期刊文献+
共找到39篇文章
< 1 2 >
每页显示 20 50 100
Plasma density enhancement in radio-frequency hollow electrode discharge
1
作者 贺柳良 何锋 欧阳吉庭 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第4期44-51,共8页
The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results s... The plasma density enhancement outside hollow electrodes in capacitively coupled radio-frequency(RF) discharges is investigated by a two-dimensional(2D) particle-in-cell/Monte-Carlo collision(PIC/MCC) model. Results show that plasma exists inside the cavity when the sheath inside the hollow electrode hole is fully collapsed, which is an essential condition for the plasma density enhancement outside hollow electrodes. In addition, the existence of the electron density peak at the orifice is generated via the hollow cathode effect(HCE), which plays an important role in the density enhancement. It is also found that the radial width of bulk plasma at the orifice affects the magnitude of the density enhancement, and narrow radial plasma bulk width at the orifice is not beneficial to obtain high-density plasma outside hollow electrodes.Higher electron density at the orifice, combined with larger radial plasma bulk width at the orifice,causes higher electron density outside hollow electrodes. The results also imply that the HCE strength inside the cavity cannot be determined by the magnitude of the electron density outside hollow electrodes. 展开更多
关键词 RF capacitively coupled plasma sources plasma density enhancement hollow cathodeeffect hollow electrode
下载PDF
Experimental investigation for temperature and emissivity by flame emission spectrum in a cavity of rocket based combined cycle combustor chamber
2
作者 Weiguang Cai Shu Zheng +4 位作者 Yan Wang Bing Liu Shaohua Zhu Li Zhao Qiang Lu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第9期114-122,共9页
Flame temperature and spectral emissivity were the important parameters characterizing the sufficient degree of fuel combustion and the particle radiative characteristics in the Rocket Based Combined Cycle(RBCC)combus... Flame temperature and spectral emissivity were the important parameters characterizing the sufficient degree of fuel combustion and the particle radiative characteristics in the Rocket Based Combined Cycle(RBCC)combustor.To investigate the combustion characteristics of the complex supersonic flame in the RBCC combustor,a new radiation thermometry combined with Levenberg-Marquardt(LM)algorithm and the least squares method was proposed to measure the temperature,emissivity and spectral radiative properties based on the flame emission spectrum.In-situ measurements of the flame temperature,emissivity and spectral radiative properties were carried out in the RBCC direct-connected test bench with laser-induced plasma combustion enhancement(LIPCE)and without LIPCE.The flame average temperatures at fuel global equivalence ratio(a)of 1.0b and 0.6 with LIPCE were 4.51%and 2.08%higher than those without LIPCE.The flame combustion oscillation of kerosene tended to be stable in the recirculation zone of cavity with the thermal and chemical effects of laser induced plasma.The differences of flame temperature at a=1.0b and 0.6 were 503 K and 523 K with LIPCE,which were 20.07%and42.64%lower than those without LIPCE.The flame emissivity with methane assisted ignition was 80.46%lower than that without methane assisted ignition,due to the carbon-hydrogen ratio of kerosene was higher than that of methane.The spectral emissivities at 600 nm with LIPCE were 1.25%,22.2%,and 4.22%lower than those without LIPCE at a=1.0a(with methane assisted ignition),1.0b(without methane assisted ignition)and 0.6.The effect of concentration in the emissivity was removed by normalization to analyze the flame radiative properties in the RBCC combustor chamber.The maximum differences of flame normalized emissivity were 50.91%without LIPCE and 27.53%with LIPCE.The flame radiative properties were stabilized under the thermal and chemical effects of laser induced plasma at a=0.6. 展开更多
