电沉积法制备固态染料敏化太阳能电池(英文)

本文采用一步电化学沉积的方法在导电玻璃上先后沉积了ZnO/染料复合薄膜以及CuSCN薄层,实现仅以电沉积法制备结构为ZnO/染料/CuSCN的固态染料敏化太阳能电池,电池的光电转换效率达到0.1%。在电沉积CuSCN前,脱附电沉积制备的ZnO/染料复合薄膜中的染料以形成多孔ZnO薄膜,然后通过染料再吸附得到染料敏化ZnO纳晶多孔薄膜。在电沉积过程中,ZnO和CuSCN的晶体尺寸、晶体取向和膜层形貌都可以进行比较精准的控制。探讨了影响沉积薄膜形貌和光电转换效率的因素,如旋转圆盘电极的旋转速度、电沉积温度以及染料敏化剂的选择。本文报道的低温电沉积制备全固态太阳能电池的方法为制备柔性染料敏化太阳能电池提供了一种新的思路。     

太阳能电池用减反射膜的制备及性能

采用溶胶-凝胶法制备出纳米多孔SiO2减反射薄膜样品,考察了薄膜制备工艺对其透过率的影响,并用紫外-可见分光光度计对薄膜的光学特性进行表征。研究结果表明,乙醇-盐酸溶液滴入乙醇-正硅酸乙酯溶液、陈化4天、正硅酸乙酯∶乙醇∶水摩尔比为1∶20∶4,单层SiO2膜具有较好的减反射效果,最大透过率可提高4%。     

热处理对电沉积制备CuInGaSe2薄膜的影响

CuInGaSe2薄膜太阳能电池因具有稳定、高效、低成本和环保等特点而受到国内外科学家的重视．采用Mo／钠钙玻璃衬底为研究电极，饱和甘汞电极(SCE)为参比电极，大面积的铂网电极为辅助电极的三电极体系，在钼／钠钙玻璃衬底上利用电沉积技术制备出太阳能电池用的CuInGaSe2薄膜．分析了不同热处理温度对电沉积制备的CuInGaSe2薄膜的影响，结果表明：当热处理温度为450℃时，所制备的CuInGaSe2薄膜的化学组成接近理想的化学计量比，薄膜具有黄铜矿结构，颗粒均匀和致密性较好．     

基材种类对DMSO体系中电沉积碲化铋薄膜热电材料的影响

采用循环伏安、极化曲线和电化学阻抗谱研究了DMSO溶剂体系中Bi(Ⅲ)、Te(Ⅳ)分别在Cu、Ni和Pt金属基材上的还原行为。结果表明,一元体系中Bi(Ⅲ)、Te(Ⅳ)离子在不同金属基体上的还原均为不可逆过程,还原顺序为Pt→Cu→Ni。在Bi–Te二元体系中,还原过程是分步进行的,还原顺序为Pt→Ni→Cu。通过恒电位沉积方式在Cu基体上电沉积制备了Bi–Te薄膜热电材料。分别采用金相显微镜和X射线衍射仪并对其形貌和物相结构进行了表征,并对其塞贝克系数作了测试。在-0.5、-0.6和-0.7 V(相对于饱和甘汞电极)下电沉积制备的薄膜热电材料中均含有Bi_2Te_3以及单质Bi,且表现出N型半导体的特征。     

三阶光学非线性CdS-SiO2复合薄膜的电化学溶胶-凝胶制备及表征

以硝酸镉、硫代乙酰胺(TAA)和正硅酸乙酯(TEOS)为前驱体,通过电化学溶胶-凝胶法在ITO玻璃基底上制备了CdS-SiO2透明薄膜。通过循环伏安实验确定电化学沉积条件,并研究了薄膜的性质。扫描电子显微镜和X射线能谱(EDX)分析表明,薄膜为纳米结构材料,薄膜由元素Si、O、Cd、S组成。X射线衍射(XRD)分析表明,薄膜中含有CdS,并且CdS晶体沿(103)、(202)晶面择优生长。综合EDX和XRD分析结果确认薄膜为CdS-SiO2复合薄膜。Z扫描表明薄膜具有非线性饱和吸收特性以及自散焦特性的非线性折射效应,为三阶光学非线性材料。薄膜三阶非线性极化率((3))较高,数量级达到了10-14(m/V)2。     

纳米钛酸钡薄膜的制备及介电性能

以纳米钛酸钡粉体为原料,采用电泳沉积法制备得到较薄的钛酸钡薄膜。研究了电压、沉积时间和悬浮液浓度对钛酸钡薄膜成膜效果的影响,确定了钛酸钡薄膜的最佳成膜工艺条件:乙酰丙酮-乙醇的混合溶液质量浓度为75 g/L,直流电压为50 V,电泳5 min。采用反复电泳沉积和反复烧结的方法可以有效避免薄膜烧结过程中裂纹的产生。实验还发现钛酸钡薄膜的介点常数具有与钛酸钡陶瓷类似的温度特性。     

