Using plasma enhanced chemical vapor deposition（PECVD） at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects o...Using plasma enhanced chemical vapor deposition（PECVD） at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects of seeding processes on the growth ofμc-Si1-xGex:H i-layers and the performance ofμc-Si1-xGex:H p-i-n single junction solar cells are investigated.By applying this seeding method,theμc-Si1-xGex:H solar cell shows a significant improvement in short circuit current density(Jsc) and fill factor（FF） with an acceptable performance of blue response as aμc-Si:H solar cell even when the Ge content x increases up to 0.3.Finally,an improved efficiency of 7.05%is achieved for theμc-Si0.7Ge0.3:H solar cell.展开更多
In recent years,silicon(Si)and germanium(Ge)materials have been considered as promising highperformance anode materials for lithium-ion batteries due to their high theoretical capacities.It is of great importance to d...In recent years,silicon(Si)and germanium(Ge)materials have been considered as promising highperformance anode materials for lithium-ion batteries due to their high theoretical capacities.It is of great importance to design and synthesize micro/nanostructured Si and Ge materials.In this work,we demonstrated that Si,Ge and SiGe micro/nanowires can be continuously synthesized from their oxides precursors through molten salt electrodeposition.The electrochemical synthesis processes have been investigated systematically,and the deposited Si,Ge and SiGe micro/nanowires have been characterized and compared.The results show that the micro/nanostructured Si and Ge materials with tunable morphology can be facilely and continuously produced via molten salt electrodeposition.The electrodeposition process generally includes calcium oxide-assisted dissolution and electrodeposition processes,and the morphologies of the deposited Si and Ge products can be controlled by varying conditions.Si micro/nanowires,Si films,Ge micro/nanowires,and Ge particles can be continuously synthesized in a controlled manner.展开更多
Based on the exact resultant solution of two-dimensional Poisson＇s equation in strained Si and Si1-xCex layer, a simple and accurate two-dimensional.analytical model including surface channel potential, surface chann...Based on the exact resultant solution of two-dimensional Poisson＇s equation in strained Si and Si1-xCex layer, a simple and accurate two-dimensional.analytical model including surface channel potential, surface channel electric field, threshold voltage and subthreshold swing for fully depleted gate stack strained Si on silicon-germanium-on-insulator （SGOI） MOSFETs has been developed. The results show that this novel structure can suppress the short channel effects （SCE）, the drain-induced barrier-lowering （DIBL） and improve the subthreshold performance in nanoelectronics application. The model is verified by numerical simulation. The model provides the basic designing guidance of gate stack strained Si on SGOI MOSFETs.展开更多
In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,P.Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 835, 820, 8...In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,P.Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 835, 820, 810 and 805 nm with molar absorptivities of 2.64x104, 2.54x104 3.51x104 and 2.25x104 L.mol-1'cm-1 and linear ranges of 0-30,0-15,0-10 and 0-30 μg/25mL, The method was applied to the determinations of As, P and Si in alloyed steel.展开更多
