Influence of different oxidants on the band alignment of HfO2 films deposited by atomic layer deposition

Based on X-ray photoelectron spectroscopy （XPS）, influences of different oxidants on band alignment of HfO2 films deposited by atomic layer deposition （ALD） are investigated in this paper. The measured valence band offset （VBO） value for H2O-based HfO2 increases from 3.17 eV to 3.32 eV after annealing, whereas the VBO value for O3-based HfO2 decreases from 3.57 eV to 3.46 eV. The research results indicate that the silicate layer changes in different ways for H2O-based and O3-based HfO2 films after the annealing process, which plays a key role in generating the internal electric field formed by the dipoles. The variations of the dipoles at the interface between the HfO2 and SiO2 after annealing may lewd the VBO values of H2O-based and O3-based HfO2 to vary in different ways, which fits with the variation of fiat band （VFB） voltage.     

Influence of different oxidants on the band alignment of HfO₂ films deposited by atomic layer deposition

Based on X-ray photoelectron spectroscopy(XPS),influences of different oxidants on band alignment of HfO2 films deposited by atomic layer deposition(ALD) are investigated in this paper.The measured valence band offset(VBO) value for H2 O-based HfO2 increases from 3.17 eV to 3.32 eV after annealing,whereas the VBO value for O 3-based HfO2 decreases from 3.57 eV to 3.46 eV.The research results indicate that the silicate layer changes in different ways for H2 O-based and O3-based HfO2 films after the annealing process,which plays a key role in generating the internal electric field formed by the dipoles.The variations of the dipoles at the interface between the HfO2 and SiO2 after annealing may lead the VBO values of H2 O-based and O 3-based HfO2 to vary in different ways,which fits with the variation of flat band(VFB) voltage.     

国产星用VDMOS器件总剂量辐射损伤效应研究

研究了两种国产星用VDMOS器件在不同偏置条件下的总剂量辐射损伤效应, 探讨了器件的阈值电压、击穿电压、导通电阻、漏电流等电参数随累积剂量、退火时间的变化关系. 实验结果表明这两种国产星用VDMOS器件辐照后电参数符合技术指标, 满足在复杂空间电离辐射环境下工作的要求.此外, 通过对器件在不同偏置条件下的总剂量辐射损伤效应进行研究, 对其他型号星用VDMOS器件工艺和设计的进一步改进, 具有参考作用.     

极化效应对AlGaN/GaN异质结p-i-n光探测器的影响

基于等效薄层电荷近似模拟表征极化电荷的作用, 通过自洽求解Poisson-Schrödinger方程以及求解载流子连续性方程, 计算并且讨论了p-AlGaN层掺杂浓度和界面极化电荷对AlGaN/GaN异质结p-i-n紫外探测器能带结构和电场分布以及光电响应的影响. 结果表明, 极化效应与p-AlGaN层掺杂浓度相互作用对探测器性能有较大影响. 其中, 在完全极化条件下, p-AlGaN层掺杂浓度越大, p-AlGaN层的耗尽区越窄, i-GaN层越容易被耗尽, 器件光电流越小. 在一定掺杂浓度条件下, 极化效应越强, p-AlGaN层的耗尽区越宽, 器件的光电流越大. 最后还分析了该结构在不同温度下的探测性能, 证明了该结构可以在高温下正常工作.     

5-取代吲哚-2-酮的合成

4-取代苯胺依次与水合氯醛及盐酸羟胺反应制得4-取代异亚硝基乙酰苯胺(2a～2e);2在浓硫酸作用下环合制得5-取代靛红(3a～3e);3通过改进的Wolff-Kishner-黄鸣龙反应合成了重要的药物中间体——5-取代吲哚-2-酮(5a～5e);5a通过硝化制得5-硝基吲哚-2-酮(5f);5f被还原制得5-氨基吲哚-2-酮(5g)。其结构经1H NMR和MS确证。     

