利用双异质结J-V特性分析镁离子对钙钛矿太阳能电池的影响

尽管MAPbI3钙钛矿太阳能电池的效率已经达到很高的水平,但是多晶钙钛矿材料的晶界会俘获自由载流子,影响效率的进一步提升.本文研究在MAPbI3钙钛矿中添加适量镁(Mg)离子钝化晶界,来提高钙钛矿太阳能电池的性能,并采用双异质结等效电路分析镁离子对钙钛矿太阳能电池中载流子复合和输运特性的影响.研究结果显示适量镁离子掺入...     

利用高度稳定的发光薄膜提高多晶硅太阳能电池的光伏效率（英文）

硅基太阳能电池已经主导了整个光伏市场,但是仍然面临着光电转化效率低的问题,其中部分原因是其对紫外线的利用率较低.稀土铕配合物能够将紫外光转化为可见光,有望提高硅基太阳能电池的光电转化效率.然而,这类配合物较低的稳定性限制了它们的实际应用.本文中,我们制备了一种高度稳定的EVA/Eu(ND)4-CTAC发光薄膜,将其覆盖在大尺寸的多晶硅太阳能电池表面(110 cm^2)可以使得光电转化效率从15.06%提高到15.57%.在500 h的加速老化实验中荧光性能几乎没有下降,证明了发光薄膜的超强稳定性.在如此大的有效面积上,发光薄膜使硅基太阳能电池的转换效率提高0.51%的绝对值,同时实现超高的稳定性,说明该发光膜在光伏工业上具有广阔的应用前景.     

稀土掺杂上转换发光纳米材料在有机光伏器件中的应用进展

稀土掺杂上转换发光纳米材料(UCNPs)是一种在近红外光激发下发出可见光的纳米材料,将UCNPs掺入有机光伏电池中,可以扩大有机光伏电池对太阳光谱的响应范围,提高有机光伏电池的光电转换效率。综述了UCNPs在染料敏化太阳能电池、聚合物太阳能电池中的应用进展,展望了该材料未来的研究方向。     

多层减反射膜对PERC太阳电池性能的影响

优化晶体硅材料的光学特性,可有效提高晶体硅太阳能电池的光电转换效率.采用等离子体增强化学气相沉积(PECVD)法,在钝化发射极和背表面太阳电池(PERC)上成功制备出叠层结构的多层减反射薄膜提升硅材料的光学特性.研究结果表明,正面使用二氧化硅(SiO2)、氮化硅(SiNx)、氮氧化硅作为器件的叠层介质膜,将SiO2/S...     

杂化聚酰亚胺薄膜无机相形貌和介电性能研究

采用溶胶-凝胶法制备纳米二氧化硅及氧化铝溶胶,将其掺入聚酰胺酸溶液中,制得聚酰亚胺/二氧化硅-氧化铝杂化薄膜,利用原子力显微镜对杂化薄膜的无机相微观形貌进行表征,用精密阻抗分析仪测试杂化膜介电性能.研究表明:掺入无机组分含量均为4%时,随着掺入二氧化硅所占比例的增大,无机纳米粒子的平均粒径增加,当其与氧化铝质量比为8:1时无机相呈网络状,与聚酰亚胺基体界面模糊;掺入无机组分对杂化薄膜的介电性能产生影响,介电常数ε和介电损耗tgδ随频率增加而减小,在相同频率下随掺入二氧化硅所占比例增大,介电常数ε和介电损耗tgδ增大.     

宽波段减反膜实现23.9%效率的平面异质结构钙钛矿太阳能电池

虽然钙钛矿太阳能电池效率的发展令人鼓舞,但是由于光反射造成的器件基底界面的光子损失等问题仍然没有解决.光管理是降低反射损失并提高器件效率的有效途径.因此,我们设计了双层减反膜以涂敷在(FAPbI₃)_x(MAPbBr₃)_1-x钙钛矿太阳能电池的玻璃基底外侧,以期达到增加光吸收和提高器件效率的目的.该研究中的减反膜底层由硅聚合物构成,上层由氟代硅聚合物和六甲基二硅氧烷/介孔二氧化硅纳米粒子复合而成.通过精确调控上下层的折射率及厚度,我们在宽波段范围内实现了玻璃基底透过率从最高约90%显著提升到95%.在电池器件的玻璃基底外侧溶液涂膜制备减反膜后,(FAPbI₃)_x(MAPbBr₃)_1-x钙钛矿太阳能电池在保持填充因子和开路电压不变的情况下,短路电流和效率分别从25.5 mA cm^-2和22.7%提高到26.5 mA cm^-2和23.9%.本研究提出了一种简单、高效的通过双层减反膜的光管理提高太阳能电池效率的方法,且此方法可拓展到其他类型太阳能电池体系.     