An epitaxial SixGey layer on a silicon substrate was quantitatively evaluated using rocking curve (RC) and reciprocal space map (RSM) obtained by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (E...An epitaxial SixGey layer on a silicon substrate was quantitatively evaluated using rocking curve (RC) and reciprocal space map (RSM) obtained by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) in conjunction with transmission electron microscopy (TEM), and EDS in conjunction with scanning electron microscopy (SEM). To evaluate the relative deviation of the quantitative analysis results obtained by the RC, RSM, SEM/EDS, and TEM/EDS methods, a standard sample comprising a Si0.7602Ge0.2398 layer on a Si substrate was used. The correction factor (K-factor) for each technique was determined using multiple measurements. The average and standard deviation of the atomic fraction of Ge in the Si0.7602Ge0.2398 standard sample, as obtained by the RC, RSM, TEM/EDS, and SEM/EDS methods, were 0.2463 ± 0.0016, 0.2460 ± 0.0015, 0.2350 ± 0.0156, and 0.2433 ± 0.0059, respectively. The correction factors for the RC, RSM, TEM/EDS, and SEM/EDS methods were 0.9740, 0.9740, 1.0206, and 0.9856, respectively. The SixGey layer on a silicon substrate was quantitatively evaluated using the RC, RSM, and EDS/TEM methods. The atomic fraction of Ge in the epitaxial SixGey layer, as evaluated by the RC and RSM methods, was 0.1833 ± 0.0007, 0.1792 ± 0.0001, and 0.1631 ± 0.0105, respectively. After evaluating the results of the atomic fraction of Ge in the epitaxial layer, the error was very small, i.e., less than 3%. Thus, the RC, RSM, TEM/EDS, and SEM/EDS methods are suitable for evaluating the composition of Ge in epitaxial layers. However, the thickness of the epitaxial layer, whether the layer is strained or relaxed, and whether the area detected in the TEM and SEM analyses is consistent must be considered.展开更多
Strain-relaxed SiGe is an attractive material for use as a substrate of strained Si, in which carrier mobility is higher than that of bulk Si. The concept of this study is the use of porous Si as a sponge like substra...Strain-relaxed SiGe is an attractive material for use as a substrate of strained Si, in which carrier mobility is higher than that of bulk Si. The concept of this study is the use of porous Si as a sponge like substrate so that a SiGe lattice can relax without introducing dislocations. We produced porous Si specimens by electrochemical anodization and annealed them under a H2 atmosphere. Then, SiGe thin films were grown by gas-source molecular beam epitaxy. We observed the microstructure of the specimens using transmission electron microscopy. The result showed that we succeeded in producing a single-crys- tal continuous Si0.73Ge0.27 film with a 10% relaxation ratio and a low dislocation density on porous Si.展开更多
作为硅光子集成芯片中基本无源器件的硅基光波导是进行光信号传输的通道,其具有良好的性能,且与CMOS(Complementary Metal Oxide Semiconductor)工艺相兼容因而得到广泛应用。用于电信和数据中心的硅光子集成电路已逐步走向商业化。近年...作为硅光子集成芯片中基本无源器件的硅基光波导是进行光信号传输的通道,其具有良好的性能,且与CMOS(Complementary Metal Oxide Semiconductor)工艺相兼容因而得到广泛应用。用于电信和数据中心的硅光子集成电路已逐步走向商业化。近年来,中红外波段在自由空间通信、传感以及环境监测等领域的潜在应用受到研究者们的广泛关注。文中分析了中红外硅基光波导的研究现状,归纳了SOI(Silicon on Insulator)、GOSI(Ge-on-SOI)、SOS(Si on Sapphire)、GOS(Ge-on-Si)、SGOS(SiGe-on-Si)、SON(Si-on Si_(3)N_(4))、GON(Ge-on Si_(3)N_(4))等波导材料平台和SOPS(Si on Porous Si)、Undercut、Pedestal、Freestanding、Suspended、LOCOS(Local Oxidation of Silicon)以及等离子体结构等制造工艺平台的研究成果。迄今为止,多数单晶硅在MIR(Mid-Infrared)平台的传播损耗大约在0.7~3.0 dB·cm^(-1)。文中讨论并对比了不同类型波导的应用前景,为中红外硅基光波导的研发、应用和商业化提供了参考。展开更多
The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive positi...The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.展开更多
基金supportedbytheNationalBasicResearch Program ofChina(Nos.2011CBA00705,2011CBA00706,2011CBA00707)the Natural Science Foundation of Tianjin(No.12JCQNJC01000)the Fundamental Research Funds for the Central Universities
文摘Using plasma enhanced chemical vapor deposition（PECVD） at 13.56 MHz,a seed layer is fabricated at the initial growth stage of the hydrogenated microcrystalline silicon germanium(μc-Si1-xGex:H) i-layer.The effects of seeding processes on the growth ofμc-Si1-xGex:H i-layers and the performance ofμc-Si1-xGex:H p-i-n single junction solar cells are investigated.By applying this seeding method,theμc-Si1-xGex:H solar cell shows a significant improvement in short circuit current density(Jsc) and fill factor（FF） with an acceptable performance of blue response as aμc-Si:H solar cell even when the Ge content x increases up to 0.3.Finally,an improved efficiency of 7.05%is achieved for theμc-Si0.7Ge0.3:H solar cell.
