这项研究得到为中心的能源纳米，由能源，科学办公室根据奖号DE-SC0001013美国能源部资助的能源前沿研究中心的一部分。我们还要感谢张兆旭博士和杨建华惠普实验室的博士它们对二氧化钛薄膜溅射和折射率测量帮助。

1.准备空白聚二甲基硅氧烷（PDMS）为基材纳米压印模具<ol><li>硅片处理工艺<ol><li>通过用丙酮，甲醇和异丙醇漂洗清洗4英寸的硅晶片。 </li><li>吹干使用氮气枪。 </li><li> （:硫酸，用30％的过氧化氢的混合物3）通过浸泡内15分钟用食人鱼溶液清洗。 </li><li>用去离子水冲洗。使用氮气枪吹干。 </li><li>放置在玻璃干燥器的晶片。添加脱模剂（三氯硅烷）进入干燥器的下降（20滴= 1毫升）。 </li><li>抽空干燥器，直到压力表读数-762​​托，等待5小时。 </li><li>取晶片出来，这已经用脱模剂。 </li></ol></li><li> PDMS薄膜的制备（用作模具在纳米压印） <ol><li>称取将10克硅橡胶基地和1克固化剂。 </li><li>添加它们以相同的玻璃烧杯中。 </li><li>性病r和混合用玻璃棒5分钟。 </li><li>将混合物放入真空干燥器中，直至压力表读数-762​​乇泵出所有夹带的气泡。 </li><li>均匀地散布到他们的处理4英寸硅晶片。 </li><li>烘烤在顶部的真空烘箱中7小时的PDMS晶片在80℃下，以固化的PDMS膜。 </li></ol></li></ol> 2.（从母模复制）准备纳米压印模具<ol><li>旋12滴（20滴= 1毫升）的UV可固化抗蚀剂（15.2％）干净的空白硅晶片上30秒以1,500rpm。 </li><li>小心剥离一块PDMS膜关闭处理的硅晶片。 </li><li>放的PDMS薄膜上的紫外线固化性抗蚀剂，并让它吸收UV抗蚀剂进行5分钟，然后把它剥开。 </li><li>重复2.1-2.3在相同的PDMS膜两次。吸收UV分别抗蚀3分钟和1分钟。 </li><li>将PDMS膜（后三次抵抗紫外线吸收）到硅模具师傅。 </li><li>把它放入用氮气环境的腔室。 </li><li>打开紫外灯，以固化样品5分钟。 </li><li>剥离PDMS膜。固化的紫外线抗蚀剂上的PDMS将保持母模的负图案。 </li><li>利用射频O 2等离子治疗的PDMS模具。 （RF功率:30W，压力:260毫乇，时间:1分钟） </li><li>将PDMS模具在真空室中带脱模剂2小时的一滴（20滴= 1毫升）。 </li></ol> 3.纳米压印图案转印<ol><li>在基片上旋8滴（20滴= 1毫升）的PMMA（996k，3.1％），以在3,500rpm进行压印，50秒。 </li><li>烤它在热板上进行5分钟，在120℃。 </li><li>等待样品冷却下来。 </li><li>旋8滴（20滴= 1毫升）的UV可固化抗蚀剂（3.9％），在同一基板上。 </li><li>放置的PDMS模具（在步骤2中制备的）在样品上（与两个紫外抗蚀剂和聚甲基丙烯酸甲酯）。 </li><li>把它放入用氮气环境的腔室。</li><li>打开的紫外灯固化5分钟。 </li><li>剥离的PDMS模具关闭样品和在PDMS模具的图案被转移到样品。 </li></ol> 4.铬剥离工艺<ol><li>反应离子蚀刻紫外线残留抗蚀剂层和聚甲基丙烯酸甲酯 注:为SOP机器ICP可在https://www.nanocenter.umd.edu/equipment/fablab/sops/etch-07/Oxford%20Chlorine%20Etcher%20SOP.pdf发现<ol><li>登录RIE威达机械。 </li><li>放入空白4英寸硅片。运行清洁配方10分钟。 </li><li>就拿空白硅片出。 </li><li>安装样品上的另一个干净的硅晶片，并加载到机器。 </li><li>运行紫外抗蚀剂蚀刻配方为2分钟（配方在表1中找到）。 </li><li>取样品出来。放入空白4英寸硅片。重新运行清洁配方10分钟（在表1中可以找到）。 </li><li>装载样品清洁硅晶片上并将其加载到机器。 </li><li>运行的PMMA的蚀刻配方（可在表1中可以找到）2分钟。 注意:现在的残留抗蚀剂已经蚀刻和基材暴露。 </li></ol></li><li>铬电子束蒸发<ol><li>登录到电子束蒸发器。 </li><li>加载的Cr金属源和样品放入室中。 </li><li>置的厚度（20 nm），而沉积速率（0.03纳米/秒）。 </li><li>泵送腔室，直到所需的真空（10 -7乇）为止。 </li><li>启动沉积过程。 </li><li>取样品从沉积结束后。 </li></ol></li><li> CR剥离过程<ol><li>沉浸样品在丙酮超声搅拌5分钟。 </li><li>通过用丙酮，甲醇和异丙醇漂洗清洁样品。 注意:铬蒸镀在抗蚀剂将被剥离，并形成一个Cr掩膜对基板蚀刻。 </li></ol></li></ol> 5. 二氧化钛德普osition <ol><li>加载样品。 </li><li>设置参数直流磁控溅射镀膜机<ol><li>使用1.5毫托的室压力，以100sccm Ar流量为130 W·溅射功率</li><li>使用27℃的温度和20 rpm的阶段转动速度。 </li></ol></li><li>启动溅射处理，并停止在所希望的厚度。 </li><li>取样品出来，退火在氧气环境中的TiO 2膜在300℃下3小时。 </li></ol> 6.高对比度光栅刻蚀<ol><li>登录在感应耦合等离子体（ICP）的反应离子蚀刻（RIE）的机器。 </li><li> TiO 2的蚀刻<ol><li>放入空白4英寸硅晶片。 </li><li>启动和运行的洁净配方10分钟（在表1中可以找到）。 </li><li>卸载装载晶圆空白和负载与Cr掩膜样品。 </li><li>设置蚀刻时间。开始TiO 2的蚀刻配方。蚀刻过程中会自动matically停止。 </li><li>卸载样品。 </li></ol></li><li> SiO 2的蚀刻<ol><li>除了 ​​使用SiO 2的蚀刻配方重复步骤5.2。 </li></ol></li></ol> 7.反射测量仪<ol><li>登录并打开测量系统。 </li><li>放置在试样保持器的反射率标准镜子和对准的光路。 </li><li>校准系统为100％的反射率。 </li><li>取下反射镜的标准，然后将HCG。 </li><li>测量HCG的反射率。 </li><li>保存数据并注销测量系统。 </li></ol>

