应用于下一代太阳电池的2.05 eV AlGaInP 子电池研究

研制了应用于下一代高效多结太阳电池中的定电池的 Al0.13GaInP子电池,其实验室效率为10.04%,开路电压为1457.3mV,短路电流为11.9mA。使用量子效率来验证MOVPE生长过程中涉及高Al组分引起的O缺陷对电池性能的影响。相比GaInP单结电池,Al0.13GaInP电池的短路电流下降地较为厉害,实验中生长了GaInP/Al0.13GaInP异质结电池来分析其原因,因此也提出了以牺牲部分开路电压来提升短路电流的一种有效提升电池性能的方法。     

GaAs太阳电池的体电阻及旁路漏电对电池结特性的影响

复合电流是液相外延GaAs太阳电池暗电流的主要成分。扫描电镜观察表明,旁路电流主要来源于太阳电池结区的杂质。串联电阻主要来源于电池p型GaAs层的薄层电阻及正面电极的体电阻。串联电阻降低了电池的短路电流,旁路电阻降低了电池的开路电压。减小电池p-GaAs层的薄层电阻是提高电池效率的重要途径。     

连续激光对三结GaAs电池的损伤效应北大核心CSCD

在空气中和真空中,利用波长为1070nm的连续(CW)激光辐照三结砷化镓(GaAs)太阳电池,通过测试激光辐照前后电池的电流-电压曲线,并利用激光诱导电流(LBIC)成像系统和X射线光电子能谱仪(XPS),研究了三结GaAs太阳电池的损伤情况。结果表明,当激光功率密度为8.4 W/cm2、辐照时间为10s时,在空气中,底电池Ge熔融短路;在真空中,顶电池Ga0.5In0.5P和底电池Ge均发生短路,说明三结GaAs太阳电池的底电池最容易受到破坏,且电池在真空中比在空气中更容易受到损伤。该研究结果可为三结GaAs太阳电池的激光无线能量传输和损伤机理的研究提供一定的参考。     

菲涅耳透镜下多结电池表面局部高辐射功率对短路电流的影响

为探索以菲涅耳透镜为聚光器的聚光光伏模组中,多结电池中心局部高辐射功率对短路电流的影响,测量菲涅耳透镜的高亮度光斑直径,并据此分别测试室内不同局部光照面积下和户外不同尺寸透镜下的GaInP/GaInAs/Ge三结电池的短路电流,利用电路网络模型分析实验结果。结果表明,短路电流与局部聚光的面积无关;小尺寸菲涅耳透镜聚焦下,沿光轴电流与辐射功率同步变化;透镜尺寸增大到一定程度,电池中心局部承受过高辐射功率,电流受峰值隧穿电流限制,宏观体现为焦平面处短路电流下降。电池放置在焦平面两侧,均可缓解局部高辐射功率,短路电流最高提升 8.0%。     

MOCVD法制作的12沟道应变层异质结量子阱激光器阵列

采用了选择区外延工艺来制作适用于波分复用的１２沟道应变层ＩｎＧａＡｓ－ＧａＡｓ－ＡｌＧａＡｓ隐埋异质结量子阱激光器阵列。测得单元间的波长间隔为１．９ｎｍ，与２ｎｍ的设计值非常吻合。     

基于石墨烯的肖特基结辐射伏特同位素电池

从传统肖特基结辐射伏特同位素电池金属电极存在的对放射源衰变粒子的阻挡及导电性不理想的问题出发,借鉴石墨烯肖特基结太阳电池结构,将石墨烯/硅肖特基结引入辐射伏特同位素电池中,在63Ni放射源的照射下验证石墨烯/硅肖特基结换能单元在辐射伏特同位素电池中应用的可行性.研究结果发现,基于硝酸掺杂,当少层(3?5层)石墨烯经过4...     

Sb2S3/TiO2纳米管异质结阵列的制备和光电性能

结合水热法和阳极氧化法合成了Sb2S3/TiO2纳米管异质结阵列,采用场发射扫描电子显微镜、X射线衍射谱表征了异质结阵列的形貌和晶体结构.暗态下的电流-电压曲线表明Sb2S3/TiO2纳米管异质结阵列具有整流效应.相比于纯的TiO2纳米管阵列,Sb2S3/TiO2纳米管异质结阵列的光电性能有了显著地提升:在AM1.5标准光强作用下,光电转换效率从0.07％增长到0.40％,表面光电压响应范围从紫外光区拓宽至可见光区.结合表面光电压谱和相位谱,分析了Sb2S3/TiO2纳米管异质结阵列中光生载流子的分离和传输性能.     