关键词 Rocket-based combined-cycle Supersonic combustion Flame temperature measurement EMISSIVITY Laser induced plasma combustion enhancement
下载PDF
Influence of plasma condition on carbon nanotube growth by rf-PECVD 被引量:2
3
作者 Y.H.Man Z.C.Li Z.J.Zhang 《Nano-Micro Letters》 SCIE EI CAS 2010年第1期37-41,共5页
Carbon nanotubes(CNTs)have been synthesized from Ar-CH_4 mixtures using rf-plasma enhanced chemical vapor deposition(rf-PECVD)at 500oC.Reduction gases such as H_2 and NH_3 were found unnecessary for carbon nanotube fo... Carbon nanotubes(CNTs)have been synthesized from Ar-CH_4 mixtures using rf-plasma enhanced chemical vapor deposition(rf-PECVD)at 500oC.Reduction gases such as H_2 and NH_3 were found unnecessary for carbon nanotube formation compared to thermal CVD.The relationship between the growth of CNTs and the plasma condition in PECVD has been investigated by in situ self bias measurement.Plasma conditions were controlled by changing the interelectrode distance,rf power and the applied substrate negative bias.By increasing the interelectrode distance and rf power,the spatial density of CNTs was on a rise as a result of the increase in ions density and self bias.As the applied substrate negative bias increased,the spatial density of CNTs decreased possibly due to the positive ions over bombarding effect. 展开更多
关键词 Carbon nanotube plasma enhanced CVD plasma condition
下载PDF
Influence of the Plasma State on the Formation of Nano Crystalline SiC Films 被引量:1
4
作者 廖波 王静静 +2 位作者 陆姗姗 严辉 王波 《Journal of Beijing Institute of Technology》 EI CAS 2004年第2期123-126,共4页
The influence of the plasma state on the microstructure transformation from amorphous to nano-(crystalline) state is emphasized during the formation of the silicon carbide (SiC) films deposited by the plasma enhanced ... The influence of the plasma state on the microstructure transformation from amorphous to nano-(crystalline) state is emphasized during the formation of the silicon carbide (SiC) films deposited by the plasma enhanced chemical vapor technique. The effect of two key parameters, the working pressure and hydrogen concentration in the gas flow, that perform the dependence by modulating the two essential factors of the plasma state-ions energy and gas composition, is in-depth investigated. The experimental results showed that nanocrystalline SiC films fit for field emitters could be achieved under an appropriate ion energy flow density and gas components in the (plasma.) 展开更多
关键词 NANOCRYSTALLINE Β-SIC plasma enhanced chemical vapour deposition (PECVD) plasma state
下载PDF
The Gas Nucleation Process Study of Anatase TiO_2 in Atmospheric Non-Thermal Plasma Enhanced Chemical Vapor Deposition 被引量:1
5
作者 吴茂水 徐雨 +8 位作者 戴林君 王恬恬 李雪 王德信 郭颖 丁可 黄晓江 石建军 张菁 《Plasma Science and Technology》 SCIE EI CAS CSCD 2014年第1期32-36,共5页
Abstract The gas phase nucleation process of anatase TiO2 in atmospheric non-thermal plasma enhanced chemical vapor deposition is studied. The particles synthesized in the plasma gas phase at different power density w... Abstract The gas phase nucleation process of anatase TiO2 in atmospheric non-thermal plasma enhanced chemical vapor deposition is studied. The particles synthesized in the plasma gas phase at different power density were collected outside of the reactor. The structure of the collected particles has been investigated by field scanning electron microscope (FESEM), X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED). The analysis shows that uniform crystalline nuclei with average size of several nanometers have been formed in the scale of micro second through this reactive atmo- spheric plasma gas process. The crystallinity of the nanoparticles increases with power density. The high density of crystalline nanonuclei in the plasma gas phase and the low gas temperature are beneficial to the fast deposition of the 3D porous anatase TiO2 film. 展开更多
关键词 gas phase nucleation TiO2 nanoparticles plasma enhanced chemical vapordeposition (PECVD) 3D nanostructured films atmospheric pressure
下载PDF