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The authors have nothing to disclose.

首先，在TiO 2膜的质量对于HCG的性能非常关键。反射率峰值将更高，如果在TiO 2膜具有较少损耗和表面粗糙度。在TiO 2膜具有更高的折射率也是有利的，因为该光学模式限制将通过在指数更高的对比度，从而可以产生更平坦和更广泛的反射带中的HCG来增强。 第二，在制造误差会对HCG显著影响，应加以避免。在制造中引入的粗糙度会导致更多的光被散射?...

无需移动能量消耗的显著一部分可再生能源现代社会将无法生存。要做到这一点，我们必须找到一种方式的成本比在不久的将来，石油为主的能源更低的收获可再生能源。太阳能是地球上最丰富的可再生能源。尽管很多进展的已在太阳能收集，它仍然是非常具有挑战性的，用石油为基础的能源竞争。提高太阳能电池的效率是最有效的方法来降低的太阳能收集系统的成本之一。 光学透镜和盘的反射器通常用在最浓的光伏（CPV）系统1，实现了高浓度对小面积的太阳能电池的太阳能发电率，所以它是经济上可行的利用昂贵串联多结太阳能电池2中CPV系统，并保持合理的成本的同时。然而，对于大多数非集中光伏系统，其通常需要的太阳能电池的大面积装置，高成本叠层太阳电池不能掺入，尽管它们通常具有更广阔的太阳光谱响应和比更高的总转换效率单结太阳能电池3。 最近，与并行光谱分裂光学器件的帮助下（ 即色散元件），平行光谱分裂光伏技术4使得有可能，类似的或更好的频谱覆盖范围和转换效率，而无需使用昂贵的串联型太阳能电池来实现。太阳光谱可以被分成不同的频带，每个频带可以被吸收并转换为电的专门的单结太阳能电池。以这种方式，昂贵的串联型太阳能电池中CPV系统可通过单结太阳能电池的并行分布来代替•不用对性能的任何折衷。 这是设计本报告中的色散元件可以在反射的CPV系统（它是基于盘反射器），以实现平行的频谱分割为改进太阳能电转换效率和降低的成本施用。多层高对比度光栅（HCG）5用作色散元件通过设计的HCG各层工作作为光学带反射器。的结构和色散元件的参数进行数值优化。此外，高对比度的光栅的制造通过使用电介质色散元件（ 二氧化钛）溅射，纳米压印光刻6和反应离子蚀刻进行了研究和论证。

