KCl浓度对电沉积ZnO量子点敏化太阳能电池光电性能的影响

文章采用恒电位沉积法在导电玻璃上制备了ZnO薄膜,研究了沉积液中KCl浓度对ZnO薄膜结构的影响,将制备的ZnO薄膜应用于量子点敏化太阳能电池(QDSCs)的光阳极,而后分析了该太阳能电池的光电转换效率。文章还利用X射线衍射(XRD),以及扫描电子显微镜(SEM),表征ZnO薄膜的结构和形貌,以紫外-可见吸收光谱(UV-Vis)表征量子点敏化前后光阳极的光吸收特性,利用电化学工作站测试不同形貌ZnO-CdS太阳能电池的光电转换特性。分析结果表明:当KCl浓度为0.075 mol/L时,ZnO薄膜呈现出均匀多孔的纳米片结构,以该ZnO薄膜为光阳极的QDSC的开路电压为0.35 V,短路电流密度为3.17 mA/cm~2,光电转换效率为0.36%;与未添加KCl的ZnO薄膜相比,多孔片状ZnO薄膜的活性位点能够与电解液充分接触,这样提高了光阳极内光生电子的注入效率,从而使太阳能电池具有更高的的光电转换效率。     

TiO2相结纳米棒制备及其光催化深度脱除烟气汞的实验研究

采用溶剂热法制备了不同形貌和不同晶相掺杂的TiO2相结纳米棒,研究不同物质的量比下TiO2的形貌及相结对光催化氧化脱汞性能的影响.结果 表明:TB、ET、HAc与LiAc物质的量比为1∶20∶20∶5时,TiO2纳米棒的性能最佳,光响应范围可扩展到可见光;在可见光下光催化脱汞效率达到44.7％,且光催化剂的稳定性良好.     

全角度陷光的微-纳复合绒面单晶PERC太阳电池

采用银金属催化化学腐蚀（Ag-MCCE）技术在碱腐蚀的金字塔微米初级绒面结构上制备均匀的纳米次级绒面结构,并研究银纳米颗粒在微米金字塔表面的附着特性及其对纳米结构均匀性和电池性能的影响。结果表明,通过添加聚乙烯吡咯烷酮（PVP）可改善银纳米颗粒在微米金字塔表面的附着均匀性,制备的纳米结构在微米金字塔结构表面分布均匀,且便于后道SiN_x的钝化;制得的单晶PERC电池平均效率达到22.22%,较未改善的对比组提升0.46%;独特的微-纳复合绒面（NOM-texture）可实现单晶太阳电池的全角度陷光,兼顾新型光伏屋顶等光伏建筑一体化（BIPV）场合对电池高转换效率和准全向外观的双重要求。     

水热法制备TiO2纳米晶胶体及其在DSSC电池中的应用

采用钛酸异丙酯作前驱体，利用水热法制备了TiO2纳米溶胶溶液。以此制备了染料敏化太阳能电池的光阳极并组装电池。对产物采用激光粒度仪（HPPS）、X射线衍射（XRD）、扫描电镜（SEM）等进行表征。XRD显示了TiO2纳米颗粒为纯锐钛矿结构，SEM观察薄膜电极呈多孔结构。表征电池的光电化学性能，所制备的TiO2纳米晶薄膜的光电转换效率达到3．03％。     

钙钛矿敏化太阳电池制备工艺的优化研究

近年来,有机金属卤化物钙钛矿太阳电池因制备条件温和、光吸收强、能耗低、光电转化效率高等优点成为备受瞩目的研究热点。本文采用一步法制备钙钛矿材料甲胺碘化铅（CH3NH3PbI3）,并以廉价的聚（3-己基噻吩） （P3HT）为空穴传输材料在大气环境下制备钙钛矿敏化太阳电池。其中,通过调控TiO2浆料与松油醇、乙基纤维素的配比,分别制备具有250 nm、600 nm和1 000 nm三种不同厚度的TiO2纳米颗粒多孔薄膜光阳极,并系统考察钙钛矿前驱体溶液旋涂量对敏化电极结构形貌及光吸收性能的影响。太阳电池光电特性测试结果表明：当TiO2多孔层厚度为600 nm、钙钛矿前驱体溶液的旋涂量为40 μl时,CH3NH3PbI3能够较为完全地覆盖在多孔TiO2的表面,且钙钛矿材料的晶粒尺寸合适,TiO2孔道结构未被堵塞,有利于空穴导体的填充以及空穴的转移与传输,优化后的太阳电池光电转化效率达到5.17%。     