基金the Shanghai Rising-Star Program(19QA1403600)the National Natural Science Foundation of China(Nos.51974181+2 种基金51574164)the Iron and Steel Joint Research Found of National Natural Science Foundation and China Baowu Steel Group Corporation Limited(U1860203)the authors also thank the CAS Interdisciplinary In novation Team for financial support.
文摘In recent years,silicon(Si)and germanium(Ge)materials have been considered as promising highperformance anode materials for lithium-ion batteries due to their high theoretical capacities.It is of great importance to design and synthesize micro/nanostructured Si and Ge materials.In this work,we demonstrated that Si,Ge and SiGe micro/nanowires can be continuously synthesized from their oxides precursors through molten salt electrodeposition.The electrochemical synthesis processes have been investigated systematically,and the deposited Si,Ge and SiGe micro/nanowires have been characterized and compared.The results show that the micro/nanostructured Si and Ge materials with tunable morphology can be facilely and continuously produced via molten salt electrodeposition.The electrodeposition process generally includes calcium oxide-assisted dissolution and electrodeposition processes,and the morphologies of the deposited Si and Ge products can be controlled by varying conditions.Si micro/nanowires,Si films,Ge micro/nanowires,and Ge particles can be continuously synthesized in a controlled manner.
基金Project supported by the National Natural Science Foundation of China (Grant Nos. 60976068 and 60936005)the Cultivation Fund of the Key Scientific and Technical Innovation Project, Ministry of Education of China (Grant No. 708083)the Specialized Research Fund for the Doctoral Program of Higher Education of China (Grant No. 200807010010)
文摘Based on the exact resultant solution of two-dimensional Poisson＇s equation in strained Si and Si1-xCex layer, a simple and accurate two-dimensional.analytical model including surface channel potential, surface channel electric field, threshold voltage and subthreshold swing for fully depleted gate stack strained Si on silicon-germanium-on-insulator （SGOI） MOSFETs has been developed. The results show that this novel structure can suppress the short channel effects （SCE）, the drain-induced barrier-lowering （DIBL） and improve the subthreshold performance in nanoelectronics application. The model is verified by numerical simulation. The model provides the basic designing guidance of gate stack strained Si on SGOI MOSFETs.
文摘In the media of 0.66,0.96, 2. 16 and 0.54 mol/L ofH2SO4,the heteropoly acids of As,P.Si and Ge are separately reduced to corresponding heteropoly blues by gibberellin, which exhibit maxirnum absorptions at 835, 820, 810 and 805 nm with molar absorptivities of 2.64x104, 2.54x104 3.51x104 and 2.25x104 L.mol-1'cm-1 and linear ranges of 0-30,0-15,0-10 and 0-30 μg/25mL, The method was applied to the determinations of As, P and Si in alloyed steel.
文摘An epitaxial SixGey layer on a silicon substrate was quantitatively evaluated using rocking curve (RC) and reciprocal space map (RSM) obtained by powder X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) in conjunction with transmission electron microscopy (TEM), and EDS in conjunction with scanning electron microscopy (SEM). To evaluate the relative deviation of the quantitative analysis results obtained by the RC, RSM, SEM/EDS, and TEM/EDS methods, a standard sample comprising a Si0.7602Ge0.2398 layer on a Si substrate was used. The correction factor (K-factor) for each technique was determined using multiple measurements. The average and standard deviation of the atomic fraction of Ge in the Si0.7602Ge0.2398 standard sample, as obtained by the RC, RSM, TEM/EDS, and SEM/EDS methods, were 0.2463 ± 0.0016, 0.2460 ± 0.0015, 0.2350 ± 0.0156, and 0.2433 ± 0.0059, respectively. The correction factors for the RC, RSM, TEM/EDS, and SEM/EDS methods were 0.9740, 0.9740, 1.0206, and 0.9856, respectively. The SixGey layer on a silicon substrate was quantitatively evaluated using the RC, RSM, and EDS/TEM methods. The atomic fraction of Ge in the epitaxial SixGey layer, as evaluated by the RC and RSM methods, was 0.1833 ± 0.0007, 0.1792 ± 0.0001, and 0.1631 ± 0.0105, respectively. After evaluating the results of the atomic fraction of Ge in the epitaxial layer, the error was very small, i.e., less than 3%. Thus, the RC, RSM, TEM/EDS, and SEM/EDS methods are suitable for evaluating the composition of Ge in epitaxial layers. However, the thickness of the epitaxial layer, whether the layer is strained or relaxed, and whether the area detected in the TEM and SEM analyses is consistent must be considered.