<table><tbody><tr><td>184 Silcone elastomer kit</td><td>Sylgard</td><td></td><td>Polydimethylsiloxane (PDMS)</td></tr><tr><td>4 inch silicon wafer</td><td>Universitywafer</td><td></td><td></td></tr><tr><td>4 inch fused silica wafer</td><td>Universitywafer</td><td></td><td></td></tr><tr><td>Poly(methyl methacrylate)</td><td>Sigma-Aldrich</td><td>182265</td><td></td></tr><tr><td>UV-curable resist</td><td></td><td></td><td>Nor available on market</td></tr><tr><td>PlasmaLab System 100</td><td>Oxford Instruments</td><td></td><td>ICP IRE machine</td></tr><tr><td>UV curing system for nanoimprint fabrication</td><td></td><td></td><td>Not available on market</td></tr><tr><td>Ocean Optics HR-4000&amp;nbsp;</td><td>Ocean Optics</td><td>HR-4000</td><td>Spectrometer with normal detector</td></tr><tr><td>Lambda 950 UV / VIS</td><td>PerkinElmer</td><td></td><td>spectrometer with hemisphere intergration detector</td></tr><tr><td>JSM-7001F-LV</td><td>JEOL</td><td></td><td>Field emission SEM</td></tr><tr><td>DC magnetron sputtering machine</td><td></td><td></td><td>Equipment is in HP labs, who helped us to sputter the TiO&lt;sub&gt;2&lt;/sub&gt;</td></tr><tr><td>Metal e-beam evaporator</td><td>Temescal</td><td>BJD-1800</td><td></td></tr></tbody></table>

fabrication of high contrast gratings for the spectrum splitting dispersive element in a concentrated photovoltaic system

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve the solar conversion efficiency of a concentrated photovoltaic system. The proposed system will also lower the solar cell cost in the concentrated photovoltaic system by replacing the expensive tandem solar cells with the cost-effective single junction solar cells. The structures and the parameters of high contrast gratings for the dispersive elements were numerically optimized. The large-area fabrication of high contrast gratings was experimentally demonstrated using nanoimprint lithography and dry etching. The quality of grating material and the performance of the fabricated device were both experimentally characterized. By analyzing the measurement results, the possible side effects from the fabrication processes are discussed and several methods that have the potential to improve the fabrication processes are proposed, which can help to increase the optical efficiency of the fabricated devices.

图1示出了色散元件（多层高对比度光栅（HCG））的一个集中式光伏系统的实施。太阳光线首先由主反射镜反射并撞击反射色散元件，其中该光束被反射并分成不同波长的不同的频带上。每个频带将撞击在目标位置的太阳电池阵列的最佳吸收并转化成电力上。这里的关键系统是设计和实现色散元件，它是由HCG的多层的。 图2示出了用于在分散元件的每...

Watch this Scientific Journal Video about Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System at JoVE.com

Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System

The fabrication of high contrast gratings as the parallel spectrum splitting dispersive element in a concentrated photovoltaic system is demonstrated. Fabrication processes including nanoimprint lithography, TiO2 sputtering and reactive ion etching are described. Reflectance measurement results are used to characterize the optical performance.

制造高对比度光栅的频谱分割色散元件的聚光光伏系统

High contrast gratings are designed and fabricated and its application is proposed in a parallel spectrum splitting dispersive element that can improve ...

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10.7K 次观看.  University of Sothern California. The fabrication of high contrast gratings as the parallel spectrum splitting dispersive element in a concentrated photovoltaic system is demonstrated. Fabrication processes including nanoimprint lithography, TiO2 sputtering and reactive ion etching are described. Reflectance measurement results are used to characterize the optical performance. 

