Nitrogen doping in chemical vapor deposition-derived ultrananocrystalline diamond(UNCD)films in-creases the electronic conductivity,yet its microstructural effects on electron transport are insufficiently understood.W...Nitrogen doping in chemical vapor deposition-derived ultrananocrystalline diamond(UNCD)films in-creases the electronic conductivity,yet its microstructural effects on electron transport are insufficiently understood.We investigated the formation of nitrogen-induced diaph-ite structures(hybrid diamond-graphite phases)and their role in changing the conductivity.Nitrogen doping in a hy-drogen-rich plasma environment promotes the emergence of unique sp^(3)-sp^(2)bonding interfaces,where diamond grains are covalently integrated with graphitic domains,facilitating a structure-driven electronic transition.High-resolution transmis-sion electron microscopy and selected area electron diffraction reveal five-fold,six-fold and twelve-fold symmetries,along with an atypical{200}crystallographic reflection,confirming diaphite formation in 5%and 10%N-doped UNCD films,while high-er doping levels(15%and 20%)result in extensive graphitization.Raman spectroscopy tracks the evolution of sp^(2)bonding with increasing nitrogen content,while atomic force microscopy and X-ray diffraction indicate a consistent diamond grain size of~8 nm.Cryogenic electronic transport measurements reveal a conductivity increase from 8.72 to 708 S/cm as the nitrogen dop-ing level increases from 5%to 20%,which is attributed to defect-mediated carrier transport and 3D weak localization.The res-ulting conductivity is three orders of magnitude higher than previously reported.These findings establish a direct correlation between diaphite structural polymorphism and tunable electronic properties in nitrogen-doped UNCD films,offering new ways for defect-engineering diamond-based electronic materials.展开更多
O484.1 2000010458激光辅助化学气相沉积金刚石薄膜实验研究=Synthesisof diamond films by laser-assistedchemical vapour deposition[刊,中]/任德明,胡孝勇,刘逢梅,赵景山,王楠楠,马祖光（哈尔滨工业大学光电子技术研究所.黑龙江,哈...O484.1 2000010458激光辅助化学气相沉积金刚石薄膜实验研究=Synthesisof diamond films by laser-assistedchemical vapour deposition[刊,中]/任德明,胡孝勇,刘逢梅,赵景山,王楠楠,马祖光（哈尔滨工业大学光电子技术研究所.黑龙江,哈尔滨（150001））//光电子·激光.—1998,9（6）.—446-449采用激光辅助化学气相沉积法合成了厚度为15μm的金刚石薄膜。实验结果表明:以丙酮为碳源气体,并用XeCl（308 nm）准分子激光解离,H<sub>2</sub>用灯丝进行预先解离,适当选择和控制各种实验参数,可获得高质量的金刚石薄膜。还讨论了衬底温度以及灯丝温度等实验参数对薄膜生长速率与薄膜质量的影响。图9表1参8（郑锦玉）O484.2 2000010459离化团束沉积中的分子动力学模拟=Molecular dynamicssimulation in ionized clusterbeams deposition[刊,中]/张豪,夏宗宁（清华大学材料科学与工程系.北京（100084））//人工晶体学报.—1998,27（4）.展开更多
A Ti interlayer with thickness about 300 nm was sputtered on Cu microchannels, followed by an ultrasonic seeding with nanodiamond powders. Adherent diamond film with crystalline grains close to thermal equilibrium sha...A Ti interlayer with thickness about 300 nm was sputtered on Cu microchannels, followed by an ultrasonic seeding with nanodiamond powders. Adherent diamond film with crystalline grains close to thermal equilibrium shape was tightly deposited by hot-filament chemical vapor deposition(HF-CVD). The nucleation and growth of diamond were investigated with micro-Raman spectroscope and field emission scanning electron microscope(FE-SEM) with energy dispersive X-ray detector(EDX). Results show that the nucleation density is found to be up to 1010 cm-2. The enhancement of the nucleation kinetics can be attributed to the nanometer rough Ti interlayer surface. An improved absorption of nanodiamond particles is found, which act as starting points for the diamond nucleation during HF-CVD process. Furthermore, finite element simulation was conducted to understand the thermal management properties of prepared diamond/Cu microchannel heat sink.展开更多
