of narrowly dispersed nanorods.In addition,supramolecular self-assembly by amphiphilic dendritic oligourethane readily fabricated diverse uniform nanorods in aqueous media.Overall,this work provided an attractive methodology to fabricate uniform digital nanorods.

关键词： Sequence-defined amphiphilic polymers Digital nanorods thermal annealing Dendritic oligourethane Self-assembly

annealing optimization of hydrogenated amorphous silicon suboxide film for solar cell application

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Journal of Semiconductors 2011年第5期32卷 7-9页

作者：贾广智刘洪刚常虎东 Institute of Microelectronics Chinese Academy of Sciences

We investigate a passivation scheme using hydrogenated amorphous silicon suboxide （a-SiOx ：H） film for industrial solar cell application. The a-SiOx ：H films were deposited using plasma-enhanced chemical vapor deposition （PECVD） by decomposing nitrous oxide, helium and silane at a substrate temperature of around 250 ℃. An extensive study has been carried out on the effect of thermal annealing on carrier lifetime and surface recombination velocity, which affect the final output of the solar cell. Minority carrier lifetimes for the deposited a-SiOx ：H films without and with the thermal annealing on 4 Ω-cm p-type float-zone silicon wafers are 270 μs and 670μs, respectively, correlating to surface recombination velocities of 70 cm/s and 30 cm/s. Optical analysis has revealed a distinct decrease of blue light absorption in the a-SiOx ：H films compared to the commonly used intrinsic amorphous silicon passivation used in solar cells. This paper also reports that the low cost and high quality passivation fabrication sequences employed in this study are suitable for industrial processes.

关键词： a-SiOx H thermal annealing PECVD

Influence of thermal treatment on electronic properties of inkjet-printed zinc oxide semiconductor

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International Journal of Smart and Nano Materials 2022年第2期13卷 330-345页

作者： Van-Thai Tran Yuefan Wei Hejun Du Singapore Centre for 3D Printing Nanyang Technological UniversitySingapore Advanced Remanufacturing and Technology Centre Singapore School of Mechanical and Aerospace Engineering Nanyang Technological UniversitySingapore

Additive manufacturing of electronic devices using inkjet printing provides a potential alternative approach in substitution for con-ventional electronic fabrication processes.However,the complex nature of inkjet printing involves the liquid deposition and film formation from the vaporization of solvent,which makes it different from film created by conventional deposition methods.Inkjet print-ing of zinc oxide(ZnO),which is a widely utilized semiconductor,produces polycrystalline film composed of nano-size grains,which could significantly influence the properties of printed film.In this study,low-temperature annealing was employed to treat inkjetprinted ZnO for UV photodetection application,and its influence on electrical properties was studied.Band bending was character-ized using the Mott-Schottky plot which examines the charge dis-tribution of the films.It is found that the annealing of inkjet-printed polycrystalline ZnO film has improved its electrical properties,which could be attributed to the reduction of band bending due to the merging of grains.The treatment also helps to reduce impurities of the film,such as zinc hydroxide complexes,which is common for solution-derived films.Hence,the study could pay the way for the improvement of electrical properties of inkjet-printed functional materials.

关键词： Inkjet printing zinc oxide electrical properties band bending thermal annealing

Effects of annealing Temperature on the Properties of Copper Films Prepared by Magnetron Sputtering

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Journal of Wuhan University of Technology(Materials Science) 2015年第1期30卷 92-96页

作者：刘一鸣 ZHANG Jianjun ZHANG Wanggang 梁伟 YU Bin XUE Jinbo College of Materials Science and Engineering Taiyuan University of Technology Shanxi Institute of Analytical Science

Copper oxide thin films were prepared by a direct-current magnetron sputtering method followed by a thermal annealing treatment at 100-500 ℃. The obtained films were characterized by X-ray diffraction, UV-vis absorption spectroscopy, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. With the increase of the annealing temperature, it was found that the films transformed sequentially from amorphous to single-phase Cu （100℃）, mixed-phase of Cu and Cu2O （150 ℃）, single-phase Cu2O （200 ℃）, then to mixed-phase of Cu2O and CuO （300 ℃）, and finally to single-phase CuO （400 - 500 ℃）. Further analyses indicated that the Cu/Cu2O thin films and the Cu：O thin films presented no further oxidation even on the surface in air atmosphere. Additionally, the visible-light photocatalytic behavior of the copper oxide thin films on the degradation of methylene blue （MB） was also investigated, indicating that the films with pure Cu2O phase or Cu/Cu2O mixed phases have excellent photocatalytic efficiencies.

关键词： copper oxide thin films magnetron sputtering thermal annealing