All‐Solution‐Processed Random Si Nanopyramids for Excellent Light Trapping in Ultrathin Solar Cells

Si nanopyramids have been suggested as one of the most promising Si nanostructures to realize high‐efficient ultrathin solar cells or photodetectors due to their low surface area enhancement and outstanding ability to enhance light absorption. However, the present techniques to fabricate Si nanopyramids are either complex or expensive. In parallel, disordered nanostructures are believed to be extremely effective to realize broadband light trapping for solar cells. Here, a simple and cost‐effective method is presented to form random Si nanopyramids based on an all‐solution process, the mechanism behind which is the successful transfer of the generation site of bubbles from Si surface to the introduced Ag nanoparticles so that OH^? can react with the entire Si surface to naturally form random and dense Si nucleus. For optical performance, it is experimentally demonstrated that the random Si nanopyramid textured ultrathin crystalline Si (c‐Si) can achieve light trapping approaching the Lambertian limit. Importantly, it is revealed, by numerical calculations, that random Si nanopyramids outperform periodic ones on broadband light absorption due to more excited optical resonance modes. The finding provides a new opportunity to improve the performance of ultrathin c‐Si solar cells with a simpler process and lower cost.     

基于灰色层次分析法的战场电磁环境效应评估

现代战场电磁环境日趋复杂化,有效地评估战场电磁环境效应非常必要。首先,简要分析了战场电磁问题的几种常用研究方法,并指出了其各自不足;其次,依照钱学森的系统科学思想和从定性到定量的综合集成方法论,研究了基于灰色层次分析法的战场电磁环境效应评估,其评估建模步骤为:采用层次分析法建模战场电磁环境效应评估体系、依照广义专家系统确定指标权重、应用灰色理论获取综合评价结论;最后,选定某特定战场电磁环境,采用灰色层次分析法进行了电磁环境效应的评估计算,仿真结果验证了该方法的有效性,同时也表明了应用综合集成方法解决电磁领域问题的可行性。     

适用无源射频识别标签的集成压力传感器设计

针对无源射频识别 (RFID) 传感器标签发展的需求,采用商业化互补金属氧化物 (CMOS) 工艺,设计了一种集成电容式压力传感器及其接口电路。集成压力传感器采用金属层M1作为下电极,牺牲的金属层M2作为间隙层,通过过孔连接的金属层M3和M4及其介质构成上电极。传感器接口电路基于锁相环原理,采用全数字结构,将传感器信号转移到频率域处理。后期测试结果显示,所设计的压力传感器线性度高,温度稳定性好,接口电路在1 V电源电压下,只消耗了0.6 μW功率,尤其适用于无源RFID标签的设计。     

3D holoscopic image coding scheme using HEVC with Gaussian process regression

3D holoscopic image, also known as integral imaging, light field imaging and plenoptic imaging, can provide a natural and fatigue-free 3D visualization. However, a large amount of data is required to represent the 3D holoscopic content. Therefore, efficient coding schemes for such particular type of image are needed. In this paper, we propose a Gaussian process regression based prediction scheme to compress the 3D holoscopic image. In the proposed scheme, the coding block and its prediction supports are modeled as a Gaussian process (GP) and Gaussian process regression (GPR) is used to obtain a better prediction of the coding block. Limited searching windows in horizontal and vertical directions are used to obtain the prediction supports, and a filtration method is designed to judge the reliability of the obtained prediction supports. Moreover, in order to alleviate the high complexity caused by GPR, a sparsification method is also put forward. Experimental results demonstrate the advantage of the proposed scheme for 3D holoscopic image coding in terms of different quality metrics as well as the visual quality of the views rendered from decompressed 3D holoscopic content, compared to the HEVC intra-prediction method and several other prediction methods in this field.     

Structural,optical and transport properties of SxZnO

In this paper, S-doped ZnO (S_xZnO) was prepared using sol-gel method at different S amounts. The structural, optical and transport properties were investigated. The introduction of S atoms into the ZnO network was found to lower the crystallization level which results in reducing the crystallite size up to x=0.3. The doping process is confirmed by the observed peak at ~610 cm⁻¹ in the ATR spectrum related to the Zn-S linking. EDX mapping shows a homogeneous distribution of S atoms on the particles surface. The best compromise between the band gap (Eg=2.96 eV), the charge carriers (N_A=2.139×10²² cm⁻³), the conductivity (σ=5.56×10⁻⁴ Ω⁻¹ m⁻¹) and the mobility (µ=16.26×10⁻¹⁴ m² V⁻¹ s⁻¹) is obtained for x=0.1. The conduction mechanism is assumed by small hopping polaron. The S-doping has impacted positively the photocatalytic activity of ZnO, with particularly high performance for S_0.2ZnO.     

Stable resistive switching characteristics of Ce:HfOx film induced by annealing process

In this work, Ce:HfO_x films were fabricated and the resistive switching characteristics were investigated. The chemical bonding states of the films were explored by X-ray photoelectron spectroscopy. The annealing process was carried out to modulate the concentration of oxygen vacancies in the film to confirm the dominant role of oxygen vacancies on resistive switching behaviors, which resulted in the elimination of unstable oxygen vacancies and the introduction of oxygen vacancy near Ce dopants due to the reduction of Ce⁴⁺. Benefiting from the oxygen vacancies near Ce dopants, stable resistive switching performance can be achieved for the annealed Ce:HfO_x sample. A schematic diagram based on the formation and rupture of oxygen vacancy filaments was proposed to illustrate the switching behaviors of annealed Ce:HfO_x sample.     

干涉仪测向技术现状与发展研究

从解模糊和天线排列形式、鉴相技术、通道幅相不一致校正方法和接收数据处理方式四个方面论述了干涉仪测向技术的现状和发展趋势。对每一方面现存的不同实现方法的主要原理和优劣性做了详细说明和比较,探讨了下一步的发展和改进思路。为干涉仪测向装备在特定条件下应用技术的选择提供理论依据,为新装备的研制提供参考意见。     

Design and application of a depletion-mode NJFET in a high-voltage BiCMOS process

A novel depletion-mode NJFET compatible high-voltage BiCMOS process is proposed and experimentally demonstrated with a four-branch 12-bit DAC(digital-to-analog converter).With this process,an NJFET with a pinch-off voltage ofabout-1.5 V and a breakdown voltage of about 16 V,an NLDDMOS(N-type lightly-dosed-drain in MOS) with a turn-on voltage of about 1.0 V and a breakdown voltage of about 35 V,and a Zener diode with a reverse voltage of about 5.6 V were obtained.Measurement results showed that the conver...     

Process optimization of a deep trench isolation structure for high voltage SOI devices

The process reasons for weak point formation of the deep trench on SOI wafers have been analyzed in detail.An optimized trench process is also proposed.It is found that there are two main reasons:one is over-etching laterally of the silicon on the surface of the buried oxide caused by a fringe effect;and the other is the slow growth rate of the isolation oxide in the concave silicon corner of the trench bottom.In order to improve the isolation performance of the deep trench,two feasible ways for optimizi...     

自动动态补偿功能改善酸蚀蚀刻不均匀性问题

在酸蚀制程中,由于其蚀铜量较大,蚀刻线生产时蚀刻速度较慢,导致蚀刻不均匀性对线路制作存在很大影响,为改善蚀刻不均匀性的问题,采用奥宝公司专门开发的可制造性设计功能----自动动态补偿(Dynamic Etch Compensation),根据不同的间距设置不同的线宽补偿量,来确保蚀刻后线宽的一致性。