纳米二氧化硅对苯丙共聚物/水泥复合胶凝材料凝结硬化的影响

采用纳米二氧化硅作为调凝物质以期解决苯丙共聚物/水泥复合胶凝材料凝结硬化慢的问题。通过测定纳米二氧化硅改性苯丙共聚物/水泥复合胶凝材料的凝结时间及早期强度,分析纳米二氧化硅对复合胶凝材料凝结硬化过程的影响;采用等温量热法测定纳米二氧化硅改性苯丙共聚物/水泥的水化热,并采用X射线衍射仪对其水化产物进行表征;综合以上分析结果探讨纳米二氧化硅的作用机制。结果表明:掺入二氧化硅能有效促进复合胶凝材料的凝结硬化,二氧化硅掺量为1. 25%时促进作用最为显著;掺入纳米二氧化硅可促进铝酸三钙和硅酸三钙的水化,加快钙钒石和氢氧化钙的生成,缩短复合胶凝材料的水化诱导期和加速期,加快水泥水化进程,从而缩短凝结时间,提高早期强度。     

稀土发光材料在染料敏化太阳能电池中的研究进展

染料敏化太阳能电池(DSSCs)由于工艺简单、价格便宜、转换效率高等优点而备受关注.其中起负载敏化剂以及收集和传输电子作用的光阳极是关系到电池性能的重要部件.介绍了染料敏化太阳能电池的基本结构和工作原理,综述了优化染料敏化太阳能电池结构的研究现状;重点阐述了稀土发光材料改性二氧化钛提高光电转换效率的研究进展;指出稀土发光材料改性二氧化钛光阳极是提高染料电池光电转换效率的有效途径,也是未来的主要发展方向.     

聚合物太阳能电池光敏层材料及形貌的研究进展

聚合物太阳能电池由于质量轻、成本低、柔韧性好及制备工艺简便等优点而具有巨大的潜在应用价值,是太阳能电池发展的新方向.但是聚合物太阳能电池的能量转换效率较低,达不到商业化应用的要求,如何提高电池效率仍是目前研究的重点.聚合物材料和光敏层的形貌是影响太阳能电池性能的两大要素,从机理方面分析了限制太阳能电池效率的一些因素,介绍了聚合物材料的新进展,探讨了聚合物材料设计的原则及方法,着重探讨了形貌对太阳能电池性能的影响以及改进形貌的方法及其理论基础,并展望了聚合物太阳能电池未来的发展趋势.     

纳米改性再生骨料混凝土单轴受压疲劳性能

采用纳米二氧化硅对再生骨料混凝土(RAC)进行改性,开展了不同再生骨料取代率及纳米改性后的再生骨料混凝土单轴受压疲劳试验,研究其疲劳寿命、疲劳方程、疲劳变形规律及疲劳剩余强度,并利用纳米压痕试验从细观层面上分析探讨了纳米二氧化硅对再生骨料混凝土多重界面过渡区的影响。结果表明:再生骨料混凝土疲劳寿命均较好地服从两参数威布尔概率分布。50%保证率、0.75应力水平下,再生骨料混凝土的疲劳寿命比普通混凝土降低了25.8%,掺入纳米二氧化硅可显著提高再生骨料混凝土的疲劳寿命。对比应变演化曲线和剩余强度模型,纳米二氧化硅改性后的再生骨料混凝土,剩余强度衰减非线性规律明显。纳米二氧化硅的掺入提高了再生骨料混凝土多重界面过渡区的压痕模量,改善了再生骨料混凝土的疲劳性能。     

Pt/Y<Subscript>2</Subscript>O<Subscript>3</Subscript>:Eu<Superscript>3+</Superscript> composite nanotubes: Enhanced photoluminescence and application in dye-sensitized solar cells

Y(OH)3:Eu3+ nanotubes were synthesized using a facile hydrothermal method,and then,Pt particles were grown on the surface of the nanotubes using a combination of vacuum extraction and annealing.The resulting Pt/Y2O3∶Eu3+ composite nanotubes not only exhibited enhanced red luminescence under 255-or 468-nm excitation but could also be used to improve the efficiency of dyesensitized solar cells,resulting in an efficiency of 8.33％,which represents a significant enhancement of 11.96％ compared with a solar cell without the composite nanotubes.Electrochemical impedance spectroscopy results indicated that the interfacial resistance of the TiO2-dye|I3-/I-electrolyte interface of the TiO2-Pt/Y2O3:Eu3+ composite cell was much smaller than that of a pure TiO2 cell.In addition,the TiO2-Pt/Y2O3:Eu3+ composite cell exhibited a shorter electron transport time and longer electron recombination time than the pure TiO2 cell.     

