大面积单结a—Si：H太阳电池方阵现场稳定性的评价与测试方法

对不同工作状态的２７８７ｃｍ＾２单结集成型ａ－Ｓｉ：Ｈ太阳电池组件室外１年多的实验结果与２ｋＷａ－Ｓｉ：Ｈ太阳电池方阵现场运行４年多的结果进行比较，说明组件或方阵在室外运行１年后，经过正常衰退阶段，其性能趋于稳定。同时给出了大功率ａ－Ｓｉ：Ｈ太阳电池方阵性能的现场测试方法。     

太阳电池硅片ELCC技术用复合梯度涂层的研究

低成本太阳电池硅片电磁悬浮熔炼离心铸造（ＥＬＣＣ）技术可大幅度降低太阳电池的成本。硅片脱模技术是ＥＬＣＣ技术的关键之一。综合运行液相反应生成法，反应烧结法和溶胶－凝胶法，成功地在石墨基体表面制备了ＳｉＣ－Ｓｉ３Ｎ４－（Ｓｉ３Ｎ４＋ＳｉＯ２）复合梯度涂层，并用Ｘ射线衍射法（ＸＲＤ）、扫描电镜（ＳＥＭ）和界面性能测定仪（ＩＣＭ）考察了该涂层的组织结构和性能。     

高效非晶硅叠层太阳电池的优化设计

研究了高效ａ－Ｓｉ／ａ－Ｓｉ／ａ－Ｓｉ－ＳｉＧｅ三结太阳电池的优化设计。电流匹配是影响二端子叠层太阳电池填充因子的关键因素，在内电极的ｐ／ｎ界面外附加载流子复合是由少数载流子浓度、界面态和ｐ／ｎ界面处材料的几何因素匹配决定的。利用适当的带隙匹配和ｉ层厚度匹配来实现ａ－Ｓｉ／ａ－Ｓｉ／ａ－ＳｉＧｅ三结太阳电池结构的最佳化，同时采用改善ｎ／ｉ界面特性的缓冲层技术，获得了Ｖｏｃ＝２．４８Ｖ，Ｊｓｃ＝６．     

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。     

SiC材料制备方法及碳热还原反应的分析

本文对ＳｉＣ颗粒，晶须和纤维的制备方法和碳热还原反应作了探讨，碳热还原反应作了制备ＳｉＣ材料的主要反应可分为两个基本过程，首先为ＳｉＯ气的产生，其次ＳｉＯ直接与Ｃ反应生成ＳｉＣ或ＳｉＯ成硅再与Ｃ反应生成ＳｉＣ。     

p／i界面的缓变层对大面积（2790cm^2）a—Si：H太阳电池性能影响的研究

报道了在大面积（２７９０ｃｍ２）ｐ－ｉ－ｎ型ａ－Ｓｉ∶Ｈ异质结太阳电池ｐ／ｉ界面之间引入缓变层（ＣＧＬ∶Ｃ，ＣＧＬ∶Ｂ∶Ｃ）对电池性能影响的研究结果。实验发现，带有ＣＧＬ∶Ｃ的ａ－Ｓｉ∶Ｈ太阳电池性能的改善主要来源于开路电压的提高，带有ＣＧＬ∶Ｂ∶Ｃ的ａ－Ｓｉ∶Ｈ太阳电池性能的提高主要来源于填充因子ＦＦ的增加。提出了带有缓变层ａ－Ｓｉ∶Ｈ电池的能带模型，据此分析了ｐ／ｉ结附近载流子的复合动力学过程，从理论上解释了实验中所发现的现象。     

MIS／IL硅太阳电池耐紫外辐射性能的研究

通过比较蒸发铯和浸渍铯在ＭＩＳ／ＩＬ硅太阳电池中所引入的铯量、固定正电荷量、界面态密度和对太阳电池表面面电阻的影响，以及测量上述诸量和太阳电池的主要参数经紫外辐照后的变化，并从表面能带的角度分析了引入铯对太阳电池的紫外辐射稳定性的影响，解释了在ＭＩＳ／ＩＬ硅太阳电池中引入铯使该器件耐紫外辐射性能提高的原因。     