视频: Fabrication of High Contrast Gratings for the Spectrum Splitting Dispersive Element in a Concentrated Photovoltaic System

Polycrystalline Silicon Thin-film Solar cells with Plasmonic-enhanced Light-trapping

One of major approaches to cheaper solar cells is reducing the amount of semiconductor material used for their fabrication and making cells thinner. To compensate for lower light absorption such physically thin devices have to incorporate light-trapping which increases their optical thickness. Light scattering by textured surfaces is a common technique but it cannot be universally applied to all solar cell technologies. Some cells, for example those made of evaporated silicon, are planar as produced and they require an alternative light-trapping means suitable for planar devices. Metal nanoparticles formed on planar silicon cell surface and capable of light scattering due to surface plasmon resonance is an effective approach.
The paper presents a fabrication procedure of evaporated polycrystalline silicon solar cells with plasmonic light-trapping and demonstrates how the cell quantum efficiency improves due to presence of metal nanoparticles.
To fabricate the cells a film consisting of alternative boron and phosphorous doped silicon layers is deposited on glass substrate by electron beam evaporation. An Initially amorphous film is crystallised and electronic defects are mitigated by annealing and hydrogen passivation. Metal grid contacts are applied to the layers of opposite polarity to extract electricity generated by the cell. Typically, such a ~2 &mu;m thick cell has a short-circuit current density (Jsc) of 14-16 mA/cm2, which can be increased up to 17-18 mA/cm2 (~25% higher) after application of a simple diffuse back reflector made of a white paint.
To implement plasmonic light-trapping a silver nanoparticle array is formed on the metallised cell silicon surface. A precursor silver film is deposited on the cell by thermal evaporation and annealed at 23&deg;C to form silver nanoparticles. Nanoparticle size and coverage, which affect plasmonic light-scattering, can be tuned for enhanced cell performance by varying the precursor film thickness and its annealing conditions. An optimised nanoparticle array alone results in cell Jsc enhancement of about 28%, similar to the effect of the diffuse reflector. The photocurrent can be further increased by coating the nanoparticles by a low refractive index dielectric, like MgF2, and applying the diffused reflector. The complete plasmonic cell structure comprises the polycrystalline silicon film, a silver nanoparticle array, a layer of MgF2, and a diffuse reflector. The Jsc for such cell is 21-23 mA/cm2, up to 45% higher than Jsc of the original cell without light-trapping or ~25% higher than Jsc for the cell with the diffuse reflector only.
Introduction
Light-trapping in silicon solar cells is commonly achieved via light scattering at textured interfaces. Scattered light travels through a cell at oblique angles for a longer distance and when such angles exceed the critical angle at the cell interfaces the light is permanently trapped in the cell by total internal reflection (Animation 1: Light-trapping). Although this scheme works well for most solar cells, there are developing technologies where ultra-thin Si layers are produced planar (e.g. layer-transfer technologies and epitaxial c-Si layers) 1 and or when such layers are not compatible with textures substrates (e.g. evaporated silicon) 2. For such originally planar Si layer alternative light trapping approaches, such as diffuse white paint reflector 3, silicon plasma texturing 4 or high refractive index nanoparticle reflector 5 have been suggested.
Metal nanoparticles can effectively scatter incident light into a higher refractive index material, like silicon, due to the surface plasmon resonance effect 6. They also can be easily formed on the planar silicon cell surface thus offering a light-trapping approach alternative to texturing. For a nanoparticle located at the air-silicon interface the scattered light fraction coupled into silicon exceeds 95% and a large faction of that light is scattered at angles above critical providing nearly ideal light-trapping condition (Animation 2: Plasmons on NP). The resonance can be tuned to the wavelength region, which is most important for a particular cell material and design, by varying the nanoparticle average size, surface coverage and local dielectric environment 6,7. Theoretical design principles of plasmonic nanoparticle solar cells have been suggested 8. In practice, Ag nanoparticle array is an ideal light-trapping partner for poly-Si thin-film solar cells because most of these design principle are naturally met. The simplest way of forming nanoparticles by thermal annealing of a thin precursor Ag film results in a random array with a relatively wide size and shape distribution, which is particularly suitable for light-trapping because such an array has a wide resonance peak, covering the wavelength range of 700-900 nm, important for poly-Si solar cell performance. The nanoparticle array can only be located on the rear poly-Si cell surface thus avoiding destructive interference between incident and scattered light which occurs for front-located nanoparticles 9. Moreover, poly-Si thin-film cells do not requires a passivating layer and the flat base-shaped nanoparticles (that naturally result from thermal annealing of a metal film) can be directly placed on silicon further increases plasmonic scattering efficiency due to surface plasmon-polariton resonance 10.
The cell with the plasmonic nanoparticle array as described above can have a photocurrent about 28% higher than the original cell. However, the array still transmits a significant amount of light which escapes through the rear of the cell and does not contribute into the current. This loss can be mitigated by adding a rear reflector to allow catching transmitted light and re-directing it back to the cell. Providing sufficient distance between the reflector and the nanoparticles (a few hundred nanometers) the reflected light will then experience one more plasmonic scattering event while passing through the nanoparticle array on re-entering the cell and the reflector itself can be made diffuse - both effects further facilitating light scattering and hence light-trapping. Importantly, the Ag nanoparticles have to be encapsulated with an inert and low refractive index dielectric, like MgF2 or SiO2, from the rear reflector to avoid mechanical and chemical damage 7. Low refractive index for this cladding layer is required to maintain a high coupling fraction into silicon and larger scattering angles, which are ensured by the high optical contrast between the media on both sides of the nanoparticle, silicon and dielectric 6. The photocurrent of the plasmonic cell with the diffuse rear reflector can be up to 45% higher than the current of the original cell or up to 25% higher than the current of an equivalent cell with the diffuse reflector only.

