用于GaInP/GaAs双结叠层太阳电池的MOVPE外延材料

采用金属有机化合物气相淀积(MOVPE)技术生长用于GaInP/GaAs双结叠层太阳电池的外延材料。针对材料生长中的隧穿结、p-AlInP层等关键问题,通过对掺杂剂、生长技术及条件的调整与改进,极大地提高了GaInP/GaAs双结叠层太阳电池性能,最高转换效率达到23.8%(AMO,25℃)。     

国产GaAs/Ge太阳电池在轨行为评价

研究了电子和质子辐照下国产GaAs/Ge太阳电池电学性能退化规律。结果表明:小于200keV质子辐照下国内外GaAs/Ge电池等效损伤系数明显不同,原因是国内外太阳电池结构参数的不同引起的。高能质子和电子辐照下,国内外电池等效损伤系数结果相近,和电池结构关系不大,这是由于高能质子和能够造成电池位移损伤的电子更容易穿透电池,在电池中产生均匀损伤。通过计算透过防护盖片后的带电粒子能谱对JPL(Jet Propulsion Labo-ratory)的等效注量法进行了改进,在地球同步轨道环境下评价了国产GaAs/Ge太阳电池的在轨行为。     

在导电玻璃衬底上热壁外延生长GaAs薄膜

该文报道以导电玻璃为衬底,采用热壁外延方法,制备GaAs多晶薄膜材料.采用电子探针(EPMA)测定薄膜的组分、表面与剖面形貌,x射线衍射(XRD)分析生长薄膜的结构,Raman散射(RSS)、光致发光光谱(PL)分析其光学性能.结果表明该薄膜性能良好、表面呈绒面结构、适合制作GaAs薄膜太阳电池.并全面分析了现有制备工艺条件对GaAs薄膜性能的影响,得出最佳的生长温度条件源温为900～930℃,衬底温度为500℃.     

非晶／微晶硅叠层电池中间层的研究进展

由于非晶硅光致衰退、微晶硅吸收系数低的原因,叠层结构电池成为提高电池效率和稳定性的有效途径.叠层电池各子电池较薄、太阳光的利用率较低,因此陷光结构在叠层电池中的作用尤其重要.具有绒面结构的前电极、叠层电池的中间层以及ZnO/Al或ZnO/Ag复合背电极共同组成硅薄膜太阳电池的陷光结构.中间层位于各子电池之间,作用是改变界面反射率,影响电池中光的传播路径.该文综述了叠层电池中间层的作用、要求以及此方面国内外的研究现状,并指出中间层研究中需要注意的主要问题和未来发展的趋势.     

多晶硅电池叠层抗反射层的设计研究

根据多晶硅电池对表面抗反射薄膜设计的需要,基于薄膜反射特征导纳矩阵理论结合电池的背底反射,建立了完善的表面反射和电池吸收计算模型,在已知薄膜复折射率的前提下可给出反射率的精确计算结果.利用该计算模型,设计了多种表面反射结构,其中硅量子点镶嵌氮化硅与二氧化硅组成的双层抗反射薄膜,在AM1.5光谱下其积分反射率最低可达到4.38％；分析了不同硅量子点体积比对于该双层抗反射膜的影响,系统给出了实际生长该双层抗反射层的具体参数,即富硅氮化硅中的Si:N=1:1时即可达到较好的表面抗反射效果.     

外量子效率测试在GaInP/GaInAs/Ge三结太阳电池接收器性能评估中的应用

利用太阳电池量子效率测试系统对GaInP/GaInAs/Ge三结太阳电池接收器进行检测和分析,从而修补了系统缺陷,对外量子效率测试中发现的问题进行了初步探索和解决。借助GaInP/GaInAs/Ge三结太阳电池的等效电路模型,根据三结结构中各个子电池的短路电流值、调整偏置光和偏置电压,改进了测试中的偏置滤光片问题,提出了该太阳电池接收器的性能评估方法和判断依据。     