Characteristics and Electrical Properties of SiNx:H Films Fabricated by Plasma-Enhanced Chemical Vapor Deposition 被引量:2
6
作者 凌绪玉 《Journal of Electronic Science and Technology of China》 2005年第3期264-267,共4页
SiNx:H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition (PECVD). Composition and structure characteristics are detected by Fourier transform infrared spectroscopy (FTIR... SiNx:H films with different N/Si ratios are synthesized by plasma-enhanced chemical vapor deposition (PECVD). Composition and structure characteristics are detected by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). It indicates that Si-N bonds increase with increased NH3/SiH4 ratio. Electrical property investigations by I-V measurements show that the prepared films offer higher resistivity and less leakage current with increased N/Si ratio and exhibit entirely insulating properties when N/Si ratio reaches 0.9, which is ascribed to increased Si-N bonds achieved. 展开更多
关键词 silicon nitride films electrical properties I-V measurement plasma enhanced chemical vapor deposition
下载PDF
Structural evolution and optical characterization in argon diluted Si:H thin films obtained by plasma enhanced chemical vapor deposition
7
作者 李志 何剑 +3 位作者 李伟 蔡海洪 龚宇光 蒋亚东 《Journal of Central South University》 SCIE EI CAS 2010年第6期1163-1171,共9页
The structural evolution and optical characterization of hydrogenated silicon(Si:H) thin films obtained by conventional radio frequency(RF) plasma enhanced chemical vapor deposition(PECVD) through decomposition of sil... The structural evolution and optical characterization of hydrogenated silicon(Si:H) thin films obtained by conventional radio frequency(RF) plasma enhanced chemical vapor deposition(PECVD) through decomposition of silane diluted with argon were studied by X-ray diffractometry(XRD),Fourier transform infrared(FTIR) spectroscopy,Raman spectroscopy,transmission electron microscopy(TEM),and ultraviolet and visible(UV-vis) spectroscopy,respectively.The influence of argon dilution on the optical properties of the thin films was also studied.It is found that argon as dilution gas plays a significant role in the growth of nano-crystal grains and amorphous network in Si:H thin films.The structural evolution of the thin films with different argon dilution ratios is observed and it is suggested that argon plasma leads to the nanocrystallization in the thin films during the deposition process.The nanocrystallization initiating at a relatively low dilution ratio is also observed.With the increase of argon portion in the mixed precursor gases,nano-crystal grains in the thin films evolve regularly.The structural evolution is explained by a proposed model based on the energy exchange between the argon plasma constituted with Ar* and Ar+ radicals and the growth regions of the thin films.It is observed that both the absorption of UV-vis light and the optical gap decrease with the increase of dilution ratio. 展开更多
关键词 NANOCRYSTALLIZATION plasma enhanced chemical vapor deposition (PECVD) hydrogenated silicon (Si:H)
下载PDF
Influence of ignition condition on the growth of silicon thin films using plasma enhanced chemical vapour deposition
8
作者 Zhang Hai-Long Liu Feng-Zhen +1 位作者 Zhu Mei-Fang Liu Jin-Long 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第1期314-319,共6页
The influences of the plasma ignition condition in plasma enhanced chemical vapour deposition (PECVD) on the interfaces and the microstructures of hydrogenated microcrystalline Si (μc-Si:H) thin films are invest... The influences of the plasma ignition condition in plasma enhanced chemical vapour deposition (PECVD) on the interfaces and the microstructures of hydrogenated microcrystalline Si (μc-Si:H) thin films are investigated. The plasma ignition condition is modified by varying the ratio of Sill4 to H2 (RH). For plasma ignited with a constant gas ratio, the time-resolved optical emission spectroscopy presents a low value of the emission intensity ratio of Ha to Sill* (Iuα//SiH*) at the initial stage, which leads to a thick amorphous incubation layer. For the ignition condition with a profiling RH, the higher IHα/ISiH* values are realized. By optimizing the RN modulation, a uniform crystallinity along the growth direction and a denser αc-Si:H film can be obtained. However, an excessively high IRα/ISIH* may damage the interface properties, which is indicated by capacitance-voltage (C-V) measurements. Well controlling the ignition condition is critically important for the applications of Si thin films. 展开更多