Polycrystalline silicon thin-film solar cells on glass are fabricated by deposition of boron and phosphorous doped silicon layers followed by crystallisation, defect passivation and metallisation. Plasmonic light-trapping is introduced by forming Ag nanoparticles on the silicon cell surface capped with a diffused reflector resulting in ~45% photocurrent enhancement.

多晶硅薄膜太阳能电池电浆增强光捕获

One of major approaches to cheaper solar cells is reducing the amount of semiconductor material used for their fabrication and making cells thinner. To ...

科研

工程学

Harvesting Solar Energy by Means of Charge-Separating Nanocrystals and Their Solids

Conjoining different semiconductor materials in a single nano-composite provides synthetic means for the development of novel optoelectronic materials offering a superior control over the spatial distribution of charge carriers across material interfaces. As this study demonstrates, a combination of donor-acceptor nanocrystal (NC) domains in a single nanoparticle can lead to the realization of efficient photocatalytic1-5 materials, while a layered assembly of donor- and acceptor-like nanocrystals films gives rise to photovoltaic materials.
Initially the paper focuses on the synthesis of composite inorganic nanocrystals, comprising linearly stacked ZnSe, CdS, and Pt domains, which jointly promote photoinduced charge separation. These structures are used in aqueous solutions for the photocatalysis of water under solar radiation, resulting in the production of H2 gas. To enhance the photoinduced separation of charges, a nanorod morphology with a linear gradient originating from an intrinsic electric field is used5. The inter-domain energetics are then optimized to drive photogenerated electrons toward the Pt catalytic site while expelling the holes to the surface of ZnSe domains for sacrificial regeneration (via methanol). Here we show that the only efficient way to produce hydrogen is to use electron-donating ligands to passivate the surface states by tuning the energy level alignment at the semiconductor-ligand interface. Stable and efficient reduction of water is allowed by these ligands due to the fact that they fill vacancies in the valence band of the semiconductor domain, preventing energetic holes from degrading it. Specifically, we show that the energy of the hole is transferred to the ligand moiety, leaving the semiconductor domain functional. This enables us to return the entire nanocrystal-ligand system to a functional state, when the ligands are degraded, by simply adding fresh ligands to the system4.
To promote a photovoltaic charge separation, we use a composite two-layer solid of PbS and TiO2 films. In this configuration, photoinduced electrons are injected into TiO2 and are subsequently picked up by an FTO electrode, while holes are channeled to a Au electrode via PbS layer6. To develop the latter we introduce a Semiconductor Matrix Encapsulated Nanocrystal Arrays (SMENA) strategy, which allows bonding PbS NCs into the surrounding matrix of CdS semiconductor. As a result, fabricated solids exhibit excellent thermal stability, attributed to the heteroepitaxial structure of nanocrystal-matrix interfaces, and show compelling light-harvesting performance in prototype solar cells7.