类p—i—n结构n^＋（μc—Si：H）／p（poly—Si）p^＋（poly—Si）薄膜太阳电池的热平衡

通过应用Ｓｃｈａｒｆｅｔｔｅｒ－Ｇｕｍｍｅｌ解法，数值求解Ｐｏｉｓｓｏｎ方程，对热平衡态ｎ＾－（μｃ－Ｓｉ：Ｈ）／ｐ（ｐｏｌｙ－Ｓｉ）ｐ＾＋（ｐｏｌｙ－Ｓｉ）薄膜太阳电池进行计算机数值模拟。     

快速汽相沉积法制备硅薄膜太阳电池

对在重掺杂抛光单晶硅衬底上用ＲＴＣＶＤ法形成硅薄膜太阳电池进行了研究。衬底为〈１００〉晶向ｐ＋ ＋ 型重掺硅片,电阻率为５×１０－ ３Ωｃｍ 。主要工艺过程为：在衬底上生长一层硅薄膜同时掺硼,膜厚３８μｍ ,扩磷制备ｐ－ｎ 结,背面蒸Ａｌ及Ｔｉ／Ｐｄ／Ａｇ 制背电极,正表面在扩散后生长一层ＳｉＯ２ ,前面用光刻剥离法制备Ｔｉ／Ｐｄ／Ａｇ 电极,制成的１ｃｍ ２ 太阳电池,开路电压ＶＯＣ＝ ６１２．８ｍ Ｖ,短路电流ＩＳＣ＝ ２９．３ｍ Ａ,填充因子ＦＦ＝ ０．７５７９,效率η＝ １３．６１。对一些影响电池特性的因素进行了研究,发现硅薄膜的掺杂浓度、发射层的掺杂浓度以及减反射层都对太阳电池的特性有较大影响。     

晶体硅薄膜太阳电池的衬底材料--颗粒硅带(SSP)的制备

晶体硅薄膜太阳电池（CSiTF-Crystalline Silicon Thin Film Solar Cells)由于具有降低制造成本的空间， 成为目前研究工作的一 个热点。我们将注意力集中在低成本、可连续化的硅衬底制备上，即颗粒硅带（SSP-Silicon Sheet from Powder)制备技术。可以使用不同纯度、粒度的硅粉，经过光聚焦加热熔化，最后得到不同长度、宽度和厚度的颗粒硅带衬底材料。介绍了晶体硅薄膜太阳电池衬底材料的现状，并描述实验室的颗粒硅带制备技术。     

Polycrystalline silicon solar cells on low cost foreign substrates

The use of polycrystalline silicon layers on low-cost substrates is a promising approach for the fabrication of low-cost solar cells. Using low-carbon steel and graphite as substrates, solar cell structures have been deposited by the thermal decomposition of silane and appropriate dopants.Steel was selected as a substrate on the sole basis of its low cost. However, steel and silicon are not compatible in their properties, and an interlayer of a diffusion barrier, such as borosilicate, must be used to minimize the diffusion of iron from the substrate into the deposit. The deposited silicon on borosilicate/steel substrates is polycrystalline with a grain size of 1–5 μm, depending on deposition conditions. P-n junction solar cells were found to have low open-circuit voltages and poor current-voltage characteristics, and Schottky-barrier solar cells were found to show negligible photovoltages.Graphite is more compatible with silicon in properties than steel, and silicon deposited on graphite substrates shows considerably better microstructures. A number of solar cells, 2·5×2·5 cm in area, have been fabricated from n⁺-silicon/p-silicon/p⁺-silicon/graphite structures. The best cell to date had a V_oc of 0·35 V and an AMO efficiency of 1·5% (no antireflection coating). This type of solar cell is very promising because of the simplicity in fabrication.     