Al_2O_3/BaTiO_3复合薄膜制备及低频介电性能研究

采用电泳沉积技术在经三乙醇胺处理的铝电极上成功制备Al_2O_3/BaTiO_3交织结构薄膜,探讨了电泳沉积电压和沉积时间对沉积薄膜低频介电性能的影响。悬浮液中颗粒在较高的电压下运动速度较快,且沉积时间较短时,悬浮液的浸泡作用对沉积薄膜的影响较小,热处理后形成的Al_2O_3/BaTiO_3交织层结构优异,提高低频区的界面极化程度,改善了钛酸钡薄膜低频介电性能。90V/5min的沉积条件为铝基底上电泳沉积制备钛酸钡薄膜的最佳条件,在该条件下制备的钛酸钡薄膜电容值在10m Hz时为1.84μF/cm2,介电损耗仅为0.14。     

电沉积工艺对p-CuSCN薄膜结构及半导体性质的影响

以乙二胺四乙酸二钠(ethylenediamjn tetraacetic acid disodium,EDTA)为鳌合剂,在水溶液络合体系中采用电沉积法制备了CuSCN半导体薄膜,应用电子隧穿成核和表面态热激发机理以及Mott-Schottky曲线分析了沉积电位和温度对薄膜结构和半导体性质的影响.结果表明:室温下,价带电子隧穿产生的电流与表面态空穴热激发电流在同一数量级,表面态空穴热激发电流不随电位改变,价带电子隧穿电流的变化趋势反映了整体电流的变化.随着阴极电位的升高,由于价带电子的隧穿几率变化,晶粒尺寸先减小后增大;半导体空穴浓度减小,p型性质减弱.由于沉积反应受活化能控制,在高温条件下主要表现为晶粒生长,导致晶粒尺寸增大,薄膜致密度降低;同时也使半导体空穴浓度减小,p型性质减弱.     

液相法沉积DLC的表征及交流阻抗谱

分别以乙醇和甲醇为电解液,采用电化学沉积法,在Si(100)表面得到碳薄膜。通过拉曼光谱和傅立叶变换红外光谱分析,证实所制备的薄膜具有类金刚石(DLC)结构特征。利用扫描电子显微镜对不同工艺制备的薄膜进行了表面形貌分析,并研究了样品在0.5mol/LH2SO4溶液中的电化学交流阻抗谱。结果表明,与在乙醇体系中制得的DLC膜相比,在甲醇体系中制得的DLC膜具有更好的表面形貌和更好的抗腐蚀能力。     

NiO薄膜材料的制备及其电化学电容性能

以镍箔为基底,在Ni(NO3)2溶液中,用电沉积法制备Ni(OH)2薄膜,进行热处理后转化为NiO薄膜电极材料。采用X射线衍射(XRD)和场发射扫描电子显微镜(FESEM)表征产物的结构和形貌。用循环伏安法、恒电流充放电等电化学方法系统研究所制样品的电化学性能。研究结果表明,在Ni(NO3)2溶液浓度为0.08 mol.L-1,电压为-0.9 V条件下沉积,并经过250℃热处理制备的NiO薄膜材料属于立方结构,表现出良好的电化学性能,其单电极比电容值达1220 F.g-1。     

Effect of Cr-doping on the physicochemical properties of blue TiO2 and its application in dye-sensitized solar cells via low-temperature fabrication process

Cr-doped blue TiO₂ (Cr-BTiO₂) nanoparticles were fabricated at room temperature using lithium-ethylenediamine (Li-EDA) as reducing agent. The addition of Li-EDA promotes the selective reduction of the rutile phase of TiO₂ into the amorphous phase keeping anatase phase unaltered. Hence, the phase-selective reduction of TiO₂ leads to the formation of blue TiO₂ nanoparticles. Synthesized samples were characterized by equipment fitted with modern technology. The shifting of (101) peak to a lower angle (2θ) in Cr-BTiO₂ in X-ray diffraction (XRD) pattern suggests the successful doping of chromium into TiO₂ lattices. In Raman spectra, the shifting of the active Eg peak of Cr-BTiO₂ nanoparticles to higher wavenumber also suggests the successful substitution of Ti by Cr. The blue TiO₂ and Cr-BTiO₂ show increased absorption of light in the visible region compared to TiO₂ (P25). The modified TiO₂ samples have improved electron-hole separation tendency as predicted by the photoluminescence spectra (PL). Also, doping of Cr- into TiO₂ lattice results the formation of oxygen vacancy as detected by X-ray photoelectron spectroscopy (XPS). Among all samples, Cr-BTiO₂ demonstrated improvement in J_sc and overall incident photon to current conversion efficiency. Therefore, the synthetic effect is thus responsible for the enhancement in efficiency of Cr-BTiO₂ towards the dye-sensitized solar cell (DSSC) by 2.5 and 1.5 times higher than the P25 and blue TiO₂, respectively.     