A general strategy for the development of charge-separating semiconductor nanocrystal composites deployable for solar energy production is presented. We show that assembly of donor-acceptor nanocrystal domains in a single nanoparticle geometry gives rise to a photocatalytic function, while bulk-heterojunctions of donor-acceptor nanocrystal films can be used for photovoltaic energy conversion.

通过电荷分离纳米晶及其固体收获太阳能

Conjoining different semiconductor materials in a single nano-composite provides synthetic means for the development of novel optoelectronic materials ...

Using Neutron Spin Echo Resolved Grazing Incidence Scattering to Investigate Organic Solar Cell Materials

The spin echo resolved grazing incidence scattering (SERGIS) technique has been used to probe the length-scales associated with irregularly shaped crystallites. Neutrons are passed through two well defined regions of magnetic field; one before and one after the sample. The two magnetic field regions have opposite polarity and are tuned such that neutrons travelling through both regions, without being perturbed, will undergo the same number of precessions in opposing directions. In this case the neutron precession in the second arm is said to &#34;echo&#34; the first, and the original polarization of the beam is preserved. If the neutron interacts with a sample and scatters elastically the path through the second arm is not the same as the first and the original polarization is not recovered. Depolarization of the neutron beam is a highly sensitive probe at very small angles (&#60;50&#160;&#956;rad) but still allows a high intensity, divergent beam to be used. The decrease in polarization of the beam reflected from the sample as compared to that from the reference sample can be directly related to structure within the sample.
In comparison to scattering observed in neutron reflection measurements the SERGIS signals are often weak and are unlikely to be observed if the in-plane structures within the sample under investigation are dilute, disordered, small in size and polydisperse or the neutron scattering contrast is low. Therefore, good results will most likely be obtained using the SERGIS technique if the sample being measured consist of thin films on a flat substrate and contain scattering features that contains a high density of moderately sized features (30 nm to 5 &#181;m) which scatter neutrons strongly or the features are arranged on a lattice. An advantage of the SERGIS technique is that it can probe structures in the plane of the sample.

Progress has been made in utilizing spin echo resolved grazing incidence scattering (SERGIS) as a neutron scattering technique to probe the length-scales in irregular samples. Crystallites of [6,6]-phenyl-C61-butyric acid methyl ester have been probed using the SERGIS technique and the results confirmed by optical and atomic force microscopy.

使用中子自旋回声解决放牧发生率散射调查有机太阳能电池材料

The spin echo resolved grazing incidence scattering (SERGIS) technique has been used to probe the length-scales associated with irregularly shaped ...

Integrating a Triplet-triplet Annihilation Up-conversion System to Enhance Dye-sensitized Solar Cell Response to Sub-bandgap Light

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents and hence higher efficiencies. Photon up-conversion by way of triplet-triplet annihilation (TTA-UC) is an attractive technique for using these otherwise wasted low energy photons to produce photocurrent, while not interfering with the photoanodic performance in a deleterious manner. Further to this, TTA-UC has a number of features, distinct from other reported photon up-conversion technologies, which renders it particularly suitable for coupling with DSC technology. In this work, a proven high performance TTA-UC system, comprising a palladium porphyrin sensitizer and rubrene emitter, is combined with a high performance DSC (utilizing the organic dye D149) in an integrated device. The device shows an enhanced response to sub-bandgap light over the absorption range of the TTA-UC sub-unit resulting in the highest figure of merit for up-conversion assisted DSC performance to date.

An integrated device, incorporating a dye-sensitized solar cell and triplet-triplet annihilation up-conversion unit was produced, affording enhanced light harvesting, from a wider section of the solar spectrum. Under modest irradiation levels a significantly enhanced response to low energy photons was demonstrated, yielding a record figure of merit for dye-sensitized solar cells.

集成的三重态 - 三重态湮灭上转换系统，提高染料敏化太阳能电池的响应子带隙光

The poor response of dye-sensitized solar cells (DSCs) to red and infrared light is a significant impediment to the realization of higher photocurrents ...