关键词 plasma enhanced chemical vapour deposition microcrystalline silicon ignition condition
下载PDF
Plasma-Enhanced Atomic Layer Deposition of Amorphous Ga_(2)O_(3) for Solar-Blind Photodetection
9
作者 Ze-Yu Fan Min-Ji Yang +9 位作者 Bo-Yu Fan Andraz Mavric Nadiia Pastukhova Matjaz Valant Bo-Lin Li Kuang Feng Dong-Liang Liu Guang-Wei Deng Qiang Zhou Yan-Bo Li 《Journal of Electronic Science and Technology》 CAS CSCD 2022年第4期331-344,共14页
Wide-bandgap gallium oxide(Ga_(2)O_(3))is one of the most promising semiconductor materials for solar-blind(200 nm to 280 nm)photodetection.In its amorphous form,amorphous gallium oxide(a-Ga_(2)O_(3))maintains its int... Wide-bandgap gallium oxide(Ga_(2)O_(3))is one of the most promising semiconductor materials for solar-blind(200 nm to 280 nm)photodetection.In its amorphous form,amorphous gallium oxide(a-Ga_(2)O_(3))maintains its intrinsic optoelectronic properties while can be prepared at a low growth temperature,thus it is compatible with Si integrated circuits(ICs)technology.Herein,the a-Ga_(2)O_(3) film is directly deposited on pre-fabricated Au interdigital electrodes by plasma enhanced atomic layer deposition(PE-ALD)at a growth temperature of 250°C.The stoichiometric a-Ga_(2)O_(3) thin film with a low defect density is achieved owing to the mild PE-ALD condition.As a result,the fabricated Au/a-Ga_(2)O_(3)/Au photodetector shows a fast time response,high responsivity,and excellent wavelength selectivity for solar-blind photodetection.Furthermore,an ultra-thin MgO layer is deposited by PE-ALD to passivate the Au/a-Ga_(2)O_(3)/Au interface,resulting in the responsivity of 788 A/W(under 254 nm at 10 V),a 250-nm-to-400-nm rejection ratio of 9.2×10^(3),and the rise time and the decay time of 32 ms and 6 ms,respectively.These results demonstrate that the a-Ga_(2)O_(3) film grown by PE-ALD is a promising candidate for high-performance solar-blind photodetection and potentially can be integrated with Si ICs for commercial production. 展开更多
关键词 Amorphous gallium oxide(a-Ga_(2)O_(3)) passivation layer plasma enhanced atomic layer deposition(PE-ALD) responsivity solar-blind photodetector
下载PDF
Synthesis and Characteristics of Fe_3C Nanoparticles Embedded in Amorphous Carbon Matrix 被引量:4
10
作者 YANG Kai-yu XU Wei +2 位作者 ZHANG Yu ZHENG Wei-tao WANG Xin 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2010年第3期348-351,共4页
We proposed a new way to synthesize a nanocomposite consisted of cementite Fe3C nanoparticles and amorphous carbon by radio frequency plasma-enhanced chemical vapor deposition. Transmission electron microscope images ... We proposed a new way to synthesize a nanocomposite consisted of cementite Fe3C nanoparticles and amorphous carbon by radio frequency plasma-enhanced chemical vapor deposition. Transmission electron microscope images show the existence of nanometric dark grains(Fe3C) embedded in a light matrix(amorphous carbon) in the samples. X-ray photoelectron spectroscopy experiment exhibit that the chemical bonding state in the films corresponded to sp3/sp2 amorphous carbon, sp^3 C-N(287.3 eV) and C15 in Fe3C(283.5 eV). With increasing deposition time, the ratio of amorphous carbon increased. The magnetic measurements show that the value of in-lane coercivity increased with increasing carbon matrix concentration(from about 6.56× 10^3 A/m for film without carbon structures to approximately 2.77× 10^4 and 5.81 × 10^4 AJm for nanocomposite films at room temperature and 10 K, respectively). The values of saturation magnetization for the synthesized nanocomposites were lower than that of the bulk Fe3C ( 140 Am^2/kg). 展开更多