Efficiency enhancement of non-selenized Cu(In,Ga)Se2 solar cells employing scalable low-cost antireflective coating

In this study, a non-selenized CuInGaSe₂ (CIGS) solar device with textured zinc oxide (ZnO) antireflection coatings was studied. The ZnO nanostructure was fabricated by a low-temperature aqueous solution deposition method. With controlling the morphology of the solution-grown tapered ZnO nanorod coatings, the average reflectance of the CIGS solar device decreased from 8.6% to 2.1%, and the energy conversion efficiency increased from 9.1% to 11.1%. The performance improvement in the CuInGaSe₂ thin-film solar cell was well explained due to the gradual increase of the refractive index between air and the top electrode of solar cell device by the insertion of the ZnO nanostructure. The results demonstrate a potential application of the ZnO nanostructure array for efficient solar device technology.     

Synthesis of a new class of cyclometallated ruthenium(II) complexes and their application in dye-sensitized solar cells

We synthesized a new class of cyclometallated ruthenium(II) complexes, Ru(tctpy)(C^N)(NCS) (1, 2), where C^N is a bidentate cyclometallating ligand such as 2-phenylpyridinato or 2-(4-(2-phenylethynyl)phenyl)pyridinato. Although these complexes exist as stereoisomers, the microwave synthetic technique yielded only one isomer. These compounds act as light sensitizers and have excellent light-harvesting properties, especially in the near-IR region. Therefore, they can be used in dye-sensitized solar cells (DSCs). A DSC sensitized with 2 shows a 10% incident photon-to-current conversion efficiency at 900 nm.     

Adsorption characteristics of Ru(II) dye on carbon nanotubes for organic solar cell

We present a study on the adsorption properties of ruthenium(II) dye (Ru(II) dye) on multi-walled carbon nanotubes (MWNTs). To fabricate dye sensitized solar cells (DSCs) using dye coated MWNTs, we have developed a method to form covalently linked adducts of MWNTs and Ru(II) dye. MWNTs were functionalized by sonication in hydrogen peroxide solution. Ru(II) dye can be attached to the functionalized MWNTs by a synthetic route using Thionyl chloride (SOCl₂) followed by ethylenediamine. The adsorption characteristics were affected by parameters such as chemical oxidation of MWNTs, sonication process, processing temperature and time. The amount of adsorbed Ru(II) dye was effectively affected by treatment temperature of SOCl₂ than any other parameters.     

染料敏化太阳电池中光阳极的研究进展

染料敏化太阳电池(dye-sensitized solar cell,DSC)的光阳极作为其重要的组成部分,在近些年的研究中取得了较大的进展。常用作光阳极的氧化物包括TiO2、ZnO、SnO2、Nb2O5、A12O3等,其中,TiO2因为综合性能表现突出,成为主要研究的光阳极材料。特别是TiO2纳晶薄膜的性质、形貌、结构等均会对DSC光电性能产生较大影响,其性质调节主要通过表面处理、修饰、掺杂等手段,而不同形貌纳米TiO2的研究主要表现在一维结构上,如纳米线、纳米棒等,本文就这些方面的研究情况进行简单归纳总结,分析影响电池性能的关键因素,并对如何更全面、更深入的提高DSC光电性能作简要展望。     

Influence of molecular weight of PEG on the property of polymer gel electrolyte and performance of quasi-solid-state dye-sensitized solar cells

A new kind of polymer gel electrolyte based on poly(acrylic acid)-poly(ethylene glycol) (PAA-PEG) hybrid was synthesized. The factor of molecular weight of PEG in the hybrid plays an important role in determining the liquid electrolyte absorbency of the hybrid and ionic conductivity of the polymer gel electrolyte, sequentially affects the photovoltaic performance of quasi-solid-state dye-sensitized solar cells. Using the hybrid with PEG molecular weight of 20,000, a polymer gel electrolyte with liquid electrolyte absorbency of 6.9 g g⁻¹ and ionic conductivity of 5.35 mS cm⁻¹ was obtained. Based on the polymer gel electrolyte, a quasi-solid-state dye-sensitized solar cell with conversion efficiency of 5.25% was achieved under irradiation of AM 1.5, 100 mW cm⁻².     