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Here, we present a protocol to fabricate organic thin film solar cells using a mini-slot die coater and related in-line structure characterizations using synchrotron scattering techniques.

散装异质结太阳能电池的印刷和制作<em&gt;原位</em&gt;形态特征

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices ...

Fabrication of Fully Solution Processed Inorganic Nanocrystal Photovoltaic Devices

We demonstrate a method for the preparation of fully solution processed inorganic solar cells from a spin and spray coating deposition of nanocrystal inks. For the photoactive absorber layer, colloidal CdTe and CdSe nanocrystals (3-5 nm) are synthesized using an inert hot injection technique and cleaned with precipitations to remove excess starting reagents. Similarly, gold nanocrystals (3-5 nm) are synthesized under ambient conditions and dissolved in organic solvents. In addition, precursor solutions for transparent conductive indium tin oxide (ITO) films are prepared from solutions of indium and tin salts paired with a reactive oxidizer. Layer-by-layer, these solutions are deposited onto a glass substrate following annealing (200-400 &#176;C) to build the nanocrystal solar cell (glass/ITO/CdSe/CdTe/Au). Pre-annealing ligand exchange is required for CdSe and CdTe nanocrystals where films are dipped in NH4Cl:methanol to replace long-chain native ligands with small inorganic Cl- anions. NH4Cl(s) was found to act as a catalyst for the sintering reaction (as a non-toxic alternative to the conventional CdCl2(s) treatment) leading to grain growth (136&#177;39 nm) during heating. The thickness and roughness of the prepared films are characterized with SEM and optical profilometry. FTIR is used to determine the degree of ligand exchange prior to sintering, and XRD is used to verify the crystallinity and phase of each material. UV/Vis spectra show high visible light transmission through the ITO layer and a red shift in the absorbance of the cadmium chalcogenide nanocrystals after thermal annealing. Current-voltage curves of completed devices are measured under simulated one sun illumination. Small differences in deposition techniques and reagents employed during ligand exchange have been shown to have a profound influence on the device properties. Here, we examine the effects of chemical (sintering and ligand exchange agents) and physical treatments (solution concentration, spray-pressure, annealing time and annealing temperature) on photovoltaic device performance.

This protocol describes the synthesis and solution deposition of inorganic nanocrystals layer by layer to produce thin film electronics on non-conductive surfaces. Solvent-stabilized inks can produce complete photovoltaic devices on glass substrates via spin and spray coating following post-deposition ligand exchange and sintering.

全面解决方案处理的无机纳米晶体光伏器件的制造

We demonstrate a method for the preparation of fully solution processed inorganic solar cells from a spin and spray coating deposition of nanocrystal ...

Influence of Hybrid Perovskite Fabrication Methods on Film Formation, Electronic Structure, and Solar Cell Performance

Hybrid organic/inorganic halide perovskites have lately been a topic of great interest in the field of solar cell applications, with the potential to achieve device efficiencies exceeding other thin film device technologies. Yet, large variations in device efficiency and basic physical properties are reported. This is due to unintentional variations during film processing, which have not been sufficiently investigated so far. We therefore conducted an extensive study of the morphology and electronic structure of a large number of CH3NH3PbI3 perovskite where we show how the preparation method as well as the mixing ratio of educts methylammonium iodide and lead(II) iodide impact properties like film formation, crystal structure, density of states, energy levels, and ultimately the solar cell performance.

We present an extensive study on the effects of different fabrication methods for organic/inorganic perovskite thin films by comparing crystal structures, density of states, energy levels, and ultimately the solar cell performance.

上成膜钙钛矿型混合制造方法，电子结构和太阳能电池性能的影响

Hybrid organic/inorganic halide perovskites have lately been a topic of great interest in the field of solar cell applications, with the potential to ...

