室内毫米波宽带移动接入及其误码性能

给出了室内MMW高速数据传输实验系统的基本框架结构;仿真了AWGN下系统未采用信道纠错编码和采用Punctured卷积编译码,子载波采用DQPSK和16DAPSK调制的OFDM系统平均误比特率(BER)性能,并给出了实验测试结果。     

量子阱太阳能电池的外量子效率

通过实验比较了砷化镓量子阱太阳能电池与不含量子阱结构的普通砷化镓太阳能电池的外量子效率.结果表明,量子阱太阳能电池吸收光子的波长从870nm扩展到了1000nm.当波长小于680nm时,量子阱太阳能电池的外量子效率低于普通太阳能电池;而当波长大于于680nm时,量子阱太阳能电池的外量子效率高于普通太阳能电池.对这个现象给出了解释,并对用量子阱太阳能电池代替三结电池的中间子电池的可能性进行了讨论.     

量子阱太阳能电池的外量子效率

通过实验比较了砷化镓量子阱太阳能电池与不含量子阱结构的普通砷化镓太阳能电池的外量子效率. 结果表明,量子阱太阳能电池吸收光子的波长从870nm 扩展到了1000nm. 当波长小于680nm时,量子阱太阳能电池的外量子效率低于普通太阳能电池;而当波长大于于680nm时,量子阱太阳能电池的外量子效率高于普通太阳能电池. 对这个现象给出了解释,并对用量子阱太阳能电池代替三结电池的中间子电池的可能性进行了讨论.     

基于图像处理的低效率太阳能电池片自动检测

太阳能作为一种普遍均匀、清洁环保的绿色能源,具有较大的开发潜力。针对多晶硅太阳能电池片生产加工过程中存在的各种缺陷,尤其是低效率(黑心)片对太阳能电池片能效的影响,文中研究了一种基于图像处理的低效率太阳能电池片自动检测方法。首先对多晶硅太阳能电池片的相关概念以及低效率(黑心)片产生的原因做了分析,并在此基础上,对基于电致发光图像处理的自动检测方法进行了研究,给出了检测原理和检测系统结构,重点对图像处理技术进行了探讨,通过峰值二值化方法对电致发光图像灰度进行二值化处理,避免了给定阈值二值化处理的不足,同时给出了算法实现流程及实验结果。所设计的自动检测方法为实现低效率太阳能电池片检测提供了一定的理论基础。     

太阳能电池发电量实时监控系统

为了实时监控太阳能电池发电量,设计一种太阳能电池发电量实时监控系统,该系统利用单片机和霍尔电流传感器实时测量太阳能电池的输出电压、电流得到输出功率,然后经运算得到电量值送液晶显示器显示结果。实验表明：该系统测量误差小于3％．且低成本、低功耗,使其在离网光伏系统中应用广泛。     

代码方式文字广播差错控制系统的实验研究

本文阐述了 RS 码(Reed-solomon)差错控制方案的室内实验系统,并给出了初步的室内实验接收效果。文字广播代码传送方实施将画面中的文字,图形用与其对应的代码来传送,接受段则根据受到的代码从内部     

太阳能电池续流储能间歇式供电系统实验研究

基于持续收集能量、间歇式供电的目的。本文介绍了超级电容特性参数,给出了超级电容、太阳能电池的选择方法,设计了太阳能电池续流储能间歇式供电系统,通过实验验证了续流储能的可行性。     

太阳能电池最大功率点跟踪技术探讨

介绍了光伏发电系统太阳能电池的输出特性及最大功率点跟踪技术的基本原理.分析了多种常用的跟踪方法的优缺点.重点研究了二次插值法的最大功率点跟踪技术.并设计了一个系统,应用常规实验方法及二次插值法寻找太阳能电池的最大输出功率,试验结果表明二次插值法能快速寻找太阳能电池的最大输出功率.     

太阳能电池发电量实时监控系统

为了实时监控太阳能电池发电量,设计一种太阳能电池发电量实时监控系统,该系统利用单片机和霍尔电流传感器实时测量太阳能电池的输出电压、电流得到输出功率,然后经运算得到电量值送液晶显示器显示结果.实验表明:该系统测量误差小于3%,且低成本、低功耗.使其在离网光伏系统中应用广泛.     