400cm2 a-Si/a-Si叠层太阳电池的研究

以全部国产化装备和工业用原材料，以简单铝背电极制备出初始效率为８．２８％，经室外阳光照射一年后稳定效率为７．３５％，面积为２０ｃｍ×２０ｃｍ，有效面积为３６０ｃｍ２ａ－Ｓｉ／ａ－Ｓｉ叠层太阳电池。主要制备技术措施：（１）ＴＣＯ／ｐ界面接触特性的改善；（２）μｃ－ＳｉＣ∶Ｈ／ａ－ＳｉＣ∶Ｈ复合窗口层技术；（３）ｐ／ｉ界面Ｈ处理；（４）高质量本征ａ－Ｓｉ∶Ｈ材料；（５）优良的ｎ１／ｐ２隧道结；（６）最佳电池结构设计等。     

生长条件对GaAs/Si薄膜结构特性的影响

该文介绍以单晶Si为衬底,热壁外延制备适合作太阳电池的GaAs多晶薄膜.采用电子探针(EPMA)测定薄膜的组分、表面与剖面形貌,x射线衍射(XRD)分析生长薄膜的结构特性.并分析了各种工艺条件对GaAs薄膜结构特性的影响,得出制备表面呈绒面结构、晶粒为柱状结构、可用作廉价、高效GaAs太阳电池衬底的多晶薄膜材料的最佳生长条件源温为900℃,衬底温度为700℃,生长时间为3h.     

全站仪坐标测量在导线测量中的应用

介绍采用蔡司C 20全站仪直接测定控制点三维坐标进行导线测量的作业方法,突破了传统的导线测量模式,不需分别测边、测角及内业计算就可自动测定三维坐标并自动平差。该方法操作简便、自动计算检核、精度高,可在水电工程中推广应用。     

现代测量技术在煤矿测量中的应用分析

现代测量技术在煤矿测量中的应用具有重要性与必要性。叙述并分析了全站仪、全球定位系统、三维激光技术、惯性测量系统以及遥感测量技术等现代测量技术在煤矿测量中的应用。     

GaInP single junction and GaInP/GaAs two junction thin-film solar cell structures by epitaxial lift-off

The epitaxial lift-off (ELO) technique was used in forming a thin-film GaInP/GaAs two-junction monolithic tandem solar cell structure. First, the GaInP single junction solar cell to be used in the tandem cell structure as a top cell was thinned by the ELO process. Although the ELO process and the transfer to the quartz substrate caused a strain in the thin-film cell after separation from the GaAs substrate, the photoluminescence peak intensity was not decreased. This shows that defects, such as those causing carrier loss, were not introduced on the thin-film cell during the thinning process. The key issue for thin-film cell fabrication is to avoid damaging the AlInP window layer during the selective etching (HF etchant), by which the thin-film cell is released from the GaAs substrate. A GaInP/GaAs monolithic tandem structure was also thinned by the same process with a GaInP single junction cell. Characteristics of the single-junction GaInP cell and individual cells in the GaInP/GaAs tandem structure were examined. It was found that the spectral response remains almost the same as that for cells with a GaAs substrate, thus confirming the feasibility of using the ELO process to fabricate thin-film GaInP/GaAs cells.     

Optimal growth procedure of GaInP/GaAs heterostructure for high-efficiency solar cells

We have developed an optimal growth procedure for gas-source MBE production of a GaInP/GaAs heterointerface. The interface quality is crucial to obtaining high-performance GaAs solar cells with a GaInP barrier layer because minority carrier lifetime depends strongly on the interface structure. In situ Reflective High-Energy Electron Diffraction (RHEED) observation during the growth across the GaInP/GaAs heterointerface revealed that the phosphorus atoms are replaced by arsenic atoms in the near-interface region of the GaInP layer, and a transient layer acting as a carrier trap is formed. Introduction of a GaP layer into the interface was found to be effective in suppressing carrier loss. From Composition Analysis by Thickness Fringe-Transmission Electron Microscopy (CAT-TEM) images, it was also found that the optimum thickness of inserted GaP to avoid the generation of misfit dislocations is 1 nm.     