化学

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass (ADG) Fresnel Lens for Concentrating Photovoltaics

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is composed of two materials, a plastic and an elastomer, whose dispersion characteristics (refractive index variation with wavelength) are different. We first designed the lens geometry and then used ray-tracing simulation, based on the Monte Carlo method, to analyze its performance from the point of view of both optical efficiency and the maximum attainable concentration. Afterwards, ADG Fresnel lens prototypes were manufactured using a simple and reliable method. It consists of a prior injection of plastic parts and a consecutive lamination, together with the elastomer and a glass substrate to fabricate the parquet of ADG Fresnel lenses. The accuracy of the manufactured lens profile is examined using an optical microscope while its optical performance is evaluated using a solar simulator for concentrator photovoltaic systems. The simulator is composed of a xenon flash lamp whose emitted light is reflected by a parabolic mirror. The collimated light has a spectral distribution and an angular aperture similar to the real Sun. We were able to assess the optical performance of the ADG Fresnel lenses by taking photographs of the irradiance spot cast by the lens using a charge-coupled device (CCD) camera and measuring the photocurrent generated by several types of multi junction (MJ) solar cells, which have been previously characterized at a solar simulator for concentrator solar cells. These measurements have demonstrated the achromatic behavior of ADG Fresnel lenses and, as a consequence, the suitability of the modelling and manufacturing methods.

Indoor Experimental Assessment of the Efficiency and Irradiance Spot of the Achromatic Doublet on Glass ADG Fresnel Lens for Concentrating Photovoltaics

The achromatic doublet on glass (ADG) Fresnel lens makes use of two materials with differing dispersion to reduce chromatic aberration and increase attainable concentration. In this paper, a protocol for the complete characterization of the ADG Fresnel lens is presented.

玻璃 (ADG) 菲涅耳透镜对聚光光伏的效率和辐照点的室内实验评价

We present a method to characterize achromatic Fresnel lenses for photovoltaic applications. The achromatic doublet on glass (ADG) Fresnel lens is ...

Developing High Performance GaP/Si Heterojunction Solar Cells

To improve the efficiency of Si-based solar cells beyond their Shockley-Queisser limit, the optimal path is to integrate them with III-V-based solar cells. In this work, we present high performance GaP/Si heterojunction solar cells with a high Si minority-carrier lifetime and high crystal quality of epitaxial GaP layers. It is shown that by applying phosphorus (P)-diffusion layers into the Si substrate and a SiNx layer, the Si minority-carrier lifetime can be well-maintained during the GaP growth in the molecular beam epitaxy (MBE). By controlling the growth conditions, the high crystal quality of GaP was grown on the P-rich Si surface. The film quality is characterized by atomic force microscopy and high-resolution x-ray diffraction. In addition, MoOx was implemented as a hole-selective contact that led to a significant increase in the short-circuit current density. The achieved high device performance of the GaP/Si heterojunction solar cells establishes a path for further enhancement of the performance of Si-based photovoltaic devices.

Here, we present a protocol to develop high-performance GaP/Si heterojunction solar cells with a high Si minority-carrier lifetime.

研制高性能的 gap-硅异构太阳能电池

To improve the efficiency of Si-based solar cells beyond their Shockley-Queisser limit, the optimal path is to integrate them with III-V-based solar ...

In situ Grazing Incidence Small Angle X-ray Scattering on Roll-To-Roll Coating of Organic Solar Cells with Laboratory X-ray Instrumentation

We present an in-house, in situ Grazing Incidence Small Angle X-ray Scattering (GISAXS) experiment, developed to probe the drying kinetics of roll-to-roll slot-die coating of the active layer in organic photovoltaics (OPVs), during deposition. For this demonstration, the focus is on the combination of P3HT:O-IDTBR and P3HT:EH-IDTBR, which have different drying kinetics and device performance, despite their chemical structure only varying slightly by the sidechain of the small molecule acceptor. This article provides a step-by-step guide to perform an in situ GISAXS experiment and demonstrates how to analyze and interpret the results. Usually, performing this type of in situ X-ray experiments to investigate the drying kinetics of the active layer in OPVs relies on access to synchrotrons. However, by using and further developing the method described in this paper, it is possible to perform experiments with a coarse temporal and spatial resolution, on a day-to-day basis to gain fundamental insight in the morphology of drying inks.

This paper is a demonstration and a guideline to perform and analyze in-house (with a laboratory X-ray instrument) in situ GISAXS experiments of drying inks on roll-to-roll slot-die coated, non-fullerene organic photovoltaics.

通过实验室X射线仪器对有机太阳能电池的滚滚涂层进行现场放牧小角度X射线散射

We present an in-house, in situ Grazing Incidence Small Angle X-ray Scattering (GISAXS) experiment, developed to probe the drying kinetics of roll-to-roll ...