太阳能光电池硫酸铅储能系统的研究

太阳能电池通过光伏效应,把太阳能转化为电能,它是一个典型的非线形元件。给出了太阳能电池的物理数学模型。蓄电池作为重要的储能装置。本文对常用的硫酸铅蓄电池原理及工作情况作了详细介绍,构建了太阳能充电实验电路,对蓄电池充电进行了实验。     

分光谱太阳能光电转换系统研究

单种类光电子器件的光电响应特性难以获得与太阳能全光谱匹配的高效率光电转换,突破其物理限制的努力方向是研制高转换效率的“第三代”分光谱多结电池。在本工作中,采用分光谱技术,将太阳光谱分成4个子光谱区,分别为400－630nm;630－800nm;800-900nm;900-1800nm;与这些子光谱区的范围相对应,分别采用能隙值与子光谱区相匹配的4个不同种类的具有较高光电转换效率的高性能单结光电器件,实现将太阳光高效率转换成电能。在太阳能电池辐照测试的0.5－6.0个SUN(AM1.5G)变化条件下,对多光谱组合的太阳能电池的光电转换效率进行了测试,获得了在2.8个SUN(AM1.5G)辐照条件下37.7％的实测光电转换效率。在此基础上,给出了利用单结电池组合制备高效率组合型分光谱太阳能光电转换系统的途径,具有较低成本和实际推广应用价值。     

Numerical analysis of J–V characteristics of a polymer solar cell

A numerical method to determine the cell parameters from the analysis of the J–V characteristics of a polymer solar cell is proposed. This method uses the equations given by the diode model, experimental data from the literature, and an adequate fitting procedure with seven fit parameters. Different aspects of the obtained results are discussed. Information concerning cell design optimization is also obtained. The method is of general application in the field of polymer solar cells, as well as to any kind of diode‐like cell. Copyright © 2010 John Wiley & Sons, Ltd.     

The effect of bias light on the spectral responsivity of organic solar cells

The spectral responsivity, S, and the related spectrally resolved photon-to-electron external quantum efficiency, EQE, are standard device characteristics of organic solar cells and can be used to determine the short-circuit current density and power conversion efficiency under standardized test conditions by integrating over the spectral irradiance of the solar emission. However, in organic solar cells S and EQE can change profoundly with light intensity as a result of processes that vary non-linearly with light intensity such as bimolecular recombination of electrons and holes or space charge effects. To determine the S under representative solar light conditions, it is common to use modulated monochromatic light and lock-in detection in combination with simulated solar bias light to bring the cell close to 1 sun equivalent operating conditions. In this paper we demonstrate analytically and experimentally that the S obtained with this method is in fact the differential spectral responsivity, DS, and that the real S and the experimental DS can differ significantly when the solar cells exhibit loss processes that vary non-linearly with light intensity. In these cases the experimental DS will be less than the real S. We propose a new, simple, experimental method to more accurately determine S and EQE under bias illumination. With the new method it is possible to accurately estimate the power conversion efficiency of organic solar cells.     

基于LT3652的太阳能充电器设计方法

基于太阳能充电器需求的不断增加,采用LT3652电池充电管理芯片设计了一种多功能太阳能充电器。在详细介绍LT3652输入电压调节环路及该芯片的其他功能的基础上,针对设计过程中涉及的元器件选型,PCB布线注意事项作了详细介绍。同时对如何设计更具有生命力和适应性的充电器产品给出了建议。笔者设计的太阳能充电器可实现对光伏电池...     

硅太阳电池扩散方阻均匀性研究

在规模化生产制作单晶硅太阳能电池过程中,控制扩散质量是提升电池质量和效率的关键。在分析了设备及工艺方面存在的影响扩散均匀性因素的基础上,提出了优化扩散均匀性的实验方法,包括：在硅片表面上制作二氧化硅薄膜来减缓磷扩散的速度;在扩散时控制小氮与氧气的流量比例;减少扩散过程中温度波动对扩散结果的影响;在炉口区域设置较高的温度进行温度补偿;调整炉内压强使输入输出达到动态平衡等。试验证明这些方法可以改善电池电性能,并对工业化生产具有一定的参考价值。     