AlxGa1—xAs／GaAs太阳电池减反射膜的研究

以太阳电池的短路电流积分表达式为依据，应用减反射膜的光学原理，对具有阳极氧化、ＳｉＯ和ＳｉＯ２三种减反射膜的ＡｌｘＧａ１－２Ａｓ／ＧａＡｓ太阳电池分别进行了反射光谱、短路电流、开路电压的实验测试。研究表明，阳极氧化膜、ＳｉＯ膜具有良好的减反射性能，而ＳｉＯ２膜的减反射性能较差。     

InGaP/GaAs双结太阳电池的研制

报导了自行研制的InGaP/GaAs双结太阳电池，电池的转换效率在21％-24％之间(1AM0，28℃)，填充因子在79％-82％之间。文中对其材料结构设计、器件工艺制作以及性能测量表征等方面的问题进行了讨论。     

AlxGa1-xAs/GaAs太阳电池MgF2/ZnS双层减反射膜的研究

介绍了在AlxGa1-xAs/GaAs太阳电池上制备MgF2/ZnS双层减反射膜的研究工作,引入了有效反射率R,并通过使Re极小来实现减反射膜的优化设计,考虑了MgF2/ZnS双层减反射膜与窗口层的耦合,实验上获得了良好的减反射膜,提高了AlxGa1-xAs/GaAs太阳电池的短路电流和效率,表明用Re极小化来设计减反射膜是合理的。     

用于高效级联太阳电池的ZnSe材料研究

研究了用于高效Znse／GaAs/Ge(硒化锌绅化镓／锗)级联太阳电池顶电池的ZnSe材料。用MBE技术制备了ZnSe p-n结样品，测量了其外量子效率；提出了改进ZnSe顶电池性能的方法；分析了ZnSe／GaAs／Ge结构比GaInP／GaAs／Ge结构的优越之处。     

Process damage free thin-film GaAs solar cells by epitaxial liftoff with GaInP window layer

We report on process damage free thin-film GaAs cells detached from the GaAs substrates. GaAs cells grown by gas-source MBE were thinned by the epitaxial liftoff (ELO) technique. Photoluminescence spectroscopy showed a peak splitting in the band emission, indicating that a strain was induced in the thin-film cell fixed on the quartz glass substrate. The strain, however, was found not to affect the quality of the thin-film cells, based on the fact that the peak intensity was almost twice that before ELO. The thin-film GaAs cells showed no evidence of degradation in diode characteristics and spectral responses. The keys to avoiding damage on the active region of the solar cell during the thinning process are the introducing a GaInP window layer and improving the thin film process including metallization on thin film cells. These results demonstrates that the thinning and transfer processes dol-not affect the quality of the active region of the cells.     

Light-splitting photovoltaic system utilizing two dual-junction solar cells

There are many difficulties limiting the further development of monolithic multi-junction solar cells, such as the growth of lattice-mismatched material and the current matching constraint. As an alternative approach, the light-splitting photovoltaic system is investigated intensively in different aspects, including the energy loss mechanism and the choice of energy bandgaps of solar cells. Based on the investigation, a two-dual junction system has been implemented employing lattice-matched GaInP/GaAs and InGaAsP/InGaAs cells grown epitaxially on GaAs and InP substrates, respectively.     

GaAs/Ge solar cell AC parameters under illumination

The ac parameters of GaAs/Ge solar cell were measured under illumination at different cell temperatures using impedance spectroscopy technique. They are compared with the dark measurements. It is found that the cell capacitance is higher and cell resistance is lower under illumination than in dark for all cell terminal voltages. The cell capacitances at the corresponding maximum power point voltage (terminal) do not vary with temperature where as the cell resistance decreases. The cell capacitance under illumination is estimated from the dark cell capacitance and it is in good agreement with the measured illumination data.