Preparation of nanostructure mixed copper-zinc oxide via co-precipitation rout for dye-sensitized solar cells: The influence of blocking layer and Co(II)/Co(III) complex redox shuttle

Mixed copper-zinc oxide nanostructures (average size 43 nm) were effectively fabricated via co-precipitation route. Field-emission scanning electron microscope (FESEM), powder X-ray diffraction (XRD), fourier-transform infrared spectroscopy (FT-IR) and UV–vis diffuse reflectance spectrum (DRS) were used to characterize the properties of the oxides. At the optimized condition, copper-zinc oxide nanostructures were used for fabrication of working electrodes by doctor blade technique on the fluorine-doped tin oxide (FTO) in dye sensitized solar cells. Their photovoltaic behavior were compared with standard using D35 dye and an electrolyte containing [Co(bpy)₃](PF₆)₂, [Co(pby)₃](PF₆)₃, LiClO₄, and 4-tert-butylpyridine (TBP). The ranges of short-circuit current (J_sc) from 0.13 to 0.30 (mA/cm²), open-circuit voltage (V_oc) from 0.20 to 0.51 V, and fill factor from 0.34 to 0.29 were obtained for the DSSCs made using the working electrodes. A titania blocking layer on the copper-zinc oxide surface improve both the open-circuit voltage (V_oc), short-circuit current (J_sc) and the power-conversion efficiency is consequently enhanced by a factor of approximately five.     

Influence of ionic additives NaI/I2 on the properties of polymer gel electrolyte and performance of quasi-solid-state dye-sensitized solar cells

The ionic additives NaI/I₂ in polymer gel electrolyte not only provide cations, but also affect the liquid electrolyte absorbency of the poly(acrylic acid)-poly(ethylene glycol) hybrid, which results in the change of ionic conductivity of polymer gel electrolyte and the photovoltaic performance of quasi-solid-state dye-sensitized solar cell. With the optimized components of liquid electrolyte containing 0.5 M NaI, 0.05 M I₂, 0.4 M pyridine, 70 vol.% γ-butyrolactone and 30 vol.% N-methylpyrrolidone, a 4.74% power conversion efficiency of quasi-solid-state dye-sensitized solar cell was obtained under 100 mW cm⁻² (AM 1.5) irradiation.     

Influence of solvent on the poly (acrylic acid)-oligo-(ethylene glycol) polymer gel electrolyte and the performance of quasi-solid-state dye-sensitized solar cells

The influence of solvents on the property of poly (acrylic acid)-oligo-(ethylene glycol) polymer gel electrolyte and photovoltaic performance of quasi-solid-state dye-sensitized solar cells (DSSCs) were investigated. Solvents or mixed solvents with large donor number enhance the liquid electrolyte absorbency, which further influences the ionic conductivity of polymer gel electrolyte. A polymer gel electrolyte with ionic conductivity of 4.45 mS cm⁻¹ was obtained by using poly (acrylic acid)-oligo-(ethylene glycol) as polymer matrix, and absorbing 30 vol.% N-methyl pyrrolidone and 70 vol.% γ-butyrolactone with 0.5 M NaI and 0.05 M I₂. By using this polymer gel electrolyte coupling with 0.4 M pyridine additive, a quasi-solid-state dye-sensitized solar cell with conversion efficiency of 4.74% was obtained under irradiation of 100 mW cm⁻² (AM 1.5).     

Microstructures and photovoltaic performances of bismuth-ion doped Cu(In,Ga)Se2 films prepared via sputtering process

Bismuth-ion doped Cu(In,Ga)Se₂ (CIGS) solar cells were fabricated via sputtering technique. The influence of bismuth-ion doping on structural and photovoltaic characteristics of the fabricated CIGS films were explored in details. With doping of bismuth ions, the grain sizes of CIGS layers were enhanced appreciably due to liquid-phase sintering with the yielded intermediate compound. The secondary ion mass spectroscopy profile results indicated that the diffusion of bismuth ions into CIGS layers promoted dissemination of gallium species from the back contacts to the surface of CIGS layers. According to Hall measurement analysis, the carrier concentration in CIGS films was enhanced significantly with the doping of bismuth ions in the prepared films. The conversion efficiency of the bismuth-ion doped samples was increased approximately 10% in comparison with undoped samples due to the elevated gallium-ion diffusion and grain growth. Various photovoltaic parameters including saturated current and diode factors of the prepared doped CIGS solar cells were decreased owing to the inhibition of electron-hole recombination. This investigation demonstrated the improved photovoltaic performance and the structural characteristics of fabricated CIGS films after the doping of bismuth ions.