Temperature dynamics of multijunction concentrator solar cells up to ultra‐high irradiance

We report experimental results for the effect of irradiance (from 12 up to 8600 suns) on the temperature coefficients of the key performance parameters of multijunction concentrator solar cells, with a flash‐like, real‐sun optical system. Particular attention is paid to the time scales and magnitudes of junction heating, hence the degree to which the cell can be deemed isothermal. The implications for corresponding measurements from solar simulators with pulsed artificial light and for the performance evaluation of concentrator photovoltaics are also addressed. Copyright © 2011 John Wiley & Sons, Ltd.     

Determination of spectral variations by means of component cells useful for CPV rating and design

A methodology is presented to determine both the short‐term and the long‐term influence of the spectral variations on the performance of multi‐junction (MJ) solar cells and concentrator photovoltaic (CPV) modules. Component cells with the same optical behavior as MJ solar cells are used to characterize the spectrum. A set of parameters, namely spectral matching ratios (SMRs), is used to characterize spectrally a particular direct normal irradiance (DNI) by comparison to the reference spectrum (AM1.5D‐ASTM‐G173‐03). Furthermore, the spectrally corrected DNI for a given MJ solar cell technology is defined providing a way to estimate the losses associated to the spectral variations. The last section analyzes how the spectrum evolves throughout a year in a given place and the set of SMRs representative for that location are calculated. This information can be used to maximize the energy harvested by the MJ solar cell throughout the year. As an example, three years of data recorded in Madrid shows that losses lower than 5% are expected because of current mismatch for state‐of‐the‐art MJ solar cells. Copyright © 2015 John Wiley & Sons, Ltd.     

Using Deep Machine Learning to Understand the Physical Performance Bottlenecks in Novel Thin‐Film Solar Cells

There is currently a worldwide effort to develop materials for solar energy harvesting which are efficient and cost effective, and do not emit significant levels of CO₂ during manufacture. When a researcher fabricates a novel device from a novel material system, it often takes many weeks of experimental effort and data analysis to understand why any given device/material combination produces an efficient or poorly optimized cell. It therefore takes the community tens of years to transform a promising material system to a fully optimized cell ready for production (perovskites are a contemporary example). Herein, developed is a new and rapid approach to understanding device/material performance, which uses a combination of machine learning, device modeling, and experiment. Providing a set of electrical device parameters (charge carrier mobilities, recombination rates, trap densities, etc.) in a matter of seconds thus offers a fast way to directly link fabrication conditions to device/material performance, pointing a way to further and more rapid optimization of light harvesting devices. The method is demonstrated by using it to understand annealing temperature and surfactant choice and in terms of charge carrier dynamics in organic solar cells made from the P3HT:PCBM, PBTZT‐stat‐BDTT‐8:PCBM, and PTB7:PCBM material systems.     

Nanowire and nanohole silicon solar cells: a thorough optoelectronic evaluation

Photovoltaic devices with nanostructured active layers have attracted considerable attention for their outstanding light‐trapping capability. Although with the promise of an efficient light‐conversion, the realistic performance is still far from expectation. This is because the detailed electrical mechanisms have seldom been included into the design, leading to a substantial discrepancy between prediction and reality. This paper reports a complete optoelectronic simulation for nanowire and nanohole solar cells by addressing electromagnetic and carrier‐transport response in a coupled finite‐element method. The effects of surface/bulk recombination are quantified and compared for nanowire and nanohole solar cells with radial and axial doping profiles. Our results reveal that the axially doped silicon cells are extremely sensitive to surface recombination because of the large surface‐to‐volume ratio and lateral recombination loss, eventually reducing the photocurrent and light‐conversion efficiency. Relatively, radially doped silicon cells with a moderate nanowire length show some improvement relative to axially doped cells, but nevertheless remain very sensitive to recombination losses. Comparison of the light‐trapping and electrical performance between nanowire and nanohole solar cells is also given. The methodology is applicable for nanostructured solar cells based on various semiconductor materials and system configurations, and is expected to play a promising role in accurately predicting the performance of the new‐generation light‐conversion devices. Copyright © 2015 John Wiley & Sons, Ltd.