Chalcogenide Glasses Based on Germanium Disulfide for Second Harmonic Generation

High second‐order susceptibilities are created by thermal poling in bulk germanium disulfide based chalcogenide glasses. Experimental conditions of the poling treatment (temperature, voltage, time) were optimized for each glass composition. The second‐order nonlinear signals were recorded by using the Maker fringes experiment and a second‐order coefficient χ⁽²⁾ up to 8 pm V^–1 was measured in the Ge₂₅Sb₁₀S₆₅ glass. This value is obtained using a simulation based on accurate knowledge of the thickness of the nonlinear layer. Two mechanisms are proposed to explain the creation of a nonlinear layer under the anode: the formation and the migration of charged defects towards the anode may mainly occur in Ge₂₀Ga₅Sb₁₀S₆₅ and Ge₂₅Ga₅S₇₀ glasses, whereas the migration of Na⁺ ions towards the cathode may be responsible for the accumulation of negative charges under the anode in Ge₃₃S₆₇ and Ge₂₅Sb₁₀S₆₅ glasses. Different electronic conductivity behaviors seem to be at the origin of the phenomenon. In parallel, the potential effect of the poling treatment on the structural and electronic properties is studied using Raman spectroscopy and secondary ion mass spectroscopy measurements.     

低质量Si材料制备太阳电池

通过对比不同硼-磷(B-P)补偿程度的低成本、高杂质含量硅材料制备的太阳电池的性能,发现在含B和其它杂质含量都比较高的Si材料中通过掺入P补偿过多的B可以提高低质量Si片的电阻率、增加少数载流子寿命从而提高电池效率同时还能够减少电池性能的衰减.利用低质量Si材料(B含量2*10-6wt)制作出了效率达到14%左右的大面...     

Electromodulation and magnetomodulation of exciton dissociation in electron donor (starburst amine) : electron acceptor (bathocuproine) system

Electric field dependencies of electromodulated photoluminescence and photocurrents as well as the magnetic field effects on photocurrents, photovoltaic characteristics, electromodulated photoluminescence and photoluminescence have been investigated in vacuum evaporated films of m-MTDATA:BCP (4,4′,4″-tris(N-(3-methylphenyl)-N-phenylamino)triphenylamine and bathocuproine) system. The electromodulation processes do remain in accordance with Onsager as well as with the Sano–Tachiya–Noolandi–Hong formalisms of electron–hole pair separation. While the electromodulated photocurrents are due to operation of both long-radius and short-radius e–h pairs, the electromodulated photoluminescence quenching is related to merely short-radius fraction of the e–h pairs involved in the exciplex creation process. The photocurrents, photovoltaic characteristics, photoluminescence and electromodulated photoluminescence are influenced by external magnetic field of the hyperfine coupling (HFC) scale which modulates the singlet–triplet intersystem crossing of long-radius e–h pairs.     

适合低功耗工作的MOS电荷泵

提出了两种适合在低功耗条件下工作的电荷泵电路,预充电电荷泵采用预充电机制提高了电荷泵的工作效率;而Domino电荷泵则采用内部电路控制电荷泵充电电容的充放电,不仅降低了功耗,同时均化了瞬态功耗.这解决了电荷泵在充电期间功耗过大的问题,使它们不仅能适用于有较强电源的电路,也可以在无源或低功耗的环境下工作.     

Parasitic emission in inkjet-printed InP-based quantum dot light-emitting diodes

Indium phosphide-based colloidal quantum dot (QD) light-emitting diodes represent a promising technology for various lighting applications. To promote this innovative technology closer to an industrialized production environment, the fabrication methods should be adapted. Hence it is necessary to replace the common spin-coating process under an inert atmosphere, by a more cost-efficient inkjet-printing process at ambient conditions. However, in our case, this transfer results in devices with limited performance and parasitic emission channels besides the desired QD emission. In this paper, we identify the physical origin of these parasitic emission channels for three different device layouts depending on the QD material as well as the number of inkjet-printed layers. For the first type of devices, a recombination process on the dopant of the electron transporting layer (ETL) as well as an exciplex formation at the interface between QDs and ETL was identified. For the next device layout, the introduction of a hole-conducting matrix embedding the QDs leads to a shift of the parasitic emission with contributions from the matrix material. Finally, the integration of a hole injection layer leads to a reduction of the undesired emission processes. For all three kinds of devices, the spacial separation of the dopant in the ETL from the QDs is a critical factor, since it directly influences the parasitic emission channels.     

改进的混合MAP-POCS超分辨率图像复原算法研究

超分辨率图像复原技术在不改变硬件的条件下可提高成像系统获取图像的分辨率。研究了图像退化机理,建立了精确的图像退化过程模型,提出一种改进的混合MAP-POCS复原算法,将POCS的凸集约束条件加入到MAP估计过程中。运用峰值信噪比(PSNR)等评价手段对复原图像进行质量评价。仿真结果表明,改进的混合复原算法能够有效地保证复原求解的收敛性并保持复原图像的边缘细节,提升了超分辨率的复原效果。     

一种镍基单晶高温合金中碳化物热稳定性研究

利用SEM、TEM研究了一种镍基单晶高温合金中碳化物在950℃时效不同时间的退化规律。固溶处理过程中形成的MC碳化物随时效时间的增加而逐渐退化为M6 C和M23 C6碳化物。同时,由于在时效处理过程中Re元素进入M6 C碳化物中,破坏了其结构稳定性,促使M6 C碳化物也可以退化为M23 C6碳化物。至时效3000 h时,没有观察到碳化物退化的逆反应。本研究可以为高温合金高温下服役的稳定性提供实验参考。     

大功率脉冲调制管的设计

叙述了脉冲调制器对调制管的要求,研究了阳栅之间空间电荷效应对调制管阳极特性的影响,提出了满足调制器要求的脉冲调制管的新的设计思想。     

A very-high output impedance charge pump for low-voltage low-power PLLs

This article presents the design of a high output compliance, very-high output impedance single-ended charge pump implemented using a new low-voltage current mirror. The output current is sampled and a feedback loop forces it to be equal to the desired reference current. This results in a very-high output impedance over a very wide output voltage range, accurate Up/Down current matching, and low transient glitches. The proposed charge pump was implemented using STMicroelectronics 1-V 90-nm CMOS process. Simulations using Spectre show that the Up/Down output currents remain constant and matched within 1% over a charge pump output voltage ranging from 119 to 873 mV. Monte Carlo process variations and mismatch simulations indicate that the 1-σ standard deviation between the Up and Down current components is , or 6.8% of the nominal charge pump current at either end of the output voltage range.     

内容计费包月模块平衡性统计的优化及应用

基于内容计费包月业务计费流程,论文分析了平衡性分析过程中缺乏自动化的统计分析工具、缺乏全流程的异常监控和告警等相关问题,从系统统计、异常监控等方面提出了一些优化措施。通过固化全流程各环节相关统计程序,增加话单及费用异常波动等监控和告警,实现了自动化数据统计与展示,提升了系统平衡性统计分析能力,有利于及时发现内容计费包月业务的异常情况。