文摘Strain-relaxed SiGe is an attractive material for use as a substrate of strained Si, in which carrier mobility is higher than that of bulk Si. The concept of this study is the use of porous Si as a sponge like substrate so that a SiGe lattice can relax without introducing dislocations. We produced porous Si specimens by electrochemical anodization and annealed them under a H2 atmosphere. Then, SiGe thin films were grown by gas-source molecular beam epitaxy. We observed the microstructure of the specimens using transmission electron microscopy. The result showed that we succeeded in producing a single-crys- tal continuous Si0.73Ge0.27 film with a 10% relaxation ratio and a low dislocation density on porous Si.
文摘作为硅光子集成芯片中基本无源器件的硅基光波导是进行光信号传输的通道,其具有良好的性能,且与CMOS(Complementary Metal Oxide Semiconductor)工艺相兼容因而得到广泛应用。用于电信和数据中心的硅光子集成电路已逐步走向商业化。近年来,中红外波段在自由空间通信、传感以及环境监测等领域的潜在应用受到研究者们的广泛关注。文中分析了中红外硅基光波导的研究现状,归纳了SOI(Silicon on Insulator)、GOSI(Ge-on-SOI)、SOS(Si on Sapphire)、GOS(Ge-on-Si)、SGOS(SiGe-on-Si)、SON(Si-on Si_(3)N_(4))、GON(Ge-on Si_(3)N_(4))等波导材料平台和SOPS(Si on Porous Si)、Undercut、Pedestal、Freestanding、Suspended、LOCOS(Local Oxidation of Silicon)以及等离子体结构等制造工艺平台的研究成果。迄今为止,多数单晶硅在MIR(Mid-Infrared)平台的传播损耗大约在0.7~3.0 dB·cm^(-1)。文中讨论并对比了不同类型波导的应用前景,为中红外硅基光波导的研发、应用和商业化提供了参考。
基金Project supported by the National Natural Science Foundation of China (Grant Nos.61574171,61704127,11875229,51872251,and 12027813)。
文摘The single event effect(SEE) sensitivity of silicon–germanium heterojunction bipolar transistor(Si Ge HBT) irradiated by 100-Me V proton is investigated. The simulation results indicate that the most sensitive position of the Si Ge HBT device is the emitter center, where the protons pass through the larger collector-substrate(CS) junction. Furthermore, in this work the experimental studies are also carried out by using 100-Me V proton. In order to consider the influence of temperature on SEE, both simulation and experiment are conducted at a temperature of 93 K. At a cryogenic temperature, the carrier mobility increases, which leads to higher transient current peaks, but the duration of the current decreases significantly.Notably, at the same proton flux, there is only one single event transient(SET) that occurs at 93 K. Thus, the radiation hard ability of the device increases at cryogenic temperatures. The simulation results are found to be qualitatively consistent with the experimental results of 100-Me V protons. To further evaluate the tolerance of the device, the influence of proton on Si Ge HBT after gamma-ray(^(60)Coγ) irradiation is investigated. As a result, as the cumulative dose increases, the introduction of traps results in a significant reduction in both the peak value and duration of the transient currents.
