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101.
本文分别建立了含有本征SiGe层的SiGe HBT(异质结双极晶体管)集电结耗尽层各区域的电势、电场分布模型,并在此基础上,建立了集电结耗尽层宽度和延迟时间模型,对该模型进行了模拟仿真,定量地分析了SiGe HBT物理、电学参数对集电结耗尽层宽度和延迟时间的影响,随着基区掺杂浓度和集电结反偏电压的提高,集电结耗尽层延迟时间也随之增大,而随着集电区掺杂浓度的提高和基区Ge组分增加,集电结耗尽层延迟时间随之减小.
关键词:
SiGe HBT
集电结耗尽层
延迟时间 相似文献
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105.
采用密度泛函理论中的广义梯度近似(generalized gradient approximation, 简称GGA),对内掺氢分子富勒烯H2@C60及其二聚体的几何结构和电子结构进行了计算研究.发现无论是在H2@C60单体,还是在其二聚体中,氢倾向以分子形式存在于碳笼中心处,且在室温下氢分子可以做自由旋转.电子结构分析表明,氢分子掺入到C60和C120中,仅对距离费米能级以下-8eV至-5eV能级处有一定的贡献,其他能级的分布和能隙几乎没有变化. 相似文献
106.
潜艇的红外辐射特征是红外探测系统发现潜艇并进行跟踪的依据,研究潜艇红外特征模拟方法对潜艇探潜和修正对敌潜艇制导数据具有一定参考价值。从潜艇的外部环境出发,分析了影响水面航行潜艇红外特征的多种复杂因素,建立了传热模型,给出传热边界方程,模拟了潜艇表面红外特征,估算了探潜距离。 相似文献
107.
采用密度泛函理论PBE0方法,计算了单核配合物[Fe(CO)3(EtPhPpy)2] (1)、双核配合物[Fe(CO)3(EtPhPpy)2M(NCS)2] (2:M=Zn,3: M=Cd,4: M=Hg) 和[Fe(CO)3(EtPhPpy)2CdX2] (5:X=Cl,6: X=SCN)的几何构型和电子结构,研究了Fe-M相互作用及其对31P化学位移的影响. 结果表明:配合物的稳定性(S)为S(2)>S(3)>S(4),S(3)≈S(6)>S(5).在[Fe(CO)3(EtPhPpy)2CdX2]体系中,含[SCN]-配合物的稳定性大于含Cl-的. Fe-M相互作用的强度(I )顺序为I (2)≈I (3)相似文献
108.
The densest packing of tetrahedra is still an unsolved problem. Numerical simulations of random close packing of tetrahedra are carried out with a sphere assembly model and improved relaxation algorithm. The packing density and average contact number obtained for random close packing of regular tetrahedra is 0.6817 and 7.21 respectively, while the values of spheres are 0.6435 and 5.95. The simulation demonstrates that tetrahedra can be randomly packed denser than spheres. Random close packings of tetrahedra with a range of height are simulated as well. We find that the regular tetrahedron might be the optimal shape which gives the highest packing density of tetrahedra. 相似文献
109.
Shiyu Zhou Qiyan Zhang Deqiang Zhao Wenjuan Zong Zihong Fan Yaofang Sun Xuan Xu 《应用有机金属化学》2018,32(4)
Microspherical bismuth oxychloride (BiOCl) can only utilize ultraviolet (UV) light to promote photocatalytic reactions. To overcome this limitation, a uniform and thin BiOCl nanosheet was synthesized with a particle size of about 200 nm. As results of UV–visible diffuse reflectance spectroscopy showed, the band gap of this nanostructure was reduced to 2.78 eV, indicating that the BiOCl nanosheet could absorb and utilize visible light. Furthermore, the upconversion material NaYF4 doped with rare earth ions Yb3+ and Er3+ emitted visible light at 410 nm following excitation with near‐infrared (NIR) light (980 nm), which could be utilized by BiOCl to produce a photocatalytic reaction. To produce a high‐efficiency photocatalyst (NaYF4:Yb3+,Er3+@BiOCl), BiOCl‐loaded NaYF4:Yb3+,Er3+ was successfully synthesized via a simple two‐step hydrothermal method. The as‐synthesized material was confirmed using X‐ray diffraction, scanning electron microscopy, X‐ray photoelectron spectroscopy as well as other characterizations. The removal ratio of methylene blue by NaYF4:Yb3+,Er3+@BiOCl was much higher than that of BiOCl alone. Recycling experiments verified the stability of NaYF4:Yb3+,Er3+@BiOCl, which demonstrated excellent adsorption, strong visible‐light absorption and high electron–hole separation efficiency. Such properties are expected to be useful in practical applications, and a further understanding of the NIR‐light‐responsive photocatalytic mechanism of this new catalytic material would be conducive to improving its structural design and function. 相似文献
110.
Zhengluo Wang Zhiwei Zhao Yanru Zhang Dr. Xiaopeng Yang Xuan Sun Dr. Jinyang Zhang Prof. Linrui Hou Prof. Changzhou Yuan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(3):863-873
The exploration of anode materials with a high degree of electrochemical utilization for Li-ion batteries (LIBs) still remains a huge challenge despite pioneering breakthroughs. Rational engineering of electrode structures/components by facile strategies would offer infinite possibilities for the development of LIBs. In this study, one-dimensional ultralong nanohybrids of ultrafine NiCoO2 nanoparticles dispersed in situ in and/or on the surface of amorphous N-doped carbon nanofibers (NCO@ANCNFs) were fabricated by a bottom-up electrospinning protocol. By virtue of synergistic structural/component features, the obtained ultralong NCO@ANCNFs with low NCO loading (≈33.6 wt %) show highly efficient Li+ storage performance with high reversible capacity, high rate capability, and long cycle life. The unusual reversible crystalline transformation during cycling was analyzed. Quantitative analysis revealed that the pseudocapacitive contribution mainly accounts for the superior lithium storage of the NCO@ANCNFs. Besides, the ability of the hybrid anode to deliver competitive Li-storage properties even without conductive carbon greatly enhances its commercial applicability. An NCO@ANCNFs//LiNi0.8Co0.15Al0.05O2 full battery was assembled and exhibited striking electrochemical properties. This contribution offers a scalable methodology to fabricate highly efficient hybrid anodes for advanced next-generation LIBs. 相似文献