ZnO薄膜对CIGS太阳电池性能的影响

采用交流磁控溅射制备高阻ZnO和直流溅射ZnO：A1薄膜,研究几种溅射工艺条件与ZnO薄膜性能关系以及对铜铟镓硒(CIGS)光伏电池的影响。通过不同的工艺参数改变控制,得到了性能优良的ZnO薄膜,同时表明电池窗口层ZnO薄膜工艺参数对铜铟硒电池性能影响至关重要。尤其是ZnO薄膜的电阻率和迁移率,这两项指标的优化可以使电池的填充因子有10％以上的提高。不论是高阻ZnO还是低阻ZnO薄膜对电池的填充因子都有着重要的影响,采用优化工艺所制备的C1GS光伏电池窗口层ZnO薄膜以后,目前研制的电池转换效率已达到12．1％。     

染料敏化太阳电池中TiO_2薄膜微结构相关动力学研究

采用溶胶-凝胶法制备尺寸大小20nm和300nm的两种TiO2颗粒,二者以不同比例掺杂制备纳米多孔薄膜并应用于染料敏化太阳电池(DSC)中。采用强度调制光电流谱(IMPS)和强度调制光电压谱(IMVS)技术研究薄膜微结构变化对电子传输动力学过程的影响,进而分析大颗粒掺杂对电池性能影响的内在原因。结果表明,TiO2大颗粒作为光散射中心使光程增加可有效增大光强,但掺杂比例与染料吸附量存在竞争进而影响光吸收,研究表明:掺杂20wt%大颗粒纳米薄膜制备的DSC具有最佳性能,相比未掺杂的DSC,掺杂20wt%大颗粒的DSC短路电流Jsc从10.99mA/cm2增加到12.04mA/cm2,光电转换效率η增大8.2%。随TiO2大颗粒掺杂比例增大,电子传输时间τd减小。     

CdS量子点敏化TiO_2纳米颗粒多孔薄膜太阳能电池性能研究

以CdS量子点敏化TiO2纳米颗粒多孔薄膜为光阳极,与多硫电解液和Pt对电极组装太阳能电池,研究了光阳极厚度和敏化周期对光伏性能的影响。结果表明,TiO2纳米颗粒多孔薄膜的最佳厚度为14μm,最佳CdS量子点敏化周期为20,由此得到的太阳能电池的短路电流密度J sc、光电转换效率η和量子效率分别为4.51 mA/cm2、0.76%和69%。在光阳极中采用TiO2纳米颗粒/TiO2纳米线多孔薄膜双层工作电极,TiO2纳米线散射层增加了对入射光的利用率,使电池在可见光波段的量子效率增加,从而使电池的短路电流密度J sc和光电转换效率分别比原来提高了11.6%和10.5%。     

高效率Ⅱ-Ⅵ族(CdS,CdSe,CdTe)量子点敏化太阳电池

简单总结了笔者研究组近三年在量子点敏化太阳电池方面的研究工作.通过发展一些简单可控的合成方法制备了一系列Ⅱ-Ⅵ族量子点敏化的高效率太阳电池.利用连接剂辅助化学浴沉积法,以巯基乙酸为连接剂一步水热制备了单分散CdTe/CdS或CdTe/CdS核壳结构量子点以及量子点敏化的TiO2电极,并分别获得了最高3.80％(CdTe/CdS)和2.83％(CdSe/CdS)的光电转换效率;利用旋涂法在氧化锌纳米线阵列表面依次沉积了CdS/CdSe量子点,并取得了3.45％的光电转换效率;首次利用原位电沉积法在由纳米棒和纳米颗粒共同组成的分等级TiO2微米球电极上直接沉积CdS及CdSe量子点,取得了4.8％的光电转换效率,并用强度调制光电流/光电压谱(IMPS/IMVS)对CdS、CdSe量子点敏化电池和CdS/CdSe量子点共敏化电池进行了动力学研究,该型电池的电子收集效率高达98％.     

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.     