四苯乙烯衍生物的合成、性能及其对铀酰离子的荧光识别

聚集诱导发光(AIE)效应在铀酰离子痕量检测方面具有广阔的应用前景。本文以四苯乙烯(TPE)为母体,设计合成了一种TPE席夫碱类化合物T2,并对其溶液态和聚集态的光学性质进行了表征。结果表明,T2具有AIE特性。并且,当向T2中加入铀酰离子后,体系荧光发射峰从540nm蓝移到500nm,肉眼可见由黄色到黄绿色的明显颜色变化,表明化合物T2可用于检测水体中的铀酰离子。     

Magnetic properties and magnetic entropy changes of La1-xPrxFe11.5Si1.5 compounds with 0≤x≤ 0.5

Magnetic properties and magnetic entropy changes in LaFe$_{11.5}$Si$_{1.5}$ have been investigated by partially substituting Pr by La. It is found that La$_{1 - x}$Pr$_{x}$Fe$_{11.5}$Si$_{1.5}$ compounds remain cubic NaZn$_{13}$-type structures even when the Pr content is increased to 0.5, i.e. $x = 0.5$. Substitution of Pr for La leads to a reduction in both the crystal constant and the Curie temperature. A stepwise magnetic behaviour in the isothermal magnetization curves is observed, indicating that the characteristic of the itinerant electron metamagnetic (IEM) transition above $T_{\rm C}$ becomes more prominent with the Pr content increasing. As a result, the magnetic entropy change is remarkably enhanced from 23.0 to 29.4\,J/kg$\cdot$K as the field changes from 0 to 5\,T, with the value of $x$ increasing from 0 to 0.5. It is more attractive that the magnetic entropy changes for all samples are shaped into high plateaus in a wide range of temperature, which is highly favourable for Ericsson-type magnetic refrigeration.     

Spatio-spectral dynamics of soliton pulsation with breathing behavior in the anomalous dispersion fiber laser

We have numerically and experimentally observed the soliton pulsation with obvious breathing behavior in the anomalous fiber laser mode-locked by a nonlinear polarization rotation technique. The numerical study of the soliton pulsation with breathing behavior was analyzed through the split-step Fourier method at first, and it was found that the phase difference caused by the polarization controller would affect the breathing characteristics. Then, taking advantage of the dispersive Fourier transform technique, we confirmed the breathing characteristic of soliton pulsation in the same fiber laser as the simulation model experimentally. These results complement the research on the breathing characteristic of soliton pulsation.     

类普鲁士蓝为前驱体制备纳米NiO及其电化学电容行为

Nanosized nickel oxide was synthesized by immersing the precursor NiHCNFe into 1 mol·L^-1 KOH solution to obtain nickel hydroxide (Ni(OH)₂) and then annealing in air at 300 ℃. X-ray diffraction (XRD) and transmission electron microscopy (TEM) tests showed the prepared samples were rhombohedral crystalline structure of NiO with uniform grain and with a diameter of about 8 nm. Electrochemical properties of NiO were examined by cyclic voltammetry, ac impedance and galvanostatic charge-discharge tests. The results demonstrated that nickel oxide had a good capacitive behavior and cyclability due to its nanostructure. The highest specific capacitance of nickel oxide was about 303 F·g^-1 at a charge/discharge current density of 5 mA·cm^-2 in 6 mol·L^-1 KOH solution.     

基于红外反射光容积脉搏波的血管阻力研究

近红外光谱技术在血氧饱和度和血糖浓度的无损伤在体测量中得到了应用。本文利用基于反射式原理的红外光容积脉搏波对指尖和桡动脉进行了血管阻力等血流参数检测的研究。通过将提取到的光电容积脉搏波中峰峰值和特征K值参数与超声多普勒所测收缩期峰值血流速度和血管阻力参数进行相关性分析, 发现两者存在很强的相关性, 研究结果将扩展光电容积脉搏波在血流检测中的应用。