Recovery of minority carrier lifetime in low-cost multicrystalline silicon

Lifetime of minority carriers has been widely identified to be the key material parameter determining the conversion efficiency of pn-junction silicon solar cells. Impurities and defects in the silicon crystal lattice reduce the charge carrier lifetime and thus limit the performance of the solar cells. Removal of impurities by silicon material purification is often contradictory with low cost production of photovoltaic devices. In this paper, we present experimental results of an efficient gettering technique which can be applied to low cost processing of multicrystalline silicon solar cells without any additional process steps or compromises with optimal device design parameters. This technique is based on well-known phosphorous gettering. We have discovered that if the silicon wafers are kept in the furnace after the emitter diffusion at the 700°C, significant improvement in the lifetime will take place. At this temperature the properties of the pn-junction remain unaffected meanwhile many lifetime killers are still mobile. The time needed for this temperature program can be easily modified in order to respond to the material quality variations in substrates originating from different parts of multicrystalline ingot. Better control of lifetime can lead to higher degree of starting material utilization.     

Analysis of a hybrid nanofluid exposed to radiation

ABSTRACT

Researchers are looking to utilize nanofluids as a way to increase the efficiency in solar energy applications. Metallic particles are becoming popular because of the plasmonic characteristics allowing for more absorption. Only homogenous nanofluids for solar applications have been considered. This article proposes the use of a hybrid nanofluid containing multiple types of nanoparticles with water as the base fluid exposed to radiation. This hybrid mixture can utilize a broader wavelength spectrum and absorb more heat. Recipes for combining gold, copper, aluminum, graphite, and silicon dioxide gold nanoparticles into water are given graphically and numerically for different concentrations, diameters, and container heights.     

烧结曲线对多晶PERC太阳电池光致衰减效应的影响

针对多晶PERC太阳电池其较大的光衰效应会影响功率输出的问题,研究烧结曲线对多晶PERC太阳电池光致衰减效应的影响。在常规烧结曲线1的基础上通过改变烧结曲线峰值温度位置得到优化烧结曲线2和优化烧结曲线3,然后将双面沉积Al2O3/SiNx叠层钝化膜的寿命片和丝网印刷后的多晶PERC电池分别采用不同烧结曲线热处理,最后将样品在70℃、800 W/m2环境下进行45 h光衰处理。结果发现经过烧结曲线1~曲线3处理后的寿命片少子寿命衰减率分别为63%、42%和23%,多晶PERC太阳电池转换效率的衰减率分别为6.46%、3.55%和2.30%,光衰处理后的多晶PERC电池的EL测试结果显示烧结曲线1亮度最小,曲线2次之,曲线3最大。以上结果表明,仅通过烧结炉的烧结曲线优化就可以很明显地减小多晶PERC太阳电池的光致衰减幅度,可为探究抑制多晶PERC太阳电池光致衰减效应的方法提供一种全新的思路。     

Spherical antireflection coatings by large-area convective assembly of monolayer silica microspheres

Solution-processed surface textures are highly desirable for antireflection in high-performance cost-effective solar cells. Inorganic spherical surface textures can be formed with monolayers of microscale silica spheres partially immersed into spin-on-glass films. We report here a convective assembly process for the formation of large-area self-assembled monolayers of silica microspheres on glass, quartz, and silicon substrates. The structure of the self-assembled monolayers and their spatial extent are significantly influenced by sphere concentration in the suspension, dispersed suspension volume, solvent, coating plate speed, and wedge angle. Glass substrates up to 150×150 mm² are uniformly coated with monolayers of 2-μm silica spheres. It is found that the spherical coating improves the transmittance of quartz wafer from 89.2% to 92.7% around 400 nm and from 90.8% to 92.5% around 1100 nm, demonstrating its broad-spectrum nature. The spherical structure offers an attractive solution to antireflection in crystalline silicon solar cells, as well as thin-film, quantum dot, organic, and flexible solar cells.     

On the stability of optical properties of antireflection coatings for solar cells based on a silicon-silicon-oxide mixture

It is investigated how the storage duration influences the optical properties of antireflection coatings based on silicon-silicon-oxide mixture intended for silicon solar cells. It is shown that the spectral reflection coefficient changes by 2.7% for 22 years; i.e., the antireflection effect is retained. We draw the conclusion that coatings based on silicon-silicon-oxide mixture can greatly increase the lifetime of solar cells and a solar battery.     