关键词 Fe3C nanoparticle Amorphous carbon plasma enhancement chemical vapor deposition(PECVD) Magnetic property
下载PDF
Growth characteristics of amorphous-layer-free nanocrystalline silicon films fabricated by very high frequency PECVD at 250 ℃ 被引量:3
11
作者 郭艳青 黄锐 +3 位作者 宋捷 王祥 宋超 张奕雄 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第6期389-393,共5页
Amorphous-layer-free nanocrystalline silicon films were prepared by a very high frequency plasma enhanced chem-ical vapor deposition (PECVD) technique using hydrogen-diluted Sill4 at 250 ℃. The dependence of the cr... Amorphous-layer-free nanocrystalline silicon films were prepared by a very high frequency plasma enhanced chem-ical vapor deposition (PECVD) technique using hydrogen-diluted Sill4 at 250 ℃. The dependence of the crystallinity of the film on the hydrogen dilution ratio and the film thickness was investigated. Raman spectra show that the thickness of the initial amorphous incubation layer on silicon oxide gradually decreases with increasing hydrogen dilution ratio. High-resolution transmission electron microscopy reveals that the initial amorphous incubation layer can be completely eliminated at a hydrogen dilution ratio of 98%, which is lower than that needed for the growth of amorphous-layer-free nanocrystalline silicon using an excitation frequency of 13.56 MHz. More studies on the microstructure evolution of the initial amorphous incubation layer with hydrogen dilution ratios were performed using Fourier-transform infrared spectroscopy. It is suggested that the high hydrogen dilution, as well as the higher plasma excitation frequency, plays an important role in the formation of amorphous-layer-free nanocrystalline silicon films. 展开更多
关键词 nanocrystalline silicon amorphous incubation layer plasma enhanced chemical vapordeposition
下载PDF
Mechanical properties of AISI 1045 ceramic coated materials by nano indentation and crack opening displacement method 被引量:1
12
作者 王燕荣 王一奇 惠志鹏 《Journal of Central South University》 SCIE EI CAS 2012年第11期3023-3027,共5页
Abstract: An effective approach was conducted for estimating fracture toughness using the crack opening displacement (COD) method for plasma enhanced chemical vapor deposition (PECVD) coating materials. For this ... Abstract: An effective approach was conducted for estimating fracture toughness using the crack opening displacement (COD) method for plasma enhanced chemical vapor deposition (PECVD) coating materials. For this evaluation, an elastoplastic analysis was used to estimate critical COD values for single edge notched bending (SENB) specimens. The relationship between fracture toughness (Kic) and critical COD for SENB specimens was obtained. Microstructure of the interface between AleO3-TiO2 composite ceramic coatings and AISI 1045 steel substrates was studied by using scanning electron microscope (SEM). Chemical compositions were clarified by energy-dispersive X-ray spectroscopy (EDS). The results show that the interface between of Al203-TiO2 and substrate has mechanical combining. The nanohardness of the coatings can reach 1 200 GPa examined by nanoindentation. The Klc was calculated according to this relationship from critical COD. The bending process produces a significant relationship of COD independent of the axial force applied. Fractographic analysis was conducted to determine the crack length. From the physical analysis of nanoindentation curves, the elastic modulus of 1045/AI2O3-TiO2 is 180 GPa for the 50 μm film. The highest value of fracture toughness for 1045/A1203-TiO2-250 μm is 348 MPa·mv2. 展开更多
关键词 crack opening displacement (COD) single edge notched bending (SENB) plasma enhanced chemical vapor deposition(PECVD) fracture toughness NANOINDENTATION
下载PDF
Enhancing the expansion of a plasma shockwave by crater-induced laser refocusing in femtosecond laser ablation of fused silica 被引量:7
13
作者 QINGSONG WANG LAN JIANG +6 位作者 JINGYA SUN CHANGJI PAN WEINA HAN GUOYAN WANG HAO ZHANG COSTAS P.GRIGOROPOULOS YONGFENG LU 《Photonics Research》 SCIE EI 2017年第5期488-493,共6页