β辐射伏特效应电池内建电场厚度设计

计算了放射源在半导体中沿厚度方向的能量沉积,并以此计算β辐射伏特效应电池的理想短路电流。通过对比实测短路电流和理想短路电流可以得到β辐射伏特效应电池PN结内建电场的扩散长度。在上述基础上,本文给出了β辐射伏特效应电池内建电场厚度设计原则： 放射源在半导体中能量沉积厚度和PN结内建电场中载流子的扩散长度两者中较小的应作为β伏特效应电池内建电场厚度设计值,如果沉积厚度远远大于载流子扩散长度,则说明多结结构较适合该类β伏特效应电池果,多结的结数应约为沉积厚度与载流子扩散长度的比。     

高能电子辐照对三结GaAs激光电池特性的影响

研究了能量为1 MeV的电子辐照对三结GaAs激光电池(LPC)性能的影响。不同剂量电子辐照后三结GaAs LPC光照下的I-V特性测试结果表明，三结GaAs LPC短路电流、开路电压和最大输出功率的衰减随电子辐照剂量的提高而增大。通过测量不同波长激光照射下三结GaAs LPC的宽电压范围I-V曲线，确定了各子电池对应的光生电流，结果显示各子电池光生电流衰减随辐照剂量增加而不同程度地增大，越靠近衬底的子电池电流衰退越严重。利用wxAMPS软件模拟了各子电池光生电流随缺陷密度的变化关系，结合实验和模拟结果得到了各子电池辐照后的缺陷密度及缺陷引入率，结果表明各子电池受电子辐照后的缺陷引入率大致相同，约为6.7。可通过优化各结子电池厚度达到提高三结GaAs LPC抗辐照性能的目的。     

基于叠层结构的本体异质结有太阳电池

研究了叠层结构的本体异质结有机太阳电池,下层电池由共轭聚合物(MEH-PPV)作为光敏层,上层电池由共轭聚合物(MEH-PPV)和ZnO纳米颗粒(50nm)组成光敏层.器件结构为ITO/PEDOT:PSS/MEH-PPV/Ag/MEH-PPV:ZnO /Al.与单层有机太阳电池 (ITO/PEDOT:PSS/MEH-PPV/Al) 相比,叠层结构的开路电压VOC是单层电池的3.7倍,短路电流JSC是单层电池的1.6倍.     

槽式聚光太阳能系统太阳电池阵列

基于槽式聚光太阳能系统分别对单晶硅电池阵列、多晶硅电池阵列、空间太阳电池阵列和砷化镓电池阵列进行测试实验. 结果表明,聚光后,前3种电池阵列的I-V曲线都趋于直线,输出功率急剧减少,系统效率下降较快. 而砷化镓电池阵列有较好的I-V曲线,其效率由聚光前的23.66%增加到26.50%,理论聚光比为16.92时,输出功率放大11.2倍,聚光光伏系统中可采用砷化镓电池阵列以提高效率. 砷化镓电池阵列Pm、FF和η的温度系数分别为-0.12W/K、-0.10%/K和-0.21%/K,为避免温度的影响须采用强制冷却方式保证电池效率,同时对外供热. 研究表明,10片单晶硅电池串联阵列最佳工作时的理论聚光比为4.23; 16片空间太阳电池串联阵列最佳工作时的理论聚光比为8.46. 研究工作对提高槽式聚光系统效率和大规模利用聚光光伏发电提供了依据.     

Solar power generation system for reducing leakage current

This paper proposes a transformer-less multi-level solar power generation system. This solar power generation system is composed of a solar cell array, a boost power converter, an isolation switch set and a full-bridge inverter. A unipolar pulse-width modulation (PWM) strategy is used in the full-bridge inverter to attenuate the output ripple current. Circuit isolation is accomplished by integrating the isolation switch set between the solar cell array and the utility, to suppress the leakage current. The isolation switch set also determines the DC bus voltage for the full-bridge inverter connecting to the solar cell array or the output of the boost power converter. Accordingly, the proposed transformer-less multi-level solar power generation system generates a five-level voltage, and the partial power of the solar cell array is also converted to AC power using only the full-bridge inverter, so the power efficiency is increased. A prototype is developed to validate the performance of the proposed transformer-less multi-level solar power generation system.     