Large-size multi-crystalline silicon solar cells with honeycomb textured surface and point-contacted rear toward industrial production

In this paper, we present a multi-crystalline solar cell with hexagonally aligned hemispherical concaves, which is known as honeycomb textured structure, for an anti-reflecting structure. The emitter and the rear surface were passivated by silicon nitride, which is known as passivated emitter and rear (PERC) structure. The texture was fabricated by laser-patterning of silicon nitride film on a wafer and wet chemical etching of the wafer beneath the silicon nitride film through the patterned holes. This process succeeded in substituting the lithographic process usually used for fabricating honeycomb textured structure in small area. After the texturing process, solar cells were fabricated by utilizing conventional fabrication techniques, i.e. phosphorus diffusion in tube furnace, deposition of anti-reflection film and rear passivation film by chemical vapor deposition, front and rear electrodes formation by screen printing, and contact formation by furnace. By adding relatively small complicating process to conventional production process, conversion efficiency of 19.1% was achieved with mc-Si solar cells of over 200 cm² in size. The efficiency was independently confirmed by National Institute of Advanced Industrial Science and Technology (AIST).     

Production of hydrogen by thermal methane splitting in a nozzle-type laboratory-scale solar reactor

A high-temperature solar reactor has been developed for co-producing hydrogen-rich gas and high-grade carbon black (CB) from concentrated solar energy and methane. The approach is based on a single-step thermal decomposition (pyrolysis) of methane without catalysts and without emitting carbon dioxide since solid carbon is sequestered.In the tested reactor, a graphite nozzle absorbs concentrated solar radiation provided by a solar furnace. The heat is then transferred to the reactive flow. The experimental setup, first test results, and effect of operating conditions are described in this paper.The conversion of methane was strongly dependant on the solar furnace power input, on the geometry of the graphite nozzle, on gas flow rates, and on the ratio of inert gas-to-reactive gas. CB was recovered in the carbon trap, and maximum chemical conversion of methane-to-hydrogen and CB was 95%, but typical conversion was in the range 30–90%.     

Role of hydrazine monohydrate during texturization of large-area crystalline silicon solar cell fabrication

Reduction of optical losses in monocrystalline silicon solar cells by surface texturing is one of the important issues of modern silicon photovoltaic. For texturization during commercial monocrystalline silicon solar cell fabrication, a mixture of NaOH or KOH and isopropyl alcohol (IPA) is generally used in order to achieve good uniformity of pyramidal structure on the silicon surface. The interfacial energy between silicon and electrolyte should be reduced in order to achieve sufficient wettability for the silicon surface which in turn will enhance the pyramid nucleation. In this work, we have investigated the role of hydrazine monohydrate as a surface-active additive, which supplies OH⁻ ions after dissociation. This cuts down the IPA consumption during texturing without any loss of uniformity of textured pyramid. We are probably the first group to report such a novel idea of using hydrazine monohydrate addition in NaOH solution for texturization of solar cell. We were able to fabricate monocrystalline silicon solar cells with more than 85% yield in the range of 14–15% efficiency.     

Induction melting process using segmented graphite crucible for silicon melting

Induction melting process using segmented graphite crucible was investigated to melt silicon feedstock for solar cells. Induction melting is the key technology used in silicon melting process, such as ingot-growing, metallurgical refining and ribbon production. However, contamination of silicon from the crucible in induction melting is the main source of degrading the silicon. In this paper, new structure of crucible was suggested to minimize the contamination from the crucible wall. It was the segmentation of graphite crucible wall that introduced the non-contact between melt and inner wall of crucible. Numerical and experimental studies of induction melting process of silicon using the suggested crucible were conducted. For numerical analysis, 3D models of crucible, induction coil and silicon were constructed and electromagnetic force and temperature distribution in silicon and crucible were calculated. To evaluate a process with the suggested crucible, induction melting system was built up based on the simulated results and experiments of silicon melting were carried out.