The dynamics of plasma and shockwave expansion during two femtosecond laser pulse ablation of fused silica are studied using a time-resolved shadowgraph imaging technique. The experimental results reveal that during t... The dynamics of plasma and shockwave expansion during two femtosecond laser pulse ablation of fused silica are studied using a time-resolved shadowgraph imaging technique. The experimental results reveal that during the second pulse irradiation on the crater induced by the first pulse, the expansion of the plasma and shockwave is enhanced in the longitudinal direction. The plasma model and Fresnel diffraction theory are combined to calculate the laser intensity distribution by considering the change in surface morphology and transient material properties. The theoretical results show that after the free electron density induced by the rising edge of the pulse reaches the critical density, the originally transparent surface is transformed into a transient high-reflectivity surface(metallic state). Thus, the crater with a concave-lens-like morphology can tremendously reflect and refocus the latter part of the laser pulse, leading to a strong laser field with an intensity even higher than the incident intensity. This strong refocused laser pulse results in a stronger laser-induced air breakdown and enhances the subsequent expansion of the plasma and shockwave. In addition, similar shadowgraphs are also recorded in the single-pulse ablation of a concave microlens, providing experimental evidence for the enhancement mechanism. 展开更多
关键词 exp enhancing the expansion of a plasma shockwave by crater-induced laser refocusing in femtosecond laser ablation of fused silica
原文传递
mc-Si:H/c-Si solar cell prepared by PECVD
14
作者 XU Ying LIAO Xianbo DIAO Hongwei Li Xudong ZENG Xiangbo LIU Xiaoping WANG Minhua WANG Wenjing 《Rare Metals》 SCIE EI CAS CSCD 2006年第z1期176-179,共4页
Hetero-junction solar cells with an mc-Si:H window layer were achieved. The open voltage is increased while short current is decreased with increasing the mc-Si:H layer′s thickness of emitter layer. The highest of Vo... Hetero-junction solar cells with an mc-Si:H window layer were achieved. The open voltage is increased while short current is decreased with increasing the mc-Si:H layer′s thickness of emitter layer. The highest of Voc of 597 mV has obtained. When fixed the thickness of 30 nm, changing the N type from amorphous silicon layer to micro-crystalline layer, the efficiency of the hetero-junction solar cells is increased. Although the hydrogen etching before deposition enables the c-Si substrates to become rough by AFM images, it enhances the formation of epitaxial-like micro-crystalline silicon and better parameters of solar cell can be obtained by implying this process. The best result of efficiency is 13.86% with the Voc of 549.8 mV, Jsc of 32.19 mA·cm-2 and the cell′s area of 1 cm2. 展开更多
关键词 solar cell hetero-junction amorphous silicon plasma enhanced CVD
下载PDF
Ultra-thin a-SiN_x protective overcoats for hard disks and read/write heads
15
作者 丁万昱 徐军 +2 位作者 陆文琪 邓新绿 董闯 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1570-1573,共4页
This paper reports that amorphous silicon nitride (a-SiNx) overcoats were deposited at room temperature by microwave ECR plasma enhanced unbalanced magnetron sputtering. The 2 nm a-SiNs overcoat has better anti-corr... This paper reports that amorphous silicon nitride (a-SiNx) overcoats were deposited at room temperature by microwave ECR plasma enhanced unbalanced magnetron sputtering. The 2 nm a-SiNs overcoat has better anti-corrosion properties than that of reference a-CNx overcoats (2 4.5 nm). The superior anti-corrosion performance is attributed to its stoichiometric bond structure, where 94.8% Si atoms form Si-N asymmetric stretching vibration bonds. The N/Si ratio is 1.33 as in the stoichiometry of Si3N4 and corresponds to the highest hardness of 25.0 GPa. The surface is atomically smooth with RMS 〈 0.2 nm. The ultra-thin a-SiNx overcoats are promising for hard disks and read/write heads protective coatings. 展开更多