低轨卫星太阳电池阵静电放电研究

低轨卫星的高压太阳电池阵与稠密等离子体环境相互作用,发生静电放电会诱发高压电池串间产生二次电弧,从而造成太阳电池阵损伤导致太阳电池阵局部失效。文章介绍了太阳电池阵静电放电的机理,概述了三结砷化镓太阳电池阵静电放电试验环境,分析讨论了试验结果以明确静电放电发生的风险。     

聚光作用下光伏电池阵列性能分析

Performance of concentrating photovoltaic/thermal system is researched by experiment and simulation calculation. The results show that the I-V curve of the GaAs cell array is better than that of crystal silicon solar cell arrays and the exergy produced by 9.51% electrical efficiency of the GaAs solar cell array can reach 68.93% of the photovoltaic/thermal system. So improving the efficiency of solar cell arrays can introduce more exergy and the system value can be upgraded. At the same time, affecting factors of solar cell arrays such as series resistance, temperature and solar irradiance also have been analyzed. The output performance of a solar cell array with lower series resistance is better and the working temperature has a negative impact on the voltage in concentrating light intensity. The output power has a -20 W/V coefficient and so cooling fluid must be used. Both heat energy and electrical power are then obtained with a solar trough concentrating photovoltaic/thermal system.     

光伏并网发电系统的雷电监控系统研究

主要解决户外的太阳电池阵列与户内的控制器和逆变器的避雷防护问题。对户外的太阳电池阵列,采用避雷针防直击雷;对户内的控制器和逆变器采用避雷器与避雷带防雷电感应和雷电波侵入。这种防护方案实现了对光伏并网电站太阳电池阵列、控制器和逆变器的多级、综合雷电防护,并且经济、可行。系统具有重要的科学研究意义和广阔的市场应用前景。     

High performance wire‐array silicon solar cells

Nano/micro‐wire silicon solar cells, consisting of wire‐arrays of radial p–n junction structures, are expected to offer performance enhancement at lower costs, using smaller volumes of low carrier lifetime, cheaper silicon. Using inexpensive microsphere‐lithography‐based fabrication that is scalable to large areas, we have demonstrated wire‐array solar cells that outperform the control cell. Key to the design of these cells is the impact of various parameters, such as wire diameter and junction depth, that influences the competing effects of light trapping ability of the wire‐array, quantum efficiency, and series resistance of the resulting device. Using capacitance measurements we can identify two possible types of junction structure in a wire‐array solar cell: radial and planar. We show that the former is the prerequisite for performance‐enhancing wire‐array solar cells. Copyright © 2010 John Wiley & Sons, Ltd.     

二氧化钛纳米管染料敏化电池的制备和性能

利用两步阳极氧化法,在钛片上成功制备了高质量的二氧化钛纳米管阵列薄膜。利用场发射扫描电子显微镜,对二氧化钛纳米管阵列薄膜进行了形貌表征。之后,将不同厚度的薄膜组装成背光式染料敏化太阳电池,并测量了它们的光电转化性能。发现,随着薄膜层厚度的增加太阳电池的转化效率也逐渐提高。当薄膜厚度为15μm时,电池的转化效率达到3.04%。     

纳米结构在太阳电池中的应用

太阳电池是新能源领域一个不可忽视的领域。随着纳米技术的不断发展,纳米技术和太阳电池有了越来越多的结合点。综述了纳米结构阵列在太阳电池中的应用,其中包括光子晶体、纳米棒阵列、纳米孔阵列、纳米光栅、屋顶状阵列等纳米结构在太阳电池的活性层、减反层以及电极层中的应用。通过提高光吸收、增大p-n结界面比例、提高载流子传输效率等机理提高太阳电池能量转换效率,揭示了纳米结构在降低太阳电池成本、提高太阳电池能量转换效率方面存在的巨大应用潜力。     

Parameters of solar cell arrays

This paper presents an analytically derived method of combining nonidentical solar cell parameters to obtain a single-exponential approximation for an array. It was assumed that the arrayI-Vequation is of the same form as that of the single cell. The array possesses two photocurrents: one at the open circuit voltage and the other depends on load current.     

New Solar Cell Power Supply System Using a Boost Type Bidirectinal DC-DC Converter

A new solar cell power supply system is presented, in which the boost type bidirectional dc-dc converter and the simple control circuit with a small monitor solar cell are employed to track the maximum power point of the solar array. It is confirmed by the experiment that the new system has sufficiently precise tracking operation performance and satisfactorily high power efficiency. Also, a comparison of the power efficiencies is made theoretically, as well as experimentally, on the new and the conventional solar cell power supply systems. As a result, it is revealed that the new system is superior to the conventional one in the power efficiency.