22 nm工艺超薄体全耗尽绝缘体上硅晶体管单粒子瞬态效应研究

利用计算机辅助设计技术数值仿真工具, 研究22 nm工艺技术节点下超薄体全耗尽绝缘体上硅晶体管单粒子瞬态效应, 系统地分析了掺杂地平面技术、重离子入射位置、栅功函数和衬底偏置电压对于单粒子瞬态效应的影响. 模拟结果表明, 掺杂地平面和量子效应对于单粒子瞬态效应影响很小, 重离子入射产生大量电荷, 屏蔽了初始电荷分布的差异性. 单粒子瞬态效应以及收集电荷和重离子入射位置强相关, 超薄体全耗尽绝缘体上硅最敏感的区域靠近漏端. 当栅功函数从4.3 eV变化到4.65 eV时, 单粒子瞬态电流峰值从564 μA减小到509 μA, 收集电荷从4.57 fC减小到3.97 fC. 超薄体全耗尽绝缘体上硅器件单粒子瞬态电流峰值被衬底偏置电压强烈调制, 但是收集电荷却与衬底偏置电压弱相关. 关键词： 超薄体全耗尽绝缘体上硅 单粒子瞬态效应 电荷收集 数值仿真     

Effect of aluminum co-doping on the formation of Yb2+ in Ytterbium-doped high silica glass

Yb3+ singly doped and Yb3+/Al3+ co-doped high silica glass samples are prepared,and their luminescent properties are investigated.Al3+ is considered as a beneficial activator for Yb3+-doped glass.However,the experimental result shows that the addition of Al3+ results in the transformation from Yb3+ to Yb2+ and the improvement in the photon luminescence of Yb2+.These characteristics indicate the role of Al3+ in Yb3+-doped glass.     

Resonantly pumped Q-switched Er:GdVO4 laser

We describe a Q-switched Er:GdVO₄ laser resonantly pumped by a MgO-doped periodically poled LiNbO₃ optical parametric oscillator （MgO: PPLN OPO） at 1536 nm. In continuous-wave lasing, the maximum output power is 1.14 W with an incident pump power of 4.7 W and a slope efficiency of 27%. In Q-switched operation, 1.1 mJ of output pulse energy is achieved at 200 Hz. The upper-state lifetime at different pulse repetition frequencies is also calculated.     

Fabrication of rhenium Josephson junctions

Rhenium is a superconductor with a relatively weak tendency to oxidize, which is advantageous in superconducting quantum circuit and qubit applications. In this work, Re/A1-A1Ox/Re Josephson tunnel junctions were fabricated using a selective film-etching process similar to that developed in Nb trilayer technology. The Re films had a superconducting transition temperature of 4.8 K and a transition width of 0.2 K. The junctions were found to be highly reproducible using the fabrication process and their characteristics had good quality with a low leakage current and showed a superconducting gap of 0.55 meV.     

Octagonal dual-concentric-core photonic crystal fiber for C-band dispersion compensation with low confinement loss

A novel kind of octagonal dual-concentric-core photonic crystal fiber （PCF） is calculated with the finite element method （FEM） and proposed for broadband compensation. In order to realize highly negative dispersion, the hole diameter of the second ring is reduced relative to conventional PCFs. Numerical simulation results show that when the diameters of large holes and small holes are 0.77 pm and 0.5 #m, respectively, and the pitch of the adjacent rings is 1.1 μm, the negative dispersion can achieve about 840 ps.nm^-1.km^-1 at 1 550 nm and the dispersion slope can match with single mode fiber （SMF-28） perfectly. This PCF can compensate the positive dispersion and also its slope of about 50 times its length of SMF-28 fiber, which is suitable for C-band optical fiber telecommunication as a dispersion compensation fiber.     

Research on lenses assemble precision in complicate laser amplification system

In a certain amplification system, signal laser can be amplified from 1 nJ to 5 J. To realize a high quality imaging transfer, meet beam diameter expansion requirement, and get good filtering effects, three spatial filters are designed and assembled. Lenses in these spatial filters can be assembled and adjusted by their reflection spots to meet wave-front requirements. In this letter, we analyze precision of the assembling, and make a ray-tracing simulation to discuss the relation between assembling precision and lenses parameters. On the optimized distance of 1000 mm, adjusting precision of lens tilt can reach 5 mrad.     

Null testing toroidal surface and biconic surface with cylinder compensator

Toroidal surface and biconic surface are employed increasingly, however their profile cannot be null tested easily for they are non-rotationally symmetrical. Null testing method with cylinder compensator is proposed to solve this problem. The theory of this method is revealed. The errors of this method are present. Three typical testing optical systems with cylinder compensator are demonstrated at last. The design results and total error indicate that this method is feasible.     

Charge state effect on the K-shell ionization of iron by xenon ions near the Bohr velocity

Fe K-shell ionization cross sections induced by 2.4–6.0 MeV Xe20+are measured and compared with different binaryencounter-approximation(BEA)models.The results indicate that the BEA model corrected both by the Coulomb repulsion and by the effective nuclear charge(Zeff)agrees well with the experimental data.Comparison of Fe K-shell X-ray emission induced by 5 MeV xenon ions with different initial charge states(20+,22+,26+,30+)verifies the applicability of the effective nuclear charge(Zeff)correction for the BEA model.It is found that Zeffcorrection is reasonable to describe direct ionization induced by xenon ions with no initial M-shell vacancies.However,when the M shell is opened,the Zeffcorrected BEA model is unable to explain the inner-shell ionization,and the electron transfer by molecular-orbital promotion should be considered.     

Tm3+,Yb3+共掺钨酸钙多晶材料的上转换发光及荧光温度特性

采用高温固相法制备了Tm³⁺,Yb³共掺CaWO₄多晶材料. 980 nm二极管激光器激发下,在可见区获得了¹G₄→³H₆,¹G₄→³H₄,³H₂,³H₃→³H₆ 跃迁产生的上转换荧光. 讨论了Yb³⁺ 离子浓度的变化对Tm³⁺ 的上转换发光强度的影响,同时根据荧光强度比的方法研究了689 和705 nm 红色上转换荧光在313–773 K 范围内的温度特性. 结果表明：基于Tm³⁺,Yb³⁺ 共掺CaWO₄ 多晶材料的红色上转换荧光可以实现温度监测,其测温的最大灵敏度值为5.7×10^-4 K^-1,相应的测量温度为458 K. 关键词： 上转换发光 3+')" href="#">Tm³⁺ 钨酸钙 荧光温度传感     

非晶硅界面缓冲层对非晶硅锗电池性能的影响

针对非晶硅锗电池本征层高锗含量时界面带隙失配以及高界面缺陷密度造成电池开路电压和填充因子下降的问题,通过在PI界面插入具有合适带隙的非晶硅缓冲层,不仅有效缓和了带隙失配,降低界面复合,同时也通过降低界面缺陷密度改善内建电场分布,从而提高了电池的收集效率. 进一步引入IN界面缓冲层以及对非晶硅锗本征层进行能带梯度设计,在仅采用Al背电极时,单结非晶硅锗电池转换效率达8.72%. 关键词： 非晶硅缓冲层 非晶硅锗薄膜太阳电池 带隙 界面