关键词 hard disk overcoat ULTRA-THIN a-SiNx plasma enhanced magnetron sputtering
下载PDF
Effect of ammonia gas etching on growth of vertically aligned carbon nanotubes/nanofibers
16
作者 Sang-Gook KIM Sooh-Yung KIM Hyung-Woo LEE 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第A01期130-134,共5页
The etching effect of ammonia (NH3) on the growth of vertically aligned nanotubes/nanofibers (CNTs) was investigated by direct-current plasma enhanced chemical vapor deposition (DC-PECVD). NH3 gas etches Ni cata... The etching effect of ammonia (NH3) on the growth of vertically aligned nanotubes/nanofibers (CNTs) was investigated by direct-current plasma enhanced chemical vapor deposition (DC-PECVD). NH3 gas etches Ni catalyst layer to form nanoscale islands while NH3 plasma etches the deposited amorphous carbon. Based on the etching effect of NH3 gas on Ni catalyst, the differences of growing bundles of CNTs and single strand CNTs were discussed; specifically, the amount of optimal NH3 gas etching is different between bundles of CNTs and single strand CNTs. In contrast to the CNT carpet growth, the single strand CNT growth requires shorter etching time (5 min) than large catalytic patterns (10 rain) since nano dots already form catalyst islands for CNT growth. Through removing the plasma pretreatment process, the damage from being exposed at high temperature substrate occurring during the plasma generation time is minimized. High resolution transmission electron microscopy (HTEM) shows fishbone structure of CNTs grown by PECVD. 展开更多
关键词 carbon nanotube ammonia etching nickel catalyst plasma enhanced chemical vapor deposition (PECVD)
下载PDF
A simple method to synthesize worm-like AlN nanowires and its field emission studies
17
作者 Qi Liang Meng-Qi Yang +1 位作者 Chang-Hao Wang Ru-Zhi Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第8期469-474,共6页
The worm-like AlN nanowires are fabricated by the plasma-enhanced chemical vapor deposition(PECVD)on Si substrates through using Al powder and N2 as precursors,CaF2 as fluxing medium,Au as catalyst,respectively.The as... The worm-like AlN nanowires are fabricated by the plasma-enhanced chemical vapor deposition(PECVD)on Si substrates through using Al powder and N2 as precursors,CaF2 as fluxing medium,Au as catalyst,respectively.The as-grown worm-like AlN nanowires each have a polycrystalline and hexagonal wurtzite structure.Their diameters are about 300 nm,and the lengths are over 10μm.The growth mechanism of worm-like AlN nanowires is discussed.Hydrogen plasma plays a very important role in forming the polycrystalline structure and rough surfaces of worm-like AlN nanowires.The worm-like AlN nanowires exhibit an excellent field-emission(FE)property with a low turn-on field of 4.5 V/μm at a current density of 0.01 mA/cm^(2) and low threshold field of 9.9 V/μm at 1 mA/cm^(2).The emission current densities of worm-like AlN nanowires each have a good stability.The enhanced FE properties of worm-like AlN nanowires may be due to their polycrystalline and rough structure with nanosize and high aspect ratio.The excellent FE properties of worm-like AlN nanowires can be explained by a grain boundary conduction mechanism.The results demonstrate that the worm-like AlN nanowires prepared by the proposed simple and the PECVD method possesses the potential applications in photoelectric and field-emission devices. 展开更多
关键词 worm-like aluminum nitride nanowires growth mechanism plasma enhanced chemical vapor deposition field-emission property
下载PDF
Influence of total gas flow rate on microcrystalline silicon films prepared by VHF-PECVD
18
作者 高艳涛 张晓丹 +4 位作者 赵颖 孙健 朱峰 魏长春 陈飞 《Chinese Physics B》 SCIE EI CAS CSCD 2006年第5期1110-1113,共4页