CdS量子点敏化TiO2纳米线束阵列太阳能电池的研究

采用水热合成技术,以盐酸、去离子水和酞酸丁酯为反应前驱物,在透明导电玻璃衬底(FTO)上生长TiO2纳米线束阵列,以化学浴沉积技术制备CdS量子点敏化TiO2纳米线束阵列光阳极。研究了CdS量子点敏化的循环周期对太阳能电池的光伏性能、单色光光子-电子转换效率、静态和动态光电流的特性的影响规律。结果表明:CdS量子点的大小和密度随着敏化循环周期的增加而增加,当敏化循环的周期为15次时,单色光光子-电子转换效率最高,电池的短路电流密度为0.61 mA/cm2,开路电压为0.65 V,填充因子为0.50,光电转换效率为0.20%。通过强度调制的光电流谱分析,得到光生电子在光阳极中的扩散系数为3.2×10-6cm2/s,传输时间为2.1×10-2s。     

Spontaneous formation of nanoripples on the surface of ZnO thin films as hole-blocking layer of inverted organic solar cells

A simple method for spontaneous formation of nanoripples on ZnO thin films was developed, and these nanostructured ZnO films were used as hole-blocking layer in inverted organic solar cells. Moreover, the size (height) of nanoripples on ZnO surface could be controlled in the range of several tens of nanometers. Among various ZnO films, surface structures with ∼70 nm-high nanoripples resulted in the best photovoltaic performance of the organic solar cell consisting of a stack of indium tin oxide/ZnO/ regioregular poly (3-hexyl thiophene), phenyl-C₆₁-butyric acid methyl ester/Ag. The power conversion efficiency of inverted organic solar cells consisting of with 70 nm-high ZnO nanoripples (∼3.2%) was higher than that of a relatively flat ZnO surface by a factor of ∼2. Existence of nanoripples on ZnO results in a higher contact area between ZnO and active layer, leading to an enhanced photovoltaic performance.     

Performance of double junction a-Si solar cells by using ZnO:Al films with different electrical and optical properties at the n/metal interface

High-quality ZnO:Al films have been prepared by using RF-magnetron-sputtering method with resistivity ranging from 10⁻¹ to 10⁻⁴ Ω cm and transmittance above 90% in visible region. We have fabricated small area (1 cm²) double junction (a-Si/a-Si) solar cells using ZnO/Al and ZnO/Ag as back contact. The conversion efficiency of double junction a-Si solar cell increases from 9.9% to 10.9% by using ZnO/Al back contact and to 11.4% by using ZnO/Ag as back contact. Effect of variation of thickness of i-layer on performance of the cell has also been studied.     

Effect of microfluidic electrolyte on the photovoltaic performance of ZnO-nanowire-based dye-sensitised solar cells

ZnO-nanowire-based dye-sensitised solar cells (DSSCs) were prepared to investigate the effect of microfluidic electrolyte on the photovoltaic performance of solar cells. At first, long and well-aligned ZnO nanowires were synthesised on FTO substrate via the improved hydrothermal method. The structure and crystallinity properties of ZnO nanowires were characterised by using SEM, TEM and XRD. The photovoltaic characteristics of the assembled DSSCs were measured under various flowrates of microfluidic electrolyte. The results showed that variations of the microfluidic electrolyte had little effect on the fill factor of the cells. However, the photocurrent and photovoltage of the solar cells exhibited systematic changes with the decrease of microfluidic electrolyte: the short-circuited current of the DSSCs decreased while the open-circuit voltage increased. The phenomenon could remain in some extent after cessation of injecting the electrolyte within a short time. The possible influencing mechanism of the microfluidic electrolyte on the photovoltaic performance was discussed.     

Dye-sensitized solar cells based on anatase TiO2 hollow spheres/carbon nanotube composite films

Dye-sensitized solar cells (DSSCs) based on anatase TiO₂ hollow spheres (TiO2HS)/multi-walled carbon nanotubes (CNT) nanocomposite films are prepared by a directly mechanical mixing and doctor blade method. The prepared samples are characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, UV-vis absorption spectroscopy and N₂ adsorption-desorption isotherms. The photoelectric conversion performances of the DSSCs based on TiO2HS/CNT composite film electrodes are also compared with commercial-grade Degussa P25 TiO₂ nanoparticles (P25)/CNT composite solar cells at the same film thickness. The results indicate that the photoelectric conversion efficiencies (η) of the TiO2HS/CNT composite DSSCs are dependent on CNT loading in the electrodes. A small amount of CNT clearly enhances DSSC efficiency, while excessive CNT loading significantly lowers their performance. The former is because CNT enhance the transport of electrons from the films to FTO substrates. The latter is due to high CNT loading shielding the visible light from being adsorbed by dyes.     