Facile fabrication of Si nanowire arrays for solar cell application

Large-area Si nanowire arrays have been fabricated on phosphorus doped Si surface by a facile silver-catalyzed chemical etching process. The solar cell incorporated with Si nanowire arrays shows a power conversion efficiency of 6.69% with an open circuit voltage of 558 mV and a short circuit current density of 25.13 mA/cm2 under AM 1.5 G illumination without using any extra antireflection layer and surface passivation technique. The high power conversion efficiency of Si nanowires based-solar cell is attributed to the low reflectance loss of Si nanowire arrays for incident sunlight. Optimization of electrical contact and phosphorus diffusion process will be critical to improve the performance of Si nanowires-based solar cell in the future.     

Nanostructure formation and passivation of large-area black silicon for solar cell applications

Nanoscale textured silicon and its passivation are explored by simple low-cost metal-assisted chemical etching and thermal oxidation, and large-area black silicon was fabricated both on single-crystalline Si and multicrystalline Si for solar cell applications. When the Si surface was etched by HF/AgNO(3) solution for 4 or 5 min, nanopores formed in the Si surface, 50-100 nm in diameter and 200-300 nm deep. The nanoscale textured silicon surface turns into an effective medium with a gradually varying refractive index, which leads to the low reflectivity and black appearance of the samples. Mean reflectance was reduced to as low as 2% for crystalline Si and 4% for multicrystalline Si from 300 to 1000 nm, with no antireflective (AR) coating. A black-etched multicrystalline-Si of 156 mm × 156 mm was used to fabricate a primary solar cell with no surface passivation or AR coating. Its conversion efficiency (η) was 11.5%. The cell conversion efficiency was increased greatly by using surface passivation process, which proved very useful in suppressing excess carrier recombination on the nanostructured surface. Finally, a black m-Si cell with efficiency of 15.8% was achieved by using SiO(2) and SiN(X) bilayer passivation structure, indicating that passivation plays a key role in large-scale manufacture of black silicon solar cells.     

湿法腐蚀硅片并生长氧化锌纳米棒作为太阳能电池减反层研究

在硅基太阳能电池表面制备减反层可以有效降低硅表面的反射率, 提高吸收率, 从而提高硅基太阳能电池的光电转换效率。本研究利用四甲基氢氧化铵(Tetramethyl Ammonium Hydroxide TMAH)溶液对(100)单晶硅进行各向异性腐蚀, 在表面腐蚀出金字塔结构, 得到了最低为6%左右的反射率。然后采用水热法在该衬底生长氧化锌纳米棒, 得到了最低小于3%的反射率, 比单采用腐蚀或者ZnO纳米棒生长的硅表面的反射率更低。这种减反方法工艺简单、高效, 有望得到应用。     

Luminescence efficiency enhancement of BaZr(BO3)2:Eu with Si or Al addition

Si4+ and Al3+ doped BaZr(BO3)2:Eu phosphors were prepared by solidstate reaction. BaZr(BO3)2:Eu3+, BaZr(BO3)2:Eu3+, Si4+ and BaZr(BO3)2:Eu3+, Al3+ were characterized by X-ray diffraction spectra (XRD) and photoluminescence spectra. After codoped with Si or Al, the charge-transfer state (CTS) band of Eu3+-O(2-) shows blue shift accompanied by increasing intensity due to shorter ionic radius and stronger electro negativity of Si or Al compared with Zr4+. The high value of asymmetric ratio R(2-1) and omega2 of BaZr(BO3)2:Eu3+ with Si or Al codoping indicates a less symmetrical local structure of Eu3+. This implies that the quantum efficiencies of the 5D0 level of these complexes can be enhanced by doping with Si and Al respectively. Calculation of the Judd-Ofelt parameters of Eu3+ under different crystal fields gives similar results.     

