Towards thinner and low bowing silicon solar cells: form the boron and aluminum co‐doped back surface field with thinner metallization film

Using thinner wafers can largely reduce the cost of silicon solar cells. One obstacle of using thinner wafers is that few methods can provide good dopant concentration for the back surface field (BSF) and good ohmic contact while generated only in low bowing. In this paper, we have demonstrated the screening–printing B and Al (B/Al) mixture metallization film technique, making use of the screen‐printing technique and the higher solubility of B in silicon to form a B/Al‐BSF. This technique can raise the carrier concentration in the BSF by more than one order of magnitude and reduce the back surface recombination at a low firing temperature (≤800 °C). We have also shown that through the new technique, the metallization paste thickness at the rear could be reduced largely, which however did not degrade the solar cell efficiency. All these efforts are aiming for pushing forward the application of thinner wafers. Copyright © 2011 John Wiley & Sons, Ltd.     

Boosting the Charge Transport Property of Indeno[1,2‐b]fluorene‐6,12‐dione though Incorporation of Sulfur‐ or Nitrogen‐Linked Side Chains

Alkyl chains are basic units in the design of organic semiconductors for purposes of enhancing solubility, tuning electronic energy levels, and tailoring molecular packing. This work demonstrates that the carrier mobilities of indeno[1,2‐b ]fluorene‐6,12‐dione ( IFD )‐based semiconductors can be dramatically enhanced by the incorporation of sulfur‐ or nitrogen‐linked side chains. Three IFD derivatives possessing butyl, butylthio, and dibutylamino substituents are synthesized, and their organic field‐effect transistors (OFET) are fabricated and characterized. The IFD possessing butyl substituents exhibits a very poor charge transport property with mobility lower than 10^?7 cm² V^?1 s^?1. In contrast, the hole mobility is dramatically increased to 1.03 cm² V^?1 s^?1 by replacing the butyl units with dibutylamino groups ( DBA‐IFD ), while the butylthio‐modified IFD ( BT‐IFD ) derivative exhibits a high and balanced ambipolar charge transport property with the maximum hole and electron mobilities up to 0.71 and 0.65 cm² V^?1 s^?1, respectively. Moreover, the complementary metal–oxide–semiconductor‐like inverters incorporated with the ambipolar OFETs shows sharp inversions with a maximum gain value up to 173. This work reveals that modification of the aromatic core with heteroatom‐linked side chains, such as alkylthio or dialkylamino, can be an efficient strategy for the design of high‐performance organic semiconductors.     

基于博弈论的无线自组网路由协议研究

Ad hoc网络,是无线自组织网络的简称.它没有固定的基础设施,网路中的每个节点具有双重身份,即通信终端和路由器.路由协议是Ad hoc网络的关键技术,但传统的协议在设计时并未考虑效率因素.本文基于博弈论提出一种平均场均衡的方法,能有效的减少信息泛洪,以满足节点移动性对自组网的性能要求.     

强电场对NiO电子结构性质的影响研究

基于平面波密度泛函理论研究了电场强度为10V?nm-1下立方结构氧化镍的电子结构性质。结果表明:立方相氧化镍在电场强度10V?nm-1下呈现导体的能带结构,价带上移到导带,态密度谱图在多个能量取得最值,局域化效应增强,费米能级附近的态密度增大为原系统的2倍多。费米能级上的载流子浓度由4 e/eV增大到15 e/eV,这源于Op、Nis、Nid态对费米面的贡献。强电场下的电子在不同量子状态之间显示了明显的转移,介电函数计算表明强电场下体系在0.32 eV附近具有最大的吸收,吸收峰峰值66.89。强电场明显调控了NiO的电学、光学和场致光吸收性能。     

电磁场与电磁波教学思考

“电磁场与电磁波”课程是电子科学与技术、通信工程、电子信息等专业的一门重要的专业基础课程。该课程具有内容多、涉及面广、理论性强、概念抽象、涉及数学概念多等特点,是有一定教学难度的课程。本文针对这些特点,从内容安排、形式设计多个角度展开探讨,认为通过细致的课堂教学安排,充分利用各类资源可以达到更好的教学效果。     

Various density light field image coding based on distortion minimization interpolation

In recent years, the light field (LF) as a new imaging modality has attracted wide interest. The large data volume of LF images poses great challenge to LF image coding, and the LF images captured by different devices show significant differences in angular domain. In this paper we propose a view prediction framework to handle LF image coding with various sampling density. All LF images are represented as view arrays. We first partition the views into reference view (RV) set and intermediate view (IV) set. The RVs are rearranged into a pseudo sequence and directly compressed by a video encoder. Other views are then predicted by the RVs. To exploit the four dimensional signal structure, we propose the linear approximation prior (LAP) to reveal the correlation among LF views and efficiently remove the LF data redundancy. Based on the LAP, a distortion minimization interpolation (DMI) method is used to predict IVs. To robustly handle the LF images with different sampling density, we propose an Iteratively Updating depth image based rendering (IU-DIBR) method to extend our DMI. Some auxiliary views are generated to cover the target region and then the DMI calculates reconstruction coefficients for the IVs. Different view partition patterns are also explored. Extensive experiments on different types LF images also valid the efficiency of the proposed method.     

基于磁场检测的自平衡巡线智能小车设计

文中以第七届"飞思卡尔"杯大学生智能车竞赛为背景,以飞思卡尔MC9S12XS128单片机为核心,设计了一种自平衡巡线智能车系统。本设计基于倒立摆的动力学模型,经过卡尔曼滤波算法对陀螺仪和加速度计的输出信号进行处理得到智能车的角速度和倾角,再通过PID运算处理后的输出控制智能车的平衡、前进和转向。实验及实际比赛表明,本智能车系统可稳定运行,具有速度快,转向灵活,抗干扰性强的特点。     

“电磁场理论”课程教学网站的设计与功能

本文主要介绍我校电磁场理论教学网站的设计及其在课程教学中的作用。笔者分析了该教学网站的设计需求,给出了其设计思想,介绍了该教学网站的静态模块和动态模块的具体功能。我校电磁场理论教学网站的设计为＂电磁场理论＂课程的网络教学提供了平台,对＂电磁场理论＂课程教学的促进作用已初见成效。     

SDI音频解嵌IP模块设计及应用

针对串行数字接口（SDI）,提出了一种基于FPGA的音频数据IP模块解嵌方案。介绍了相关协议标准,重点介绍了音频解嵌IP模块的内核架构与设计过程,并给出了一个基于本IP模块的SDI音频解嵌系统应用实例。实践证明基于本IP模块的音频数据解嵌方案能有效地从SDI数据流中解嵌出音频数据,实现音、视频同步;并且本IP模块具有很强的通用性和可移植性,能提高设计效率,降低产品成本。     

基于FPGA实现RS(255,239)编码器

论文研究了RS码的原理和编码器结构,分析讨论了有限域上的乘、加运算及其实现方法,在此基础上基于FPGA设计了RS(255,239)编码器,并用ALTERA公司的FPGA芯片进行了实现,最后给出了结果分析。文章对基于FPGA的纠错码设计有重要意义。