Development of highly efficient thin film silicon solar cells on texture-etched zinc oxide-coated glass substrates

ZnO films prepared by magnetron sputtering on glass substrates and textured by post-deposition chemical etching are applied as substrates for p–i–n solar cells. Using both rf and dc sputtering, similar surface textures can be achieved upon etching. Excellent light trapping is demonstrated by high quantum efficiencies at long wavelengths for microcrystalline silicon solar cells. Applying an optimized microcrystalline/amorphous p-layer design, stacked solar cells with amorphous silicon top cells yield similarly high stabilized efficiencies on ZnO as on state-of-the-art SnO₂ (9.2% for a-Si/a-Si). The efficiencies are significantly higher than on SnO₂-coated float glass as used for module production.     

Influence of Na on the properties of Cu-rich prepared CuInS2 thin films and the performance of corresponding CuInS2/CdS/ZnO solar cells

Using different glass substrate types the Na content in sequentially and Cu-rich prepared CuInS₂ films and corresponding CuInS₂/CdS/ZnO thin-film solar cells is varied. The purpose was to investigate the influence of different Na concentrations on absorbers and devices. While the morphology of the absorbers seems not to be affected by this variation, corresponding PL spectra differ significantly. The properties of the solar cells, however, show no dependence on the Na concentration. This implies that even though the defect chemistry of CuInS₂, sequentially prepared under Cu excess, is changed by the presence of Na this influence has no impact on properties of corresponding solar cells.     

Photovoltage enhancement of dye sensitised solar cells by using ZnO modified TiO2 electrode

Abstract

A ZnO modified TiO₂ (ZnO/TiO₂) film was prepared by immersing TiO₂ electrodes in Zn(Ac)₂ aqueous solution. The open circuit voltage of a dye sensitised solar cell (DSSC) with the ZnO/TiO2 film electrode has a dramatic enhancement, compared to the DSSC with the TiO₂ film electrode. However, the short circuit current density of the DSSC with the ZnO/TiO₂ film electrode is lower than that with TiO₂ electrode. The film electrodes were characterised by SEM, EDX and UV-vis, and the photoelectric performance of DSSCs were measured. The photovoltage enhancement is attributed to the formation of a flat-band potential energy barrier by ZnO at TiO₂/electrolyte interface. The decline of the photocurrent with ZnO/TiO₂ film electrode is due to poor dye absorption on larger particles of ZnO.     

Preparation and characterization of nano-scale ZnO as a buffer layer for inkjet printing of silver cathode in polymer solar cells

Less-populated and well-isolated ZnO nanorods were prepared from a simple solution method by using polyethylene glycol (PEG) surfactant molecules. The structural and morphological information provided by X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM) demonstrated the high purity of the ZnO nanorods that were free from any unknown impurities. Furthermore, annealing treatment was used to increase the length of the ZnO nanorods further at an elevated temperature. This ZnO was used as a buffer layer for polymer solar cells (PSCs) in the device configuration of ITO/ PEDOT:PSS/P3HT-PCBM/ZnO/Ag, in which the Ag cathode was prepared by the inkjet printing method using silver ink. The present study discusses and compares the performance of the devices with and without the ZnO buffer layer.     

常压化学汽相沉积TiOx纳米光学薄膜及其用于太阳电池减反射膜的研究

报道了用常压化学汽相沉积（APCVD）工艺制备TiOx纳米光学薄膜的研究结果，讨论了衬底温度对薄膜结构及折射率的影响，实验验证了太阳电池对光学减反射膜的理论要求，优化了工艺条件，制备的TiOx纳米光学薄膜性能稳定，大面积颜色均匀一致。采用该工艺制备的TiOx减反射膜能使单晶硅太阳电池光电转换效率平均增加10％。