一种新型的ITO／TiSi2双层前电极a—Si：H太阳电池

如何提高ａ－Ｓｉ：Ｈ太阳电池的转变效率和稳定性一直是人们最关心的问题。本实验采用一种新型的Ｇｌａｓｓ／ＩＴＯ／ＴｉＳｉ２／ｐｉｎ／Ａｌ双层前电极ａ－Ｓｉ：Ｈ太阳电池,通过老化处理后发现,这种新型电池较之常规电池主要参数均改善,电池的稳定性明显提高。     

面向太阳光全光谱应用铒掺杂硫卤玻璃上转换发光特性研究

使用熔融淬冷法制备了Er³⁺掺杂Ge-Ga-S-CsBr硫卤玻璃, 研究了其在1550 nm激光激发下的上转换发光特性, 观察到强的波长中心位于525和545 nm绿色发光及弱的中心波长位于660 nm红色发光, 也观察到了中心波长分别位于810和980 nm的红外上转换发光。基于泵探光功率关系和能级寿命测试研究了发光机理, 发现中间态能级寿命的延长是上转换发光效率增强的根本原因。使用全光谱光源测试了Si太阳能效率, 当使用上转换发光层时, 太阳能电池平均效率从7.28%上升至7.32%。结果显示所探索的稀土掺杂硫卤玻璃有望应用于硅太阳能电池效率增强领域。     

Development of new materials for solar cells in Nagoya Institute of Technology

Solar cells with high efficiency and low price have long been desired, however, the commercially available solar cells are still expensive and the efficiencies of them are not high enough yet. A tandem solar cell was fabricated to develop a high-efficiency solar cell, and amorphous carbon solar cells were fabricated to develop a low-price solar cell.An AlGaAs/Si tandem solar cell was successfully fabricated by heteroepitaxial growth of AlGaAs on Si substrate. At first, a p–n junction was formed in Si substrate by the impurity diffusion method. Then, an AlGaAs p–n junction was grown by MOCVD. Since the AlGaAs p–n junction has a graded band gap emitter, the photo-excited minority carriers can be collected efficiently. The energy conversion efficiency of AlGaAs/Si tandem solar cell was 21.4% (AM0) in spite of large lattice mismatch and difference in thermal expansion coefficients between AlGaAs and Si.Solar cells were fabricated by using amorphous carbon films deposited by Ion Beam Sputtering and Pulse Laser Deposition (PLD). The highest efficiency of 1.82% (AM0) was attained with a-C(IBS)/p-C(pyrolysis)/p-Si structure. Solar cells using a-C:H were also fabricated by PLD and Plasma CVD, and the efficiencies of them were 2.1% (AM1.5) and 0.04% (AM0), respectively.Other research activities on solar cells in Nagoya Institute of Technology are briefly mentioned.     

Fabrication and characteristics of n-Si/c-Si/p-Si heterojunction solar cells using hot-wire CVD

A double-side (bifacial) heterojunction (HJ) Si solar cell was fabricated using hot-wire chemical vapor deposition. The properties of n-type, intrinsic and p-type Si films were investigated. In these devices, the doped microcrystalline Si layers (n-type Si for emitter and p-type Si for back contact) are combined with and without a thin intrinsic amorphous Si buffer layer. The maximum temperature during the whole fabrication process was kept below 150 °C. The influence of hydrogen pre-treatment and n-Si emitter thickness on performance of solar cells have been studied. The best bifacial Si HJ solar cell (1 cm² sample) with an intrinsic layer yielded an active area conversion efficiency of 16.4% with an open circuit voltage of 0.645 V, short circuit current of 34.8 mA/cm² and fill factor of 0.73.     

The effect of SiO2 on TiO2 up-conversion photoluminescence film

In order to increase the photoelectric conversion efficiency of silicon solar cell, the up-conversion film has been tried to enhance the response of the solar cells to the infrared band. Yb³⁺, Er³⁺ co-doped SiO₂/TiO₂ composite films with different Ti/Si molar ratio were deposited on the glass substrate with sol–gel method and spin-coating technique. The effect of different molar ratio of Ti/Si on the film’s morphology and optical properties was investigated. The morphology, the absorption spectra and photoluminescence (PL) spectra of the film were tested and analyzed. After the film was annealed at 900 °C, the XRD diffraction pattern indicated that rare earths ions have evenly dispersed into the matrix lattice. The FT-IR showed that Si ions entered into the lattice of titanium dioxide, and the Ti–O–Si bonds came into being. When the film pumped with a laser of 980 nm, there were a dominant red emission and several weak green peaks. In addition, with the increase of the mole ratio of Si/Ti, the intensity of the film’s up-conversion luminescence increases at first and then decreases. When the molar ratio of Si/Ti is 1/8, the sample had the highest intensity of up-conversion luminescence.