Hydrogenated microcrystalline silicon (μc-Si:H) films are fabricated by very high frequency plasma enhanced chemical vapour deposition (VHF-PECVD) at a silane concentration of 7% and a varying total gas flow ra... Hydrogenated microcrystalline silicon (μc-Si:H) films are fabricated by very high frequency plasma enhanced chemical vapour deposition (VHF-PECVD) at a silane concentration of 7% and a varying total gas flow rate (H2+SiH4). Relations between the total gas flow rate and the electrical and structural properties as well as deposition rate of the films are studied. The results indicate that with the total gas flow rate increasing the photosensitivity and deposition rate increase, but the crystalline volume fraction (Xc) and dark conductivity decrease. And the intensity of (220) peak first increases then decreases with the increase of the total gas flow rate. The cause for the changes in the structure and deposition rate of the films with the total gas flow rate is investigated using optical emission spectroscopy (OES). 展开更多
关键词 very high frequency plasma enhanced chemical vapour deposition intrinsic microcrystalline silicon gas flow rate
下载PDF
Effect of Chamber Conditions and Substrate Type on PECVD of SiGeSn Films
19
作者 Venkat Hariharan Jignesh Vanjaria +2 位作者 Arul Chakkaravarthi Arjunan Gary S. Tompa Hongbin Yu 《Crystal Structure Theory and Applications》 2021年第3期39-56,共18页
In the past studies have shown that the addition of Ge and Sn into Si lattice to form SiGeSn enhances its carrier mobility and band-gap properties. Conventionally SiGeSn epitaxial films are grown using Ultra-High Vacu... In the past studies have shown that the addition of Ge and Sn into Si lattice to form SiGeSn enhances its carrier mobility and band-gap properties. Conventionally SiGeSn epitaxial films are grown using Ultra-High Vacuum (UHV) conditions with pressures ranging from 10<sup>-8</sup> torr to 10<sup>-10</sup> torr which makes high volume manufacturing very expensive. On the contrary, the use of low-pressure CVD processes (vacuum levels of 10<sup>-2</sup> torr to 10<sup>-4</sup> torr) is economically more viable and yields faster deposition of SiGeSn films. This study outlines the use of a cost-effective Plasma Enhanced Chemical Vapor Deposition (PECVD) reactor to study the impact of substrate temperature and substrate type on the growth and properties of polycrystalline SiGeSn films. The onset of polycrystallinity in the films is attributed to the oxygen-rich PECVD chamber conditions explained using the Volmer-Weber (3D island) mechanism. The properties of the films were characterized using varied techniques to understand the impact of the substrate on film composition, thickness, crystallinity, and strain. 展开更多
关键词 Thin Film Growth Volmer-Weber Mechanism plasma Enhanced Chemical Vapor Deposition Silicon Photonics Carrier Mobility Band-Gap Engineering Semimetal Alloys
下载PDF
Synthesis of graphene on a Ni film by radio-frequency plasma-enhanced chemical vapor deposition 被引量:8
20
作者 QI JunLei ZHANG LiXia +3 位作者 CAO Jian ZHENG WeiTao WANG Xin FENG JiCai 《Chinese Science Bulletin》 SCIE EI CAS 2012年第23期3040-3044,共5页
Large-area single-or multilayer graphene of high quality is synthesized on Ni films by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) at a relatively low temperature (650℃).In the deposition pro... Large-area single-or multilayer graphene of high quality is synthesized on Ni films by radio-frequency plasma-enhanced chemical vapor deposition (RF-PECVD) at a relatively low temperature (650℃).In the deposition process,a trace amount of CH4 gas (2-8 sccm (sccm denotes standard cubic centimeter per minute at STP)) is introduced into the PECVD chamber and only a short deposition time (30-60 s) is used.Single-or multilayer graphene is obtained because carbon atoms from the discharging CH4 diffuse into the Ni film and then segregate out at its surface.The layer number of the obtained graphene increases when the deposition time or CH4 gas flow rate is increased.This investigation shows that PECVD is a simple,low-cost,and effective technique to synthesize large-area single-or multilayer graphene,which has potential for application as electronic devices. 展开更多
关键词 GRAPHENE PECVD large-area CH4 plasma—enhanced
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部