文摘Nitrogen doping in chemical vapor deposition-derived ultrananocrystalline diamond(UNCD)films in-creases the electronic conductivity,yet its microstructural effects on electron transport are insufficiently understood.We investigated the formation of nitrogen-induced diaph-ite structures(hybrid diamond-graphite phases)and their role in changing the conductivity.Nitrogen doping in a hy-drogen-rich plasma environment promotes the emergence of unique sp^(3)-sp^(2)bonding interfaces,where diamond grains are covalently integrated with graphitic domains,facilitating a structure-driven electronic transition.High-resolution transmis-sion electron microscopy and selected area electron diffraction reveal five-fold,six-fold and twelve-fold symmetries,along with an atypical{200}crystallographic reflection,confirming diaphite formation in 5%and 10%N-doped UNCD films,while high-er doping levels(15%and 20%)result in extensive graphitization.Raman spectroscopy tracks the evolution of sp^(2)bonding with increasing nitrogen content,while atomic force microscopy and X-ray diffraction indicate a consistent diamond grain size of~8 nm.Cryogenic electronic transport measurements reveal a conductivity increase from 8.72 to 708 S/cm as the nitrogen dop-ing level increases from 5%to 20%,which is attributed to defect-mediated carrier transport and 3D weak localization.The res-ulting conductivity is three orders of magnitude higher than previously reported.These findings establish a direct correlation between diaphite structural polymorphism and tunable electronic properties in nitrogen-doped UNCD films,offering new ways for defect-engineering diamond-based electronic materials.
文摘O484.1 2000010458激光辅助化学气相沉积金刚石薄膜实验研究=Synthesisof diamond films by laser-assistedchemical vapour deposition[刊,中]/任德明,胡孝勇,刘逢梅,赵景山,王楠楠,马祖光（哈尔滨工业大学光电子技术研究所.黑龙江,哈尔滨（150001））//光电子·激光.—1998,9（6）.—446-449采用激光辅助化学气相沉积法合成了厚度为15μm的金刚石薄膜。实验结果表明:以丙酮为碳源气体,并用XeCl（308 nm）准分子激光解离,H<sub>2</sub>用灯丝进行预先解离,适当选择和控制各种实验参数,可获得高质量的金刚石薄膜。还讨论了衬底温度以及灯丝温度等实验参数对薄膜生长速率与薄膜质量的影响。图9表1参8（郑锦玉）O484.2 2000010459离化团束沉积中的分子动力学模拟=Molecular dynamicssimulation in ionized clusterbeams deposition[刊,中]/张豪,夏宗宁（清华大学材料科学与工程系.北京（100084））//人工晶体学报.—1998,27（4）.
基金Project(21271188) supported by the National Natural Science Foundation of China
文摘A Ti interlayer with thickness about 300 nm was sputtered on Cu microchannels, followed by an ultrasonic seeding with nanodiamond powders. Adherent diamond film with crystalline grains close to thermal equilibrium shape was tightly deposited by hot-filament chemical vapor deposition(HF-CVD). The nucleation and growth of diamond were investigated with micro-Raman spectroscope and field emission scanning electron microscope(FE-SEM) with energy dispersive X-ray detector(EDX). Results show that the nucleation density is found to be up to 1010 cm-2. The enhancement of the nucleation kinetics can be attributed to the nanometer rough Ti interlayer surface. An improved absorption of nanodiamond particles is found, which act as starting points for the diamond nucleation during HF-CVD process. Furthermore, finite element simulation was conducted to understand the thermal management properties of prepared diamond/